1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Simplified MAC Kernel (smack) security module |
4 | * |
5 | * This file contains the smack hook function implementations. |
6 | * |
7 | * Authors: |
8 | * Casey Schaufler <casey@schaufler-ca.com> |
9 | * Jarkko Sakkinen <jarkko.sakkinen@intel.com> |
10 | * |
11 | * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> |
12 | * Copyright (C) 2009 Hewlett-Packard Development Company, L.P. |
13 | * Paul Moore <paul@paul-moore.com> |
14 | * Copyright (C) 2010 Nokia Corporation |
15 | * Copyright (C) 2011 Intel Corporation. |
16 | */ |
17 | |
18 | #include <linux/xattr.h> |
19 | #include <linux/pagemap.h> |
20 | #include <linux/mount.h> |
21 | #include <linux/stat.h> |
22 | #include <linux/kd.h> |
23 | #include <asm/ioctls.h> |
24 | #include <linux/ip.h> |
25 | #include <linux/tcp.h> |
26 | #include <linux/udp.h> |
27 | #include <linux/dccp.h> |
28 | #include <linux/icmpv6.h> |
29 | #include <linux/slab.h> |
30 | #include <linux/mutex.h> |
31 | #include <net/cipso_ipv4.h> |
32 | #include <net/ip.h> |
33 | #include <net/ipv6.h> |
34 | #include <linux/audit.h> |
35 | #include <linux/magic.h> |
36 | #include <linux/dcache.h> |
37 | #include <linux/personality.h> |
38 | #include <linux/msg.h> |
39 | #include <linux/shm.h> |
40 | #include <linux/binfmts.h> |
41 | #include <linux/parser.h> |
42 | #include <linux/fs_context.h> |
43 | #include <linux/fs_parser.h> |
44 | #include <linux/watch_queue.h> |
45 | #include <linux/io_uring.h> |
46 | #include "smack.h" |
47 | |
48 | #define TRANS_TRUE "TRUE" |
49 | #define TRANS_TRUE_SIZE 4 |
50 | |
51 | #define SMK_CONNECTING 0 |
52 | #define SMK_RECEIVING 1 |
53 | #define SMK_SENDING 2 |
54 | |
55 | /* |
56 | * Smack uses multiple xattrs. |
57 | * SMACK64 - for access control, |
58 | * SMACK64TRANSMUTE - label initialization, |
59 | * Not saved on files - SMACK64IPIN and SMACK64IPOUT, |
60 | * Must be set explicitly - SMACK64EXEC and SMACK64MMAP |
61 | */ |
62 | #define SMACK_INODE_INIT_XATTRS 2 |
63 | |
64 | #ifdef SMACK_IPV6_PORT_LABELING |
65 | static DEFINE_MUTEX(smack_ipv6_lock); |
66 | static LIST_HEAD(smk_ipv6_port_list); |
67 | #endif |
68 | struct kmem_cache *smack_rule_cache; |
69 | int smack_enabled __initdata; |
70 | |
71 | #define A(s) {"smack"#s, sizeof("smack"#s) - 1, Opt_##s} |
72 | static struct { |
73 | const char *name; |
74 | int len; |
75 | int opt; |
76 | } smk_mount_opts[] = { |
77 | {"smackfsdef" , sizeof("smackfsdef" ) - 1, Opt_fsdefault}, |
78 | A(fsdefault), A(fsfloor), A(fshat), A(fsroot), A(fstransmute) |
79 | }; |
80 | #undef A |
81 | |
82 | static int match_opt_prefix(char *s, int l, char **arg) |
83 | { |
84 | int i; |
85 | |
86 | for (i = 0; i < ARRAY_SIZE(smk_mount_opts); i++) { |
87 | size_t len = smk_mount_opts[i].len; |
88 | if (len > l || memcmp(p: s, q: smk_mount_opts[i].name, size: len)) |
89 | continue; |
90 | if (len == l || s[len] != '=') |
91 | continue; |
92 | *arg = s + len + 1; |
93 | return smk_mount_opts[i].opt; |
94 | } |
95 | return Opt_error; |
96 | } |
97 | |
98 | #ifdef CONFIG_SECURITY_SMACK_BRINGUP |
99 | static char *smk_bu_mess[] = { |
100 | "Bringup Error" , /* Unused */ |
101 | "Bringup" , /* SMACK_BRINGUP_ALLOW */ |
102 | "Unconfined Subject" , /* SMACK_UNCONFINED_SUBJECT */ |
103 | "Unconfined Object" , /* SMACK_UNCONFINED_OBJECT */ |
104 | }; |
105 | |
106 | static void smk_bu_mode(int mode, char *s) |
107 | { |
108 | int i = 0; |
109 | |
110 | if (mode & MAY_READ) |
111 | s[i++] = 'r'; |
112 | if (mode & MAY_WRITE) |
113 | s[i++] = 'w'; |
114 | if (mode & MAY_EXEC) |
115 | s[i++] = 'x'; |
116 | if (mode & MAY_APPEND) |
117 | s[i++] = 'a'; |
118 | if (mode & MAY_TRANSMUTE) |
119 | s[i++] = 't'; |
120 | if (mode & MAY_LOCK) |
121 | s[i++] = 'l'; |
122 | if (i == 0) |
123 | s[i++] = '-'; |
124 | s[i] = '\0'; |
125 | } |
126 | #endif |
127 | |
128 | #ifdef CONFIG_SECURITY_SMACK_BRINGUP |
129 | static int smk_bu_note(char *note, struct smack_known *sskp, |
130 | struct smack_known *oskp, int mode, int rc) |
131 | { |
132 | char acc[SMK_NUM_ACCESS_TYPE + 1]; |
133 | |
134 | if (rc <= 0) |
135 | return rc; |
136 | if (rc > SMACK_UNCONFINED_OBJECT) |
137 | rc = 0; |
138 | |
139 | smk_bu_mode(mode, s: acc); |
140 | pr_info("Smack %s: (%s %s %s) %s\n" , smk_bu_mess[rc], |
141 | sskp->smk_known, oskp->smk_known, acc, note); |
142 | return 0; |
143 | } |
144 | #else |
145 | #define smk_bu_note(note, sskp, oskp, mode, RC) (RC) |
146 | #endif |
147 | |
148 | #ifdef CONFIG_SECURITY_SMACK_BRINGUP |
149 | static int smk_bu_current(char *note, struct smack_known *oskp, |
150 | int mode, int rc) |
151 | { |
152 | struct task_smack *tsp = smack_cred(current_cred()); |
153 | char acc[SMK_NUM_ACCESS_TYPE + 1]; |
154 | |
155 | if (rc <= 0) |
156 | return rc; |
157 | if (rc > SMACK_UNCONFINED_OBJECT) |
158 | rc = 0; |
159 | |
160 | smk_bu_mode(mode, s: acc); |
161 | pr_info("Smack %s: (%s %s %s) %s %s\n" , smk_bu_mess[rc], |
162 | tsp->smk_task->smk_known, oskp->smk_known, |
163 | acc, current->comm, note); |
164 | return 0; |
165 | } |
166 | #else |
167 | #define smk_bu_current(note, oskp, mode, RC) (RC) |
168 | #endif |
169 | |
170 | #ifdef CONFIG_SECURITY_SMACK_BRINGUP |
171 | static int smk_bu_task(struct task_struct *otp, int mode, int rc) |
172 | { |
173 | struct task_smack *tsp = smack_cred(current_cred()); |
174 | struct smack_known *smk_task = smk_of_task_struct_obj(t: otp); |
175 | char acc[SMK_NUM_ACCESS_TYPE + 1]; |
176 | |
177 | if (rc <= 0) |
178 | return rc; |
179 | if (rc > SMACK_UNCONFINED_OBJECT) |
180 | rc = 0; |
181 | |
182 | smk_bu_mode(mode, s: acc); |
183 | pr_info("Smack %s: (%s %s %s) %s to %s\n" , smk_bu_mess[rc], |
184 | tsp->smk_task->smk_known, smk_task->smk_known, acc, |
185 | current->comm, otp->comm); |
186 | return 0; |
187 | } |
188 | #else |
189 | #define smk_bu_task(otp, mode, RC) (RC) |
190 | #endif |
191 | |
192 | #ifdef CONFIG_SECURITY_SMACK_BRINGUP |
193 | static int smk_bu_inode(struct inode *inode, int mode, int rc) |
194 | { |
195 | struct task_smack *tsp = smack_cred(current_cred()); |
196 | struct inode_smack *isp = smack_inode(inode); |
197 | char acc[SMK_NUM_ACCESS_TYPE + 1]; |
198 | |
199 | if (isp->smk_flags & SMK_INODE_IMPURE) |
200 | pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n" , |
201 | inode->i_sb->s_id, inode->i_ino, current->comm); |
202 | |
203 | if (rc <= 0) |
204 | return rc; |
205 | if (rc > SMACK_UNCONFINED_OBJECT) |
206 | rc = 0; |
207 | if (rc == SMACK_UNCONFINED_SUBJECT && |
208 | (mode & (MAY_WRITE | MAY_APPEND))) |
209 | isp->smk_flags |= SMK_INODE_IMPURE; |
210 | |
211 | smk_bu_mode(mode, s: acc); |
212 | |
213 | pr_info("Smack %s: (%s %s %s) inode=(%s %ld) %s\n" , smk_bu_mess[rc], |
214 | tsp->smk_task->smk_known, isp->smk_inode->smk_known, acc, |
215 | inode->i_sb->s_id, inode->i_ino, current->comm); |
216 | return 0; |
217 | } |
218 | #else |
219 | #define smk_bu_inode(inode, mode, RC) (RC) |
220 | #endif |
221 | |
222 | #ifdef CONFIG_SECURITY_SMACK_BRINGUP |
223 | static int smk_bu_file(struct file *file, int mode, int rc) |
224 | { |
225 | struct task_smack *tsp = smack_cred(current_cred()); |
226 | struct smack_known *sskp = tsp->smk_task; |
227 | struct inode *inode = file_inode(f: file); |
228 | struct inode_smack *isp = smack_inode(inode); |
229 | char acc[SMK_NUM_ACCESS_TYPE + 1]; |
230 | |
231 | if (isp->smk_flags & SMK_INODE_IMPURE) |
232 | pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n" , |
233 | inode->i_sb->s_id, inode->i_ino, current->comm); |
234 | |
235 | if (rc <= 0) |
236 | return rc; |
237 | if (rc > SMACK_UNCONFINED_OBJECT) |
238 | rc = 0; |
239 | |
240 | smk_bu_mode(mode, s: acc); |
241 | pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n" , smk_bu_mess[rc], |
242 | sskp->smk_known, smk_of_inode(inode)->smk_known, acc, |
243 | inode->i_sb->s_id, inode->i_ino, file, |
244 | current->comm); |
245 | return 0; |
246 | } |
247 | #else |
248 | #define smk_bu_file(file, mode, RC) (RC) |
249 | #endif |
250 | |
251 | #ifdef CONFIG_SECURITY_SMACK_BRINGUP |
252 | static int smk_bu_credfile(const struct cred *cred, struct file *file, |
253 | int mode, int rc) |
254 | { |
255 | struct task_smack *tsp = smack_cred(cred); |
256 | struct smack_known *sskp = tsp->smk_task; |
257 | struct inode *inode = file_inode(f: file); |
258 | struct inode_smack *isp = smack_inode(inode); |
259 | char acc[SMK_NUM_ACCESS_TYPE + 1]; |
260 | |
261 | if (isp->smk_flags & SMK_INODE_IMPURE) |
262 | pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n" , |
263 | inode->i_sb->s_id, inode->i_ino, current->comm); |
264 | |
265 | if (rc <= 0) |
266 | return rc; |
267 | if (rc > SMACK_UNCONFINED_OBJECT) |
268 | rc = 0; |
269 | |
270 | smk_bu_mode(mode, s: acc); |
271 | pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n" , smk_bu_mess[rc], |
272 | sskp->smk_known, smk_of_inode(inode)->smk_known, acc, |
273 | inode->i_sb->s_id, inode->i_ino, file, |
274 | current->comm); |
275 | return 0; |
276 | } |
277 | #else |
278 | #define smk_bu_credfile(cred, file, mode, RC) (RC) |
279 | #endif |
280 | |
281 | /** |
282 | * smk_fetch - Fetch the smack label from a file. |
283 | * @name: type of the label (attribute) |
284 | * @ip: a pointer to the inode |
285 | * @dp: a pointer to the dentry |
286 | * |
287 | * Returns a pointer to the master list entry for the Smack label, |
288 | * NULL if there was no label to fetch, or an error code. |
289 | */ |
290 | static struct smack_known *smk_fetch(const char *name, struct inode *ip, |
291 | struct dentry *dp) |
292 | { |
293 | int rc; |
294 | char *buffer; |
295 | struct smack_known *skp = NULL; |
296 | |
297 | if (!(ip->i_opflags & IOP_XATTR)) |
298 | return ERR_PTR(error: -EOPNOTSUPP); |
299 | |
300 | buffer = kzalloc(SMK_LONGLABEL, GFP_NOFS); |
301 | if (buffer == NULL) |
302 | return ERR_PTR(error: -ENOMEM); |
303 | |
304 | rc = __vfs_getxattr(dp, ip, name, buffer, SMK_LONGLABEL); |
305 | if (rc < 0) |
306 | skp = ERR_PTR(error: rc); |
307 | else if (rc == 0) |
308 | skp = NULL; |
309 | else |
310 | skp = smk_import_entry(buffer, rc); |
311 | |
312 | kfree(objp: buffer); |
313 | |
314 | return skp; |
315 | } |
316 | |
317 | /** |
318 | * init_inode_smack - initialize an inode security blob |
319 | * @inode: inode to extract the info from |
320 | * @skp: a pointer to the Smack label entry to use in the blob |
321 | * |
322 | */ |
323 | static void init_inode_smack(struct inode *inode, struct smack_known *skp) |
324 | { |
325 | struct inode_smack *isp = smack_inode(inode); |
326 | |
327 | isp->smk_inode = skp; |
328 | isp->smk_flags = 0; |
329 | } |
330 | |
331 | /** |
332 | * init_task_smack - initialize a task security blob |
333 | * @tsp: blob to initialize |
334 | * @task: a pointer to the Smack label for the running task |
335 | * @forked: a pointer to the Smack label for the forked task |
336 | * |
337 | */ |
338 | static void init_task_smack(struct task_smack *tsp, struct smack_known *task, |
339 | struct smack_known *forked) |
340 | { |
341 | tsp->smk_task = task; |
342 | tsp->smk_forked = forked; |
343 | INIT_LIST_HEAD(list: &tsp->smk_rules); |
344 | INIT_LIST_HEAD(list: &tsp->smk_relabel); |
345 | mutex_init(&tsp->smk_rules_lock); |
346 | } |
347 | |
348 | /** |
349 | * smk_copy_rules - copy a rule set |
350 | * @nhead: new rules header pointer |
351 | * @ohead: old rules header pointer |
352 | * @gfp: type of the memory for the allocation |
353 | * |
354 | * Returns 0 on success, -ENOMEM on error |
355 | */ |
356 | static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead, |
357 | gfp_t gfp) |
358 | { |
359 | struct smack_rule *nrp; |
360 | struct smack_rule *orp; |
361 | int rc = 0; |
362 | |
363 | list_for_each_entry_rcu(orp, ohead, list) { |
364 | nrp = kmem_cache_zalloc(k: smack_rule_cache, flags: gfp); |
365 | if (nrp == NULL) { |
366 | rc = -ENOMEM; |
367 | break; |
368 | } |
369 | *nrp = *orp; |
370 | list_add_rcu(new: &nrp->list, head: nhead); |
371 | } |
372 | return rc; |
373 | } |
374 | |
375 | /** |
376 | * smk_copy_relabel - copy smk_relabel labels list |
377 | * @nhead: new rules header pointer |
378 | * @ohead: old rules header pointer |
379 | * @gfp: type of the memory for the allocation |
380 | * |
381 | * Returns 0 on success, -ENOMEM on error |
382 | */ |
383 | static int smk_copy_relabel(struct list_head *nhead, struct list_head *ohead, |
384 | gfp_t gfp) |
385 | { |
386 | struct smack_known_list_elem *nklep; |
387 | struct smack_known_list_elem *oklep; |
388 | |
389 | list_for_each_entry(oklep, ohead, list) { |
390 | nklep = kzalloc(size: sizeof(struct smack_known_list_elem), flags: gfp); |
391 | if (nklep == NULL) { |
392 | smk_destroy_label_list(list: nhead); |
393 | return -ENOMEM; |
394 | } |
395 | nklep->smk_label = oklep->smk_label; |
396 | list_add(new: &nklep->list, head: nhead); |
397 | } |
398 | |
399 | return 0; |
400 | } |
401 | |
402 | /** |
403 | * smk_ptrace_mode - helper function for converting PTRACE_MODE_* into MAY_* |
404 | * @mode: input mode in form of PTRACE_MODE_* |
405 | * |
406 | * Returns a converted MAY_* mode usable by smack rules |
407 | */ |
408 | static inline unsigned int smk_ptrace_mode(unsigned int mode) |
409 | { |
410 | if (mode & PTRACE_MODE_ATTACH) |
411 | return MAY_READWRITE; |
412 | if (mode & PTRACE_MODE_READ) |
413 | return MAY_READ; |
414 | |
415 | return 0; |
416 | } |
417 | |
418 | /** |
419 | * smk_ptrace_rule_check - helper for ptrace access |
420 | * @tracer: tracer process |
421 | * @tracee_known: label entry of the process that's about to be traced |
422 | * @mode: ptrace attachment mode (PTRACE_MODE_*) |
423 | * @func: name of the function that called us, used for audit |
424 | * |
425 | * Returns 0 on access granted, -error on error |
426 | */ |
427 | static int smk_ptrace_rule_check(struct task_struct *tracer, |
428 | struct smack_known *tracee_known, |
429 | unsigned int mode, const char *func) |
430 | { |
431 | int rc; |
432 | struct smk_audit_info ad, *saip = NULL; |
433 | struct task_smack *tsp; |
434 | struct smack_known *tracer_known; |
435 | const struct cred *tracercred; |
436 | |
437 | if ((mode & PTRACE_MODE_NOAUDIT) == 0) { |
438 | smk_ad_init(a: &ad, func, LSM_AUDIT_DATA_TASK); |
439 | smk_ad_setfield_u_tsk(a: &ad, t: tracer); |
440 | saip = &ad; |
441 | } |
442 | |
443 | rcu_read_lock(); |
444 | tracercred = __task_cred(tracer); |
445 | tsp = smack_cred(cred: tracercred); |
446 | tracer_known = smk_of_task(tsp); |
447 | |
448 | if ((mode & PTRACE_MODE_ATTACH) && |
449 | (smack_ptrace_rule == SMACK_PTRACE_EXACT || |
450 | smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)) { |
451 | if (tracer_known->smk_known == tracee_known->smk_known) |
452 | rc = 0; |
453 | else if (smack_ptrace_rule == SMACK_PTRACE_DRACONIAN) |
454 | rc = -EACCES; |
455 | else if (smack_privileged_cred(CAP_SYS_PTRACE, cred: tracercred)) |
456 | rc = 0; |
457 | else |
458 | rc = -EACCES; |
459 | |
460 | if (saip) |
461 | smack_log(subject_label: tracer_known->smk_known, |
462 | object_label: tracee_known->smk_known, |
463 | request: 0, result: rc, auditdata: saip); |
464 | |
465 | rcu_read_unlock(); |
466 | return rc; |
467 | } |
468 | |
469 | /* In case of rule==SMACK_PTRACE_DEFAULT or mode==PTRACE_MODE_READ */ |
470 | rc = smk_tskacc(tsp, tracee_known, smk_ptrace_mode(mode), saip); |
471 | |
472 | rcu_read_unlock(); |
473 | return rc; |
474 | } |
475 | |
476 | /* |
477 | * LSM hooks. |
478 | * We he, that is fun! |
479 | */ |
480 | |
481 | /** |
482 | * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH |
483 | * @ctp: child task pointer |
484 | * @mode: ptrace attachment mode (PTRACE_MODE_*) |
485 | * |
486 | * Returns 0 if access is OK, an error code otherwise |
487 | * |
488 | * Do the capability checks. |
489 | */ |
490 | static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode) |
491 | { |
492 | struct smack_known *skp; |
493 | |
494 | skp = smk_of_task_struct_obj(t: ctp); |
495 | |
496 | return smk_ptrace_rule_check(current, tracee_known: skp, mode, func: __func__); |
497 | } |
498 | |
499 | /** |
500 | * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME |
501 | * @ptp: parent task pointer |
502 | * |
503 | * Returns 0 if access is OK, an error code otherwise |
504 | * |
505 | * Do the capability checks, and require PTRACE_MODE_ATTACH. |
506 | */ |
507 | static int smack_ptrace_traceme(struct task_struct *ptp) |
508 | { |
509 | struct smack_known *skp; |
510 | |
511 | skp = smk_of_task(tsp: smack_cred(current_cred())); |
512 | |
513 | return smk_ptrace_rule_check(tracer: ptp, tracee_known: skp, PTRACE_MODE_ATTACH, func: __func__); |
514 | } |
515 | |
516 | /** |
517 | * smack_syslog - Smack approval on syslog |
518 | * @typefrom_file: unused |
519 | * |
520 | * Returns 0 on success, error code otherwise. |
521 | */ |
522 | static int smack_syslog(int typefrom_file) |
523 | { |
524 | int rc = 0; |
525 | struct smack_known *skp = smk_of_current(); |
526 | |
527 | if (smack_privileged(CAP_MAC_OVERRIDE)) |
528 | return 0; |
529 | |
530 | if (smack_syslog_label != NULL && smack_syslog_label != skp) |
531 | rc = -EACCES; |
532 | |
533 | return rc; |
534 | } |
535 | |
536 | /* |
537 | * Superblock Hooks. |
538 | */ |
539 | |
540 | /** |
541 | * smack_sb_alloc_security - allocate a superblock blob |
542 | * @sb: the superblock getting the blob |
543 | * |
544 | * Returns 0 on success or -ENOMEM on error. |
545 | */ |
546 | static int smack_sb_alloc_security(struct super_block *sb) |
547 | { |
548 | struct superblock_smack *sbsp = smack_superblock(superblock: sb); |
549 | |
550 | sbsp->smk_root = &smack_known_floor; |
551 | sbsp->smk_default = &smack_known_floor; |
552 | sbsp->smk_floor = &smack_known_floor; |
553 | sbsp->smk_hat = &smack_known_hat; |
554 | /* |
555 | * SMK_SB_INITIALIZED will be zero from kzalloc. |
556 | */ |
557 | |
558 | return 0; |
559 | } |
560 | |
561 | struct smack_mnt_opts { |
562 | const char *fsdefault; |
563 | const char *fsfloor; |
564 | const char *fshat; |
565 | const char *fsroot; |
566 | const char *fstransmute; |
567 | }; |
568 | |
569 | static void smack_free_mnt_opts(void *mnt_opts) |
570 | { |
571 | kfree(objp: mnt_opts); |
572 | } |
573 | |
574 | static int smack_add_opt(int token, const char *s, void **mnt_opts) |
575 | { |
576 | struct smack_mnt_opts *opts = *mnt_opts; |
577 | struct smack_known *skp; |
578 | |
579 | if (!opts) { |
580 | opts = kzalloc(size: sizeof(struct smack_mnt_opts), GFP_KERNEL); |
581 | if (!opts) |
582 | return -ENOMEM; |
583 | *mnt_opts = opts; |
584 | } |
585 | if (!s) |
586 | return -ENOMEM; |
587 | |
588 | skp = smk_import_entry(s, 0); |
589 | if (IS_ERR(ptr: skp)) |
590 | return PTR_ERR(ptr: skp); |
591 | |
592 | switch (token) { |
593 | case Opt_fsdefault: |
594 | if (opts->fsdefault) |
595 | goto out_opt_err; |
596 | opts->fsdefault = skp->smk_known; |
597 | break; |
598 | case Opt_fsfloor: |
599 | if (opts->fsfloor) |
600 | goto out_opt_err; |
601 | opts->fsfloor = skp->smk_known; |
602 | break; |
603 | case Opt_fshat: |
604 | if (opts->fshat) |
605 | goto out_opt_err; |
606 | opts->fshat = skp->smk_known; |
607 | break; |
608 | case Opt_fsroot: |
609 | if (opts->fsroot) |
610 | goto out_opt_err; |
611 | opts->fsroot = skp->smk_known; |
612 | break; |
613 | case Opt_fstransmute: |
614 | if (opts->fstransmute) |
615 | goto out_opt_err; |
616 | opts->fstransmute = skp->smk_known; |
617 | break; |
618 | } |
619 | return 0; |
620 | |
621 | out_opt_err: |
622 | pr_warn("Smack: duplicate mount options\n" ); |
623 | return -EINVAL; |
624 | } |
625 | |
626 | /** |
627 | * smack_fs_context_submount - Initialise security data for a filesystem context |
628 | * @fc: The filesystem context. |
629 | * @reference: reference superblock |
630 | * |
631 | * Returns 0 on success or -ENOMEM on error. |
632 | */ |
633 | static int smack_fs_context_submount(struct fs_context *fc, |
634 | struct super_block *reference) |
635 | { |
636 | struct superblock_smack *sbsp; |
637 | struct smack_mnt_opts *ctx; |
638 | struct inode_smack *isp; |
639 | |
640 | ctx = kzalloc(size: sizeof(*ctx), GFP_KERNEL); |
641 | if (!ctx) |
642 | return -ENOMEM; |
643 | fc->security = ctx; |
644 | |
645 | sbsp = smack_superblock(superblock: reference); |
646 | isp = smack_inode(inode: reference->s_root->d_inode); |
647 | |
648 | if (sbsp->smk_default) { |
649 | ctx->fsdefault = kstrdup(s: sbsp->smk_default->smk_known, GFP_KERNEL); |
650 | if (!ctx->fsdefault) |
651 | return -ENOMEM; |
652 | } |
653 | |
654 | if (sbsp->smk_floor) { |
655 | ctx->fsfloor = kstrdup(s: sbsp->smk_floor->smk_known, GFP_KERNEL); |
656 | if (!ctx->fsfloor) |
657 | return -ENOMEM; |
658 | } |
659 | |
660 | if (sbsp->smk_hat) { |
661 | ctx->fshat = kstrdup(s: sbsp->smk_hat->smk_known, GFP_KERNEL); |
662 | if (!ctx->fshat) |
663 | return -ENOMEM; |
664 | } |
665 | |
666 | if (isp->smk_flags & SMK_INODE_TRANSMUTE) { |
667 | if (sbsp->smk_root) { |
668 | ctx->fstransmute = kstrdup(s: sbsp->smk_root->smk_known, GFP_KERNEL); |
669 | if (!ctx->fstransmute) |
670 | return -ENOMEM; |
671 | } |
672 | } |
673 | return 0; |
674 | } |
675 | |
676 | /** |
677 | * smack_fs_context_dup - Duplicate the security data on fs_context duplication |
678 | * @fc: The new filesystem context. |
679 | * @src_fc: The source filesystem context being duplicated. |
680 | * |
681 | * Returns 0 on success or -ENOMEM on error. |
682 | */ |
683 | static int smack_fs_context_dup(struct fs_context *fc, |
684 | struct fs_context *src_fc) |
685 | { |
686 | struct smack_mnt_opts *dst, *src = src_fc->security; |
687 | |
688 | if (!src) |
689 | return 0; |
690 | |
691 | fc->security = kzalloc(size: sizeof(struct smack_mnt_opts), GFP_KERNEL); |
692 | if (!fc->security) |
693 | return -ENOMEM; |
694 | |
695 | dst = fc->security; |
696 | dst->fsdefault = src->fsdefault; |
697 | dst->fsfloor = src->fsfloor; |
698 | dst->fshat = src->fshat; |
699 | dst->fsroot = src->fsroot; |
700 | dst->fstransmute = src->fstransmute; |
701 | |
702 | return 0; |
703 | } |
704 | |
705 | static const struct fs_parameter_spec smack_fs_parameters[] = { |
706 | fsparam_string("smackfsdef" , Opt_fsdefault), |
707 | fsparam_string("smackfsdefault" , Opt_fsdefault), |
708 | fsparam_string("smackfsfloor" , Opt_fsfloor), |
709 | fsparam_string("smackfshat" , Opt_fshat), |
710 | fsparam_string("smackfsroot" , Opt_fsroot), |
711 | fsparam_string("smackfstransmute" , Opt_fstransmute), |
712 | {} |
713 | }; |
714 | |
715 | /** |
716 | * smack_fs_context_parse_param - Parse a single mount parameter |
717 | * @fc: The new filesystem context being constructed. |
718 | * @param: The parameter. |
719 | * |
720 | * Returns 0 on success, -ENOPARAM to pass the parameter on or anything else on |
721 | * error. |
722 | */ |
723 | static int smack_fs_context_parse_param(struct fs_context *fc, |
724 | struct fs_parameter *param) |
725 | { |
726 | struct fs_parse_result result; |
727 | int opt, rc; |
728 | |
729 | opt = fs_parse(fc, desc: smack_fs_parameters, param, result: &result); |
730 | if (opt < 0) |
731 | return opt; |
732 | |
733 | rc = smack_add_opt(token: opt, s: param->string, mnt_opts: &fc->security); |
734 | if (!rc) |
735 | param->string = NULL; |
736 | return rc; |
737 | } |
738 | |
739 | static int smack_sb_eat_lsm_opts(char *options, void **mnt_opts) |
740 | { |
741 | char *from = options, *to = options; |
742 | bool first = true; |
743 | |
744 | while (1) { |
745 | char *next = strchr(from, ','); |
746 | int token, len, rc; |
747 | char *arg = NULL; |
748 | |
749 | if (next) |
750 | len = next - from; |
751 | else |
752 | len = strlen(from); |
753 | |
754 | token = match_opt_prefix(s: from, l: len, arg: &arg); |
755 | if (token != Opt_error) { |
756 | arg = kmemdup_nul(s: arg, len: from + len - arg, GFP_KERNEL); |
757 | rc = smack_add_opt(token, s: arg, mnt_opts); |
758 | kfree(objp: arg); |
759 | if (unlikely(rc)) { |
760 | if (*mnt_opts) |
761 | smack_free_mnt_opts(mnt_opts: *mnt_opts); |
762 | *mnt_opts = NULL; |
763 | return rc; |
764 | } |
765 | } else { |
766 | if (!first) { // copy with preceding comma |
767 | from--; |
768 | len++; |
769 | } |
770 | if (to != from) |
771 | memmove(to, from, len); |
772 | to += len; |
773 | first = false; |
774 | } |
775 | if (!from[len]) |
776 | break; |
777 | from += len + 1; |
778 | } |
779 | *to = '\0'; |
780 | return 0; |
781 | } |
782 | |
783 | /** |
784 | * smack_set_mnt_opts - set Smack specific mount options |
785 | * @sb: the file system superblock |
786 | * @mnt_opts: Smack mount options |
787 | * @kern_flags: mount option from kernel space or user space |
788 | * @set_kern_flags: where to store converted mount opts |
789 | * |
790 | * Returns 0 on success, an error code on failure |
791 | * |
792 | * Allow filesystems with binary mount data to explicitly set Smack mount |
793 | * labels. |
794 | */ |
795 | static int smack_set_mnt_opts(struct super_block *sb, |
796 | void *mnt_opts, |
797 | unsigned long kern_flags, |
798 | unsigned long *set_kern_flags) |
799 | { |
800 | struct dentry *root = sb->s_root; |
801 | struct inode *inode = d_backing_inode(upper: root); |
802 | struct superblock_smack *sp = smack_superblock(superblock: sb); |
803 | struct inode_smack *isp; |
804 | struct smack_known *skp; |
805 | struct smack_mnt_opts *opts = mnt_opts; |
806 | bool transmute = false; |
807 | |
808 | if (sp->smk_flags & SMK_SB_INITIALIZED) |
809 | return 0; |
810 | |
811 | if (!smack_privileged(CAP_MAC_ADMIN)) { |
812 | /* |
813 | * Unprivileged mounts don't get to specify Smack values. |
814 | */ |
815 | if (opts) |
816 | return -EPERM; |
817 | /* |
818 | * Unprivileged mounts get root and default from the caller. |
819 | */ |
820 | skp = smk_of_current(); |
821 | sp->smk_root = skp; |
822 | sp->smk_default = skp; |
823 | /* |
824 | * For a handful of fs types with no user-controlled |
825 | * backing store it's okay to trust security labels |
826 | * in the filesystem. The rest are untrusted. |
827 | */ |
828 | if (sb->s_user_ns != &init_user_ns && |
829 | sb->s_magic != SYSFS_MAGIC && sb->s_magic != TMPFS_MAGIC && |
830 | sb->s_magic != RAMFS_MAGIC) { |
831 | transmute = true; |
832 | sp->smk_flags |= SMK_SB_UNTRUSTED; |
833 | } |
834 | } |
835 | |
836 | sp->smk_flags |= SMK_SB_INITIALIZED; |
837 | |
838 | if (opts) { |
839 | if (opts->fsdefault) { |
840 | skp = smk_import_entry(opts->fsdefault, 0); |
841 | if (IS_ERR(ptr: skp)) |
842 | return PTR_ERR(ptr: skp); |
843 | sp->smk_default = skp; |
844 | } |
845 | if (opts->fsfloor) { |
846 | skp = smk_import_entry(opts->fsfloor, 0); |
847 | if (IS_ERR(ptr: skp)) |
848 | return PTR_ERR(ptr: skp); |
849 | sp->smk_floor = skp; |
850 | } |
851 | if (opts->fshat) { |
852 | skp = smk_import_entry(opts->fshat, 0); |
853 | if (IS_ERR(ptr: skp)) |
854 | return PTR_ERR(ptr: skp); |
855 | sp->smk_hat = skp; |
856 | } |
857 | if (opts->fsroot) { |
858 | skp = smk_import_entry(opts->fsroot, 0); |
859 | if (IS_ERR(ptr: skp)) |
860 | return PTR_ERR(ptr: skp); |
861 | sp->smk_root = skp; |
862 | } |
863 | if (opts->fstransmute) { |
864 | skp = smk_import_entry(opts->fstransmute, 0); |
865 | if (IS_ERR(ptr: skp)) |
866 | return PTR_ERR(ptr: skp); |
867 | sp->smk_root = skp; |
868 | transmute = true; |
869 | } |
870 | } |
871 | |
872 | /* |
873 | * Initialize the root inode. |
874 | */ |
875 | init_inode_smack(inode, skp: sp->smk_root); |
876 | |
877 | if (transmute) { |
878 | isp = smack_inode(inode); |
879 | isp->smk_flags |= SMK_INODE_TRANSMUTE; |
880 | } |
881 | |
882 | return 0; |
883 | } |
884 | |
885 | /** |
886 | * smack_sb_statfs - Smack check on statfs |
887 | * @dentry: identifies the file system in question |
888 | * |
889 | * Returns 0 if current can read the floor of the filesystem, |
890 | * and error code otherwise |
891 | */ |
892 | static int smack_sb_statfs(struct dentry *dentry) |
893 | { |
894 | struct superblock_smack *sbp = smack_superblock(superblock: dentry->d_sb); |
895 | int rc; |
896 | struct smk_audit_info ad; |
897 | |
898 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_DENTRY); |
899 | smk_ad_setfield_u_fs_path_dentry(a: &ad, d: dentry); |
900 | |
901 | rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad); |
902 | rc = smk_bu_current(note: "statfs" , oskp: sbp->smk_floor, MAY_READ, rc); |
903 | return rc; |
904 | } |
905 | |
906 | /* |
907 | * BPRM hooks |
908 | */ |
909 | |
910 | /** |
911 | * smack_bprm_creds_for_exec - Update bprm->cred if needed for exec |
912 | * @bprm: the exec information |
913 | * |
914 | * Returns 0 if it gets a blob, -EPERM if exec forbidden and -ENOMEM otherwise |
915 | */ |
916 | static int smack_bprm_creds_for_exec(struct linux_binprm *bprm) |
917 | { |
918 | struct inode *inode = file_inode(f: bprm->file); |
919 | struct task_smack *bsp = smack_cred(cred: bprm->cred); |
920 | struct inode_smack *isp; |
921 | struct superblock_smack *sbsp; |
922 | int rc; |
923 | |
924 | isp = smack_inode(inode); |
925 | if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task) |
926 | return 0; |
927 | |
928 | sbsp = smack_superblock(superblock: inode->i_sb); |
929 | if ((sbsp->smk_flags & SMK_SB_UNTRUSTED) && |
930 | isp->smk_task != sbsp->smk_root) |
931 | return 0; |
932 | |
933 | if (bprm->unsafe & LSM_UNSAFE_PTRACE) { |
934 | struct task_struct *tracer; |
935 | rc = 0; |
936 | |
937 | rcu_read_lock(); |
938 | tracer = ptrace_parent(current); |
939 | if (likely(tracer != NULL)) |
940 | rc = smk_ptrace_rule_check(tracer, |
941 | tracee_known: isp->smk_task, |
942 | PTRACE_MODE_ATTACH, |
943 | func: __func__); |
944 | rcu_read_unlock(); |
945 | |
946 | if (rc != 0) |
947 | return rc; |
948 | } |
949 | if (bprm->unsafe & ~LSM_UNSAFE_PTRACE) |
950 | return -EPERM; |
951 | |
952 | bsp->smk_task = isp->smk_task; |
953 | bprm->per_clear |= PER_CLEAR_ON_SETID; |
954 | |
955 | /* Decide if this is a secure exec. */ |
956 | if (bsp->smk_task != bsp->smk_forked) |
957 | bprm->secureexec = 1; |
958 | |
959 | return 0; |
960 | } |
961 | |
962 | /* |
963 | * Inode hooks |
964 | */ |
965 | |
966 | /** |
967 | * smack_inode_alloc_security - allocate an inode blob |
968 | * @inode: the inode in need of a blob |
969 | * |
970 | * Returns 0 |
971 | */ |
972 | static int smack_inode_alloc_security(struct inode *inode) |
973 | { |
974 | struct smack_known *skp = smk_of_current(); |
975 | |
976 | init_inode_smack(inode, skp); |
977 | return 0; |
978 | } |
979 | |
980 | /** |
981 | * smack_inode_init_security - copy out the smack from an inode |
982 | * @inode: the newly created inode |
983 | * @dir: containing directory object |
984 | * @qstr: unused |
985 | * @xattrs: where to put the attributes |
986 | * @xattr_count: current number of LSM-provided xattrs (updated) |
987 | * |
988 | * Returns 0 if it all works out, -ENOMEM if there's no memory |
989 | */ |
990 | static int smack_inode_init_security(struct inode *inode, struct inode *dir, |
991 | const struct qstr *qstr, |
992 | struct xattr *xattrs, int *xattr_count) |
993 | { |
994 | struct task_smack *tsp = smack_cred(current_cred()); |
995 | struct smack_known *skp = smk_of_task(tsp); |
996 | struct smack_known *isp = smk_of_inode(isp: inode); |
997 | struct smack_known *dsp = smk_of_inode(isp: dir); |
998 | struct xattr *xattr = lsm_get_xattr_slot(xattrs, xattr_count); |
999 | int may; |
1000 | |
1001 | if (xattr) { |
1002 | /* |
1003 | * If equal, transmuting already occurred in |
1004 | * smack_dentry_create_files_as(). No need to check again. |
1005 | */ |
1006 | if (tsp->smk_task != tsp->smk_transmuted) { |
1007 | rcu_read_lock(); |
1008 | may = smk_access_entry(skp->smk_known, dsp->smk_known, |
1009 | &skp->smk_rules); |
1010 | rcu_read_unlock(); |
1011 | } |
1012 | |
1013 | /* |
1014 | * In addition to having smk_task equal to smk_transmuted, |
1015 | * if the access rule allows transmutation and the directory |
1016 | * requests transmutation then by all means transmute. |
1017 | * Mark the inode as changed. |
1018 | */ |
1019 | if ((tsp->smk_task == tsp->smk_transmuted) || |
1020 | (may > 0 && ((may & MAY_TRANSMUTE) != 0) && |
1021 | smk_inode_transmutable(isp: dir))) { |
1022 | struct xattr *xattr_transmute; |
1023 | |
1024 | /* |
1025 | * The caller of smack_dentry_create_files_as() |
1026 | * should have overridden the current cred, so the |
1027 | * inode label was already set correctly in |
1028 | * smack_inode_alloc_security(). |
1029 | */ |
1030 | if (tsp->smk_task != tsp->smk_transmuted) |
1031 | isp = dsp; |
1032 | xattr_transmute = lsm_get_xattr_slot(xattrs, |
1033 | xattr_count); |
1034 | if (xattr_transmute) { |
1035 | xattr_transmute->value = kmemdup(TRANS_TRUE, |
1036 | TRANS_TRUE_SIZE, |
1037 | GFP_NOFS); |
1038 | if (!xattr_transmute->value) |
1039 | return -ENOMEM; |
1040 | |
1041 | xattr_transmute->value_len = TRANS_TRUE_SIZE; |
1042 | xattr_transmute->name = XATTR_SMACK_TRANSMUTE; |
1043 | } |
1044 | } |
1045 | |
1046 | xattr->value = kstrdup(s: isp->smk_known, GFP_NOFS); |
1047 | if (!xattr->value) |
1048 | return -ENOMEM; |
1049 | |
1050 | xattr->value_len = strlen(isp->smk_known); |
1051 | xattr->name = XATTR_SMACK_SUFFIX; |
1052 | } |
1053 | |
1054 | return 0; |
1055 | } |
1056 | |
1057 | /** |
1058 | * smack_inode_link - Smack check on link |
1059 | * @old_dentry: the existing object |
1060 | * @dir: unused |
1061 | * @new_dentry: the new object |
1062 | * |
1063 | * Returns 0 if access is permitted, an error code otherwise |
1064 | */ |
1065 | static int smack_inode_link(struct dentry *old_dentry, struct inode *dir, |
1066 | struct dentry *new_dentry) |
1067 | { |
1068 | struct smack_known *isp; |
1069 | struct smk_audit_info ad; |
1070 | int rc; |
1071 | |
1072 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_DENTRY); |
1073 | smk_ad_setfield_u_fs_path_dentry(a: &ad, d: old_dentry); |
1074 | |
1075 | isp = smk_of_inode(isp: d_backing_inode(upper: old_dentry)); |
1076 | rc = smk_curacc(isp, MAY_WRITE, &ad); |
1077 | rc = smk_bu_inode(inode: d_backing_inode(upper: old_dentry), MAY_WRITE, rc); |
1078 | |
1079 | if (rc == 0 && d_is_positive(dentry: new_dentry)) { |
1080 | isp = smk_of_inode(isp: d_backing_inode(upper: new_dentry)); |
1081 | smk_ad_setfield_u_fs_path_dentry(a: &ad, d: new_dentry); |
1082 | rc = smk_curacc(isp, MAY_WRITE, &ad); |
1083 | rc = smk_bu_inode(inode: d_backing_inode(upper: new_dentry), MAY_WRITE, rc); |
1084 | } |
1085 | |
1086 | return rc; |
1087 | } |
1088 | |
1089 | /** |
1090 | * smack_inode_unlink - Smack check on inode deletion |
1091 | * @dir: containing directory object |
1092 | * @dentry: file to unlink |
1093 | * |
1094 | * Returns 0 if current can write the containing directory |
1095 | * and the object, error code otherwise |
1096 | */ |
1097 | static int smack_inode_unlink(struct inode *dir, struct dentry *dentry) |
1098 | { |
1099 | struct inode *ip = d_backing_inode(upper: dentry); |
1100 | struct smk_audit_info ad; |
1101 | int rc; |
1102 | |
1103 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_DENTRY); |
1104 | smk_ad_setfield_u_fs_path_dentry(a: &ad, d: dentry); |
1105 | |
1106 | /* |
1107 | * You need write access to the thing you're unlinking |
1108 | */ |
1109 | rc = smk_curacc(smk_of_inode(isp: ip), MAY_WRITE, &ad); |
1110 | rc = smk_bu_inode(inode: ip, MAY_WRITE, rc); |
1111 | if (rc == 0) { |
1112 | /* |
1113 | * You also need write access to the containing directory |
1114 | */ |
1115 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_INODE); |
1116 | smk_ad_setfield_u_fs_inode(a: &ad, i: dir); |
1117 | rc = smk_curacc(smk_of_inode(isp: dir), MAY_WRITE, &ad); |
1118 | rc = smk_bu_inode(inode: dir, MAY_WRITE, rc); |
1119 | } |
1120 | return rc; |
1121 | } |
1122 | |
1123 | /** |
1124 | * smack_inode_rmdir - Smack check on directory deletion |
1125 | * @dir: containing directory object |
1126 | * @dentry: directory to unlink |
1127 | * |
1128 | * Returns 0 if current can write the containing directory |
1129 | * and the directory, error code otherwise |
1130 | */ |
1131 | static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry) |
1132 | { |
1133 | struct smk_audit_info ad; |
1134 | int rc; |
1135 | |
1136 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_DENTRY); |
1137 | smk_ad_setfield_u_fs_path_dentry(a: &ad, d: dentry); |
1138 | |
1139 | /* |
1140 | * You need write access to the thing you're removing |
1141 | */ |
1142 | rc = smk_curacc(smk_of_inode(isp: d_backing_inode(upper: dentry)), MAY_WRITE, &ad); |
1143 | rc = smk_bu_inode(inode: d_backing_inode(upper: dentry), MAY_WRITE, rc); |
1144 | if (rc == 0) { |
1145 | /* |
1146 | * You also need write access to the containing directory |
1147 | */ |
1148 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_INODE); |
1149 | smk_ad_setfield_u_fs_inode(a: &ad, i: dir); |
1150 | rc = smk_curacc(smk_of_inode(isp: dir), MAY_WRITE, &ad); |
1151 | rc = smk_bu_inode(inode: dir, MAY_WRITE, rc); |
1152 | } |
1153 | |
1154 | return rc; |
1155 | } |
1156 | |
1157 | /** |
1158 | * smack_inode_rename - Smack check on rename |
1159 | * @old_inode: unused |
1160 | * @old_dentry: the old object |
1161 | * @new_inode: unused |
1162 | * @new_dentry: the new object |
1163 | * |
1164 | * Read and write access is required on both the old and |
1165 | * new directories. |
1166 | * |
1167 | * Returns 0 if access is permitted, an error code otherwise |
1168 | */ |
1169 | static int smack_inode_rename(struct inode *old_inode, |
1170 | struct dentry *old_dentry, |
1171 | struct inode *new_inode, |
1172 | struct dentry *new_dentry) |
1173 | { |
1174 | int rc; |
1175 | struct smack_known *isp; |
1176 | struct smk_audit_info ad; |
1177 | |
1178 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_DENTRY); |
1179 | smk_ad_setfield_u_fs_path_dentry(a: &ad, d: old_dentry); |
1180 | |
1181 | isp = smk_of_inode(isp: d_backing_inode(upper: old_dentry)); |
1182 | rc = smk_curacc(isp, MAY_READWRITE, &ad); |
1183 | rc = smk_bu_inode(inode: d_backing_inode(upper: old_dentry), MAY_READWRITE, rc); |
1184 | |
1185 | if (rc == 0 && d_is_positive(dentry: new_dentry)) { |
1186 | isp = smk_of_inode(isp: d_backing_inode(upper: new_dentry)); |
1187 | smk_ad_setfield_u_fs_path_dentry(a: &ad, d: new_dentry); |
1188 | rc = smk_curacc(isp, MAY_READWRITE, &ad); |
1189 | rc = smk_bu_inode(inode: d_backing_inode(upper: new_dentry), MAY_READWRITE, rc); |
1190 | } |
1191 | return rc; |
1192 | } |
1193 | |
1194 | /** |
1195 | * smack_inode_permission - Smack version of permission() |
1196 | * @inode: the inode in question |
1197 | * @mask: the access requested |
1198 | * |
1199 | * This is the important Smack hook. |
1200 | * |
1201 | * Returns 0 if access is permitted, an error code otherwise |
1202 | */ |
1203 | static int smack_inode_permission(struct inode *inode, int mask) |
1204 | { |
1205 | struct superblock_smack *sbsp = smack_superblock(superblock: inode->i_sb); |
1206 | struct smk_audit_info ad; |
1207 | int no_block = mask & MAY_NOT_BLOCK; |
1208 | int rc; |
1209 | |
1210 | mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND); |
1211 | /* |
1212 | * No permission to check. Existence test. Yup, it's there. |
1213 | */ |
1214 | if (mask == 0) |
1215 | return 0; |
1216 | |
1217 | if (sbsp->smk_flags & SMK_SB_UNTRUSTED) { |
1218 | if (smk_of_inode(isp: inode) != sbsp->smk_root) |
1219 | return -EACCES; |
1220 | } |
1221 | |
1222 | /* May be droppable after audit */ |
1223 | if (no_block) |
1224 | return -ECHILD; |
1225 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_INODE); |
1226 | smk_ad_setfield_u_fs_inode(a: &ad, i: inode); |
1227 | rc = smk_curacc(smk_of_inode(isp: inode), mask, &ad); |
1228 | rc = smk_bu_inode(inode, mode: mask, rc); |
1229 | return rc; |
1230 | } |
1231 | |
1232 | /** |
1233 | * smack_inode_setattr - Smack check for setting attributes |
1234 | * @dentry: the object |
1235 | * @iattr: for the force flag |
1236 | * |
1237 | * Returns 0 if access is permitted, an error code otherwise |
1238 | */ |
1239 | static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr) |
1240 | { |
1241 | struct smk_audit_info ad; |
1242 | int rc; |
1243 | |
1244 | /* |
1245 | * Need to allow for clearing the setuid bit. |
1246 | */ |
1247 | if (iattr->ia_valid & ATTR_FORCE) |
1248 | return 0; |
1249 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_DENTRY); |
1250 | smk_ad_setfield_u_fs_path_dentry(a: &ad, d: dentry); |
1251 | |
1252 | rc = smk_curacc(smk_of_inode(isp: d_backing_inode(upper: dentry)), MAY_WRITE, &ad); |
1253 | rc = smk_bu_inode(inode: d_backing_inode(upper: dentry), MAY_WRITE, rc); |
1254 | return rc; |
1255 | } |
1256 | |
1257 | /** |
1258 | * smack_inode_getattr - Smack check for getting attributes |
1259 | * @path: path to extract the info from |
1260 | * |
1261 | * Returns 0 if access is permitted, an error code otherwise |
1262 | */ |
1263 | static int smack_inode_getattr(const struct path *path) |
1264 | { |
1265 | struct smk_audit_info ad; |
1266 | struct inode *inode = d_backing_inode(upper: path->dentry); |
1267 | int rc; |
1268 | |
1269 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_PATH); |
1270 | smk_ad_setfield_u_fs_path(a: &ad, p: *path); |
1271 | rc = smk_curacc(smk_of_inode(isp: inode), MAY_READ, &ad); |
1272 | rc = smk_bu_inode(inode, MAY_READ, rc); |
1273 | return rc; |
1274 | } |
1275 | |
1276 | /** |
1277 | * smack_inode_setxattr - Smack check for setting xattrs |
1278 | * @idmap: idmap of the mount |
1279 | * @dentry: the object |
1280 | * @name: name of the attribute |
1281 | * @value: value of the attribute |
1282 | * @size: size of the value |
1283 | * @flags: unused |
1284 | * |
1285 | * This protects the Smack attribute explicitly. |
1286 | * |
1287 | * Returns 0 if access is permitted, an error code otherwise |
1288 | */ |
1289 | static int smack_inode_setxattr(struct mnt_idmap *idmap, |
1290 | struct dentry *dentry, const char *name, |
1291 | const void *value, size_t size, int flags) |
1292 | { |
1293 | struct smk_audit_info ad; |
1294 | struct smack_known *skp; |
1295 | int check_priv = 0; |
1296 | int check_import = 0; |
1297 | int check_star = 0; |
1298 | int rc = 0; |
1299 | |
1300 | /* |
1301 | * Check label validity here so import won't fail in post_setxattr |
1302 | */ |
1303 | if (strcmp(name, XATTR_NAME_SMACK) == 0 || |
1304 | strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || |
1305 | strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) { |
1306 | check_priv = 1; |
1307 | check_import = 1; |
1308 | } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0 || |
1309 | strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { |
1310 | check_priv = 1; |
1311 | check_import = 1; |
1312 | check_star = 1; |
1313 | } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) { |
1314 | check_priv = 1; |
1315 | if (size != TRANS_TRUE_SIZE || |
1316 | strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0) |
1317 | rc = -EINVAL; |
1318 | } else |
1319 | rc = cap_inode_setxattr(dentry, name, value, size, flags); |
1320 | |
1321 | if (check_priv && !smack_privileged(CAP_MAC_ADMIN)) |
1322 | rc = -EPERM; |
1323 | |
1324 | if (rc == 0 && check_import) { |
1325 | skp = size ? smk_import_entry(value, size) : NULL; |
1326 | if (IS_ERR(ptr: skp)) |
1327 | rc = PTR_ERR(ptr: skp); |
1328 | else if (skp == NULL || (check_star && |
1329 | (skp == &smack_known_star || skp == &smack_known_web))) |
1330 | rc = -EINVAL; |
1331 | } |
1332 | |
1333 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_DENTRY); |
1334 | smk_ad_setfield_u_fs_path_dentry(a: &ad, d: dentry); |
1335 | |
1336 | if (rc == 0) { |
1337 | rc = smk_curacc(smk_of_inode(isp: d_backing_inode(upper: dentry)), MAY_WRITE, &ad); |
1338 | rc = smk_bu_inode(inode: d_backing_inode(upper: dentry), MAY_WRITE, rc); |
1339 | } |
1340 | |
1341 | return rc; |
1342 | } |
1343 | |
1344 | /** |
1345 | * smack_inode_post_setxattr - Apply the Smack update approved above |
1346 | * @dentry: object |
1347 | * @name: attribute name |
1348 | * @value: attribute value |
1349 | * @size: attribute size |
1350 | * @flags: unused |
1351 | * |
1352 | * Set the pointer in the inode blob to the entry found |
1353 | * in the master label list. |
1354 | */ |
1355 | static void smack_inode_post_setxattr(struct dentry *dentry, const char *name, |
1356 | const void *value, size_t size, int flags) |
1357 | { |
1358 | struct smack_known *skp; |
1359 | struct inode_smack *isp = smack_inode(inode: d_backing_inode(upper: dentry)); |
1360 | |
1361 | if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) { |
1362 | isp->smk_flags |= SMK_INODE_TRANSMUTE; |
1363 | return; |
1364 | } |
1365 | |
1366 | if (strcmp(name, XATTR_NAME_SMACK) == 0) { |
1367 | skp = smk_import_entry(value, size); |
1368 | if (!IS_ERR(ptr: skp)) |
1369 | isp->smk_inode = skp; |
1370 | } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) { |
1371 | skp = smk_import_entry(value, size); |
1372 | if (!IS_ERR(ptr: skp)) |
1373 | isp->smk_task = skp; |
1374 | } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { |
1375 | skp = smk_import_entry(value, size); |
1376 | if (!IS_ERR(ptr: skp)) |
1377 | isp->smk_mmap = skp; |
1378 | } |
1379 | |
1380 | return; |
1381 | } |
1382 | |
1383 | /** |
1384 | * smack_inode_getxattr - Smack check on getxattr |
1385 | * @dentry: the object |
1386 | * @name: unused |
1387 | * |
1388 | * Returns 0 if access is permitted, an error code otherwise |
1389 | */ |
1390 | static int smack_inode_getxattr(struct dentry *dentry, const char *name) |
1391 | { |
1392 | struct smk_audit_info ad; |
1393 | int rc; |
1394 | |
1395 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_DENTRY); |
1396 | smk_ad_setfield_u_fs_path_dentry(a: &ad, d: dentry); |
1397 | |
1398 | rc = smk_curacc(smk_of_inode(isp: d_backing_inode(upper: dentry)), MAY_READ, &ad); |
1399 | rc = smk_bu_inode(inode: d_backing_inode(upper: dentry), MAY_READ, rc); |
1400 | return rc; |
1401 | } |
1402 | |
1403 | /** |
1404 | * smack_inode_removexattr - Smack check on removexattr |
1405 | * @idmap: idmap of the mount |
1406 | * @dentry: the object |
1407 | * @name: name of the attribute |
1408 | * |
1409 | * Removing the Smack attribute requires CAP_MAC_ADMIN |
1410 | * |
1411 | * Returns 0 if access is permitted, an error code otherwise |
1412 | */ |
1413 | static int smack_inode_removexattr(struct mnt_idmap *idmap, |
1414 | struct dentry *dentry, const char *name) |
1415 | { |
1416 | struct inode_smack *isp; |
1417 | struct smk_audit_info ad; |
1418 | int rc = 0; |
1419 | |
1420 | if (strcmp(name, XATTR_NAME_SMACK) == 0 || |
1421 | strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || |
1422 | strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 || |
1423 | strcmp(name, XATTR_NAME_SMACKEXEC) == 0 || |
1424 | strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 || |
1425 | strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { |
1426 | if (!smack_privileged(CAP_MAC_ADMIN)) |
1427 | rc = -EPERM; |
1428 | } else |
1429 | rc = cap_inode_removexattr(idmap, dentry, name); |
1430 | |
1431 | if (rc != 0) |
1432 | return rc; |
1433 | |
1434 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_DENTRY); |
1435 | smk_ad_setfield_u_fs_path_dentry(a: &ad, d: dentry); |
1436 | |
1437 | rc = smk_curacc(smk_of_inode(isp: d_backing_inode(upper: dentry)), MAY_WRITE, &ad); |
1438 | rc = smk_bu_inode(inode: d_backing_inode(upper: dentry), MAY_WRITE, rc); |
1439 | if (rc != 0) |
1440 | return rc; |
1441 | |
1442 | isp = smack_inode(inode: d_backing_inode(upper: dentry)); |
1443 | /* |
1444 | * Don't do anything special for these. |
1445 | * XATTR_NAME_SMACKIPIN |
1446 | * XATTR_NAME_SMACKIPOUT |
1447 | */ |
1448 | if (strcmp(name, XATTR_NAME_SMACK) == 0) { |
1449 | struct super_block *sbp = dentry->d_sb; |
1450 | struct superblock_smack *sbsp = smack_superblock(superblock: sbp); |
1451 | |
1452 | isp->smk_inode = sbsp->smk_default; |
1453 | } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) |
1454 | isp->smk_task = NULL; |
1455 | else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) |
1456 | isp->smk_mmap = NULL; |
1457 | else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) |
1458 | isp->smk_flags &= ~SMK_INODE_TRANSMUTE; |
1459 | |
1460 | return 0; |
1461 | } |
1462 | |
1463 | /** |
1464 | * smack_inode_set_acl - Smack check for setting posix acls |
1465 | * @idmap: idmap of the mnt this request came from |
1466 | * @dentry: the object |
1467 | * @acl_name: name of the posix acl |
1468 | * @kacl: the posix acls |
1469 | * |
1470 | * Returns 0 if access is permitted, an error code otherwise |
1471 | */ |
1472 | static int smack_inode_set_acl(struct mnt_idmap *idmap, |
1473 | struct dentry *dentry, const char *acl_name, |
1474 | struct posix_acl *kacl) |
1475 | { |
1476 | struct smk_audit_info ad; |
1477 | int rc; |
1478 | |
1479 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_DENTRY); |
1480 | smk_ad_setfield_u_fs_path_dentry(a: &ad, d: dentry); |
1481 | |
1482 | rc = smk_curacc(smk_of_inode(isp: d_backing_inode(upper: dentry)), MAY_WRITE, &ad); |
1483 | rc = smk_bu_inode(inode: d_backing_inode(upper: dentry), MAY_WRITE, rc); |
1484 | return rc; |
1485 | } |
1486 | |
1487 | /** |
1488 | * smack_inode_get_acl - Smack check for getting posix acls |
1489 | * @idmap: idmap of the mnt this request came from |
1490 | * @dentry: the object |
1491 | * @acl_name: name of the posix acl |
1492 | * |
1493 | * Returns 0 if access is permitted, an error code otherwise |
1494 | */ |
1495 | static int smack_inode_get_acl(struct mnt_idmap *idmap, |
1496 | struct dentry *dentry, const char *acl_name) |
1497 | { |
1498 | struct smk_audit_info ad; |
1499 | int rc; |
1500 | |
1501 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_DENTRY); |
1502 | smk_ad_setfield_u_fs_path_dentry(a: &ad, d: dentry); |
1503 | |
1504 | rc = smk_curacc(smk_of_inode(isp: d_backing_inode(upper: dentry)), MAY_READ, &ad); |
1505 | rc = smk_bu_inode(inode: d_backing_inode(upper: dentry), MAY_READ, rc); |
1506 | return rc; |
1507 | } |
1508 | |
1509 | /** |
1510 | * smack_inode_remove_acl - Smack check for getting posix acls |
1511 | * @idmap: idmap of the mnt this request came from |
1512 | * @dentry: the object |
1513 | * @acl_name: name of the posix acl |
1514 | * |
1515 | * Returns 0 if access is permitted, an error code otherwise |
1516 | */ |
1517 | static int smack_inode_remove_acl(struct mnt_idmap *idmap, |
1518 | struct dentry *dentry, const char *acl_name) |
1519 | { |
1520 | struct smk_audit_info ad; |
1521 | int rc; |
1522 | |
1523 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_DENTRY); |
1524 | smk_ad_setfield_u_fs_path_dentry(a: &ad, d: dentry); |
1525 | |
1526 | rc = smk_curacc(smk_of_inode(isp: d_backing_inode(upper: dentry)), MAY_WRITE, &ad); |
1527 | rc = smk_bu_inode(inode: d_backing_inode(upper: dentry), MAY_WRITE, rc); |
1528 | return rc; |
1529 | } |
1530 | |
1531 | /** |
1532 | * smack_inode_getsecurity - get smack xattrs |
1533 | * @idmap: idmap of the mount |
1534 | * @inode: the object |
1535 | * @name: attribute name |
1536 | * @buffer: where to put the result |
1537 | * @alloc: duplicate memory |
1538 | * |
1539 | * Returns the size of the attribute or an error code |
1540 | */ |
1541 | static int smack_inode_getsecurity(struct mnt_idmap *idmap, |
1542 | struct inode *inode, const char *name, |
1543 | void **buffer, bool alloc) |
1544 | { |
1545 | struct socket_smack *ssp; |
1546 | struct socket *sock; |
1547 | struct super_block *sbp; |
1548 | struct inode *ip = inode; |
1549 | struct smack_known *isp; |
1550 | struct inode_smack *ispp; |
1551 | size_t label_len; |
1552 | char *label = NULL; |
1553 | |
1554 | if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { |
1555 | isp = smk_of_inode(isp: inode); |
1556 | } else if (strcmp(name, XATTR_SMACK_TRANSMUTE) == 0) { |
1557 | ispp = smack_inode(inode); |
1558 | if (ispp->smk_flags & SMK_INODE_TRANSMUTE) |
1559 | label = TRANS_TRUE; |
1560 | else |
1561 | label = "" ; |
1562 | } else { |
1563 | /* |
1564 | * The rest of the Smack xattrs are only on sockets. |
1565 | */ |
1566 | sbp = ip->i_sb; |
1567 | if (sbp->s_magic != SOCKFS_MAGIC) |
1568 | return -EOPNOTSUPP; |
1569 | |
1570 | sock = SOCKET_I(inode: ip); |
1571 | if (sock == NULL || sock->sk == NULL) |
1572 | return -EOPNOTSUPP; |
1573 | |
1574 | ssp = sock->sk->sk_security; |
1575 | |
1576 | if (strcmp(name, XATTR_SMACK_IPIN) == 0) |
1577 | isp = ssp->smk_in; |
1578 | else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) |
1579 | isp = ssp->smk_out; |
1580 | else |
1581 | return -EOPNOTSUPP; |
1582 | } |
1583 | |
1584 | if (!label) |
1585 | label = isp->smk_known; |
1586 | |
1587 | label_len = strlen(label); |
1588 | |
1589 | if (alloc) { |
1590 | *buffer = kstrdup(s: label, GFP_KERNEL); |
1591 | if (*buffer == NULL) |
1592 | return -ENOMEM; |
1593 | } |
1594 | |
1595 | return label_len; |
1596 | } |
1597 | |
1598 | |
1599 | /** |
1600 | * smack_inode_listsecurity - list the Smack attributes |
1601 | * @inode: the object |
1602 | * @buffer: where they go |
1603 | * @buffer_size: size of buffer |
1604 | */ |
1605 | static int smack_inode_listsecurity(struct inode *inode, char *buffer, |
1606 | size_t buffer_size) |
1607 | { |
1608 | int len = sizeof(XATTR_NAME_SMACK); |
1609 | |
1610 | if (buffer != NULL && len <= buffer_size) |
1611 | memcpy(buffer, XATTR_NAME_SMACK, len); |
1612 | |
1613 | return len; |
1614 | } |
1615 | |
1616 | /** |
1617 | * smack_inode_getsecid - Extract inode's security id |
1618 | * @inode: inode to extract the info from |
1619 | * @secid: where result will be saved |
1620 | */ |
1621 | static void smack_inode_getsecid(struct inode *inode, u32 *secid) |
1622 | { |
1623 | struct smack_known *skp = smk_of_inode(isp: inode); |
1624 | |
1625 | *secid = skp->smk_secid; |
1626 | } |
1627 | |
1628 | /* |
1629 | * File Hooks |
1630 | */ |
1631 | |
1632 | /* |
1633 | * There is no smack_file_permission hook |
1634 | * |
1635 | * Should access checks be done on each read or write? |
1636 | * UNICOS and SELinux say yes. |
1637 | * Trusted Solaris, Trusted Irix, and just about everyone else says no. |
1638 | * |
1639 | * I'll say no for now. Smack does not do the frequent |
1640 | * label changing that SELinux does. |
1641 | */ |
1642 | |
1643 | /** |
1644 | * smack_file_alloc_security - assign a file security blob |
1645 | * @file: the object |
1646 | * |
1647 | * The security blob for a file is a pointer to the master |
1648 | * label list, so no allocation is done. |
1649 | * |
1650 | * f_security is the owner security information. It |
1651 | * isn't used on file access checks, it's for send_sigio. |
1652 | * |
1653 | * Returns 0 |
1654 | */ |
1655 | static int smack_file_alloc_security(struct file *file) |
1656 | { |
1657 | struct smack_known **blob = smack_file(file); |
1658 | |
1659 | *blob = smk_of_current(); |
1660 | return 0; |
1661 | } |
1662 | |
1663 | /** |
1664 | * smack_file_ioctl - Smack check on ioctls |
1665 | * @file: the object |
1666 | * @cmd: what to do |
1667 | * @arg: unused |
1668 | * |
1669 | * Relies heavily on the correct use of the ioctl command conventions. |
1670 | * |
1671 | * Returns 0 if allowed, error code otherwise |
1672 | */ |
1673 | static int smack_file_ioctl(struct file *file, unsigned int cmd, |
1674 | unsigned long arg) |
1675 | { |
1676 | int rc = 0; |
1677 | struct smk_audit_info ad; |
1678 | struct inode *inode = file_inode(f: file); |
1679 | |
1680 | if (unlikely(IS_PRIVATE(inode))) |
1681 | return 0; |
1682 | |
1683 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_PATH); |
1684 | smk_ad_setfield_u_fs_path(a: &ad, p: file->f_path); |
1685 | |
1686 | if (_IOC_DIR(cmd) & _IOC_WRITE) { |
1687 | rc = smk_curacc(smk_of_inode(isp: inode), MAY_WRITE, &ad); |
1688 | rc = smk_bu_file(file, MAY_WRITE, rc); |
1689 | } |
1690 | |
1691 | if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) { |
1692 | rc = smk_curacc(smk_of_inode(isp: inode), MAY_READ, &ad); |
1693 | rc = smk_bu_file(file, MAY_READ, rc); |
1694 | } |
1695 | |
1696 | return rc; |
1697 | } |
1698 | |
1699 | /** |
1700 | * smack_file_lock - Smack check on file locking |
1701 | * @file: the object |
1702 | * @cmd: unused |
1703 | * |
1704 | * Returns 0 if current has lock access, error code otherwise |
1705 | */ |
1706 | static int smack_file_lock(struct file *file, unsigned int cmd) |
1707 | { |
1708 | struct smk_audit_info ad; |
1709 | int rc; |
1710 | struct inode *inode = file_inode(f: file); |
1711 | |
1712 | if (unlikely(IS_PRIVATE(inode))) |
1713 | return 0; |
1714 | |
1715 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_PATH); |
1716 | smk_ad_setfield_u_fs_path(a: &ad, p: file->f_path); |
1717 | rc = smk_curacc(smk_of_inode(isp: inode), MAY_LOCK, &ad); |
1718 | rc = smk_bu_file(file, MAY_LOCK, rc); |
1719 | return rc; |
1720 | } |
1721 | |
1722 | /** |
1723 | * smack_file_fcntl - Smack check on fcntl |
1724 | * @file: the object |
1725 | * @cmd: what action to check |
1726 | * @arg: unused |
1727 | * |
1728 | * Generally these operations are harmless. |
1729 | * File locking operations present an obvious mechanism |
1730 | * for passing information, so they require write access. |
1731 | * |
1732 | * Returns 0 if current has access, error code otherwise |
1733 | */ |
1734 | static int smack_file_fcntl(struct file *file, unsigned int cmd, |
1735 | unsigned long arg) |
1736 | { |
1737 | struct smk_audit_info ad; |
1738 | int rc = 0; |
1739 | struct inode *inode = file_inode(f: file); |
1740 | |
1741 | if (unlikely(IS_PRIVATE(inode))) |
1742 | return 0; |
1743 | |
1744 | switch (cmd) { |
1745 | case F_GETLK: |
1746 | break; |
1747 | case F_SETLK: |
1748 | case F_SETLKW: |
1749 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_PATH); |
1750 | smk_ad_setfield_u_fs_path(a: &ad, p: file->f_path); |
1751 | rc = smk_curacc(smk_of_inode(isp: inode), MAY_LOCK, &ad); |
1752 | rc = smk_bu_file(file, MAY_LOCK, rc); |
1753 | break; |
1754 | case F_SETOWN: |
1755 | case F_SETSIG: |
1756 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_PATH); |
1757 | smk_ad_setfield_u_fs_path(a: &ad, p: file->f_path); |
1758 | rc = smk_curacc(smk_of_inode(isp: inode), MAY_WRITE, &ad); |
1759 | rc = smk_bu_file(file, MAY_WRITE, rc); |
1760 | break; |
1761 | default: |
1762 | break; |
1763 | } |
1764 | |
1765 | return rc; |
1766 | } |
1767 | |
1768 | /** |
1769 | * smack_mmap_file - Check permissions for a mmap operation. |
1770 | * @file: contains the file structure for file to map (may be NULL). |
1771 | * @reqprot: contains the protection requested by the application. |
1772 | * @prot: contains the protection that will be applied by the kernel. |
1773 | * @flags: contains the operational flags. |
1774 | * |
1775 | * The @file may be NULL, e.g. if mapping anonymous memory. |
1776 | * |
1777 | * Return 0 if permission is granted. |
1778 | */ |
1779 | static int smack_mmap_file(struct file *file, |
1780 | unsigned long reqprot, unsigned long prot, |
1781 | unsigned long flags) |
1782 | { |
1783 | struct smack_known *skp; |
1784 | struct smack_known *mkp; |
1785 | struct smack_rule *srp; |
1786 | struct task_smack *tsp; |
1787 | struct smack_known *okp; |
1788 | struct inode_smack *isp; |
1789 | struct superblock_smack *sbsp; |
1790 | int may; |
1791 | int mmay; |
1792 | int tmay; |
1793 | int rc; |
1794 | |
1795 | if (file == NULL) |
1796 | return 0; |
1797 | |
1798 | if (unlikely(IS_PRIVATE(file_inode(file)))) |
1799 | return 0; |
1800 | |
1801 | isp = smack_inode(inode: file_inode(f: file)); |
1802 | if (isp->smk_mmap == NULL) |
1803 | return 0; |
1804 | sbsp = smack_superblock(superblock: file_inode(f: file)->i_sb); |
1805 | if (sbsp->smk_flags & SMK_SB_UNTRUSTED && |
1806 | isp->smk_mmap != sbsp->smk_root) |
1807 | return -EACCES; |
1808 | mkp = isp->smk_mmap; |
1809 | |
1810 | tsp = smack_cred(current_cred()); |
1811 | skp = smk_of_current(); |
1812 | rc = 0; |
1813 | |
1814 | rcu_read_lock(); |
1815 | /* |
1816 | * For each Smack rule associated with the subject |
1817 | * label verify that the SMACK64MMAP also has access |
1818 | * to that rule's object label. |
1819 | */ |
1820 | list_for_each_entry_rcu(srp, &skp->smk_rules, list) { |
1821 | okp = srp->smk_object; |
1822 | /* |
1823 | * Matching labels always allows access. |
1824 | */ |
1825 | if (mkp->smk_known == okp->smk_known) |
1826 | continue; |
1827 | /* |
1828 | * If there is a matching local rule take |
1829 | * that into account as well. |
1830 | */ |
1831 | may = smk_access_entry(srp->smk_subject->smk_known, |
1832 | okp->smk_known, |
1833 | &tsp->smk_rules); |
1834 | if (may == -ENOENT) |
1835 | may = srp->smk_access; |
1836 | else |
1837 | may &= srp->smk_access; |
1838 | /* |
1839 | * If may is zero the SMACK64MMAP subject can't |
1840 | * possibly have less access. |
1841 | */ |
1842 | if (may == 0) |
1843 | continue; |
1844 | |
1845 | /* |
1846 | * Fetch the global list entry. |
1847 | * If there isn't one a SMACK64MMAP subject |
1848 | * can't have as much access as current. |
1849 | */ |
1850 | mmay = smk_access_entry(mkp->smk_known, okp->smk_known, |
1851 | &mkp->smk_rules); |
1852 | if (mmay == -ENOENT) { |
1853 | rc = -EACCES; |
1854 | break; |
1855 | } |
1856 | /* |
1857 | * If there is a local entry it modifies the |
1858 | * potential access, too. |
1859 | */ |
1860 | tmay = smk_access_entry(mkp->smk_known, okp->smk_known, |
1861 | &tsp->smk_rules); |
1862 | if (tmay != -ENOENT) |
1863 | mmay &= tmay; |
1864 | |
1865 | /* |
1866 | * If there is any access available to current that is |
1867 | * not available to a SMACK64MMAP subject |
1868 | * deny access. |
1869 | */ |
1870 | if ((may | mmay) != mmay) { |
1871 | rc = -EACCES; |
1872 | break; |
1873 | } |
1874 | } |
1875 | |
1876 | rcu_read_unlock(); |
1877 | |
1878 | return rc; |
1879 | } |
1880 | |
1881 | /** |
1882 | * smack_file_set_fowner - set the file security blob value |
1883 | * @file: object in question |
1884 | * |
1885 | */ |
1886 | static void smack_file_set_fowner(struct file *file) |
1887 | { |
1888 | struct smack_known **blob = smack_file(file); |
1889 | |
1890 | *blob = smk_of_current(); |
1891 | } |
1892 | |
1893 | /** |
1894 | * smack_file_send_sigiotask - Smack on sigio |
1895 | * @tsk: The target task |
1896 | * @fown: the object the signal come from |
1897 | * @signum: unused |
1898 | * |
1899 | * Allow a privileged task to get signals even if it shouldn't |
1900 | * |
1901 | * Returns 0 if a subject with the object's smack could |
1902 | * write to the task, an error code otherwise. |
1903 | */ |
1904 | static int smack_file_send_sigiotask(struct task_struct *tsk, |
1905 | struct fown_struct *fown, int signum) |
1906 | { |
1907 | struct smack_known **blob; |
1908 | struct smack_known *skp; |
1909 | struct smack_known *tkp = smk_of_task(tsp: smack_cred(cred: tsk->cred)); |
1910 | const struct cred *tcred; |
1911 | struct file *file; |
1912 | int rc; |
1913 | struct smk_audit_info ad; |
1914 | |
1915 | /* |
1916 | * struct fown_struct is never outside the context of a struct file |
1917 | */ |
1918 | file = container_of(fown, struct file, f_owner); |
1919 | |
1920 | /* we don't log here as rc can be overriden */ |
1921 | blob = smack_file(file); |
1922 | skp = *blob; |
1923 | rc = smk_access(skp, tkp, MAY_DELIVER, NULL); |
1924 | rc = smk_bu_note(note: "sigiotask" , sskp: skp, oskp: tkp, MAY_DELIVER, rc); |
1925 | |
1926 | rcu_read_lock(); |
1927 | tcred = __task_cred(tsk); |
1928 | if (rc != 0 && smack_privileged_cred(CAP_MAC_OVERRIDE, cred: tcred)) |
1929 | rc = 0; |
1930 | rcu_read_unlock(); |
1931 | |
1932 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_TASK); |
1933 | smk_ad_setfield_u_tsk(a: &ad, t: tsk); |
1934 | smack_log(subject_label: skp->smk_known, object_label: tkp->smk_known, MAY_DELIVER, result: rc, auditdata: &ad); |
1935 | return rc; |
1936 | } |
1937 | |
1938 | /** |
1939 | * smack_file_receive - Smack file receive check |
1940 | * @file: the object |
1941 | * |
1942 | * Returns 0 if current has access, error code otherwise |
1943 | */ |
1944 | static int smack_file_receive(struct file *file) |
1945 | { |
1946 | int rc; |
1947 | int may = 0; |
1948 | struct smk_audit_info ad; |
1949 | struct inode *inode = file_inode(f: file); |
1950 | struct socket *sock; |
1951 | struct task_smack *tsp; |
1952 | struct socket_smack *ssp; |
1953 | |
1954 | if (unlikely(IS_PRIVATE(inode))) |
1955 | return 0; |
1956 | |
1957 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_PATH); |
1958 | smk_ad_setfield_u_fs_path(a: &ad, p: file->f_path); |
1959 | |
1960 | if (inode->i_sb->s_magic == SOCKFS_MAGIC) { |
1961 | sock = SOCKET_I(inode); |
1962 | ssp = sock->sk->sk_security; |
1963 | tsp = smack_cred(current_cred()); |
1964 | /* |
1965 | * If the receiving process can't write to the |
1966 | * passed socket or if the passed socket can't |
1967 | * write to the receiving process don't accept |
1968 | * the passed socket. |
1969 | */ |
1970 | rc = smk_access(tsp->smk_task, ssp->smk_out, MAY_WRITE, &ad); |
1971 | rc = smk_bu_file(file, mode: may, rc); |
1972 | if (rc < 0) |
1973 | return rc; |
1974 | rc = smk_access(ssp->smk_in, tsp->smk_task, MAY_WRITE, &ad); |
1975 | rc = smk_bu_file(file, mode: may, rc); |
1976 | return rc; |
1977 | } |
1978 | /* |
1979 | * This code relies on bitmasks. |
1980 | */ |
1981 | if (file->f_mode & FMODE_READ) |
1982 | may = MAY_READ; |
1983 | if (file->f_mode & FMODE_WRITE) |
1984 | may |= MAY_WRITE; |
1985 | |
1986 | rc = smk_curacc(smk_of_inode(isp: inode), may, &ad); |
1987 | rc = smk_bu_file(file, mode: may, rc); |
1988 | return rc; |
1989 | } |
1990 | |
1991 | /** |
1992 | * smack_file_open - Smack dentry open processing |
1993 | * @file: the object |
1994 | * |
1995 | * Set the security blob in the file structure. |
1996 | * Allow the open only if the task has read access. There are |
1997 | * many read operations (e.g. fstat) that you can do with an |
1998 | * fd even if you have the file open write-only. |
1999 | * |
2000 | * Returns 0 if current has access, error code otherwise |
2001 | */ |
2002 | static int smack_file_open(struct file *file) |
2003 | { |
2004 | struct task_smack *tsp = smack_cred(cred: file->f_cred); |
2005 | struct inode *inode = file_inode(f: file); |
2006 | struct smk_audit_info ad; |
2007 | int rc; |
2008 | |
2009 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_PATH); |
2010 | smk_ad_setfield_u_fs_path(a: &ad, p: file->f_path); |
2011 | rc = smk_tskacc(tsp, smk_of_inode(isp: inode), MAY_READ, &ad); |
2012 | rc = smk_bu_credfile(cred: file->f_cred, file, MAY_READ, rc); |
2013 | |
2014 | return rc; |
2015 | } |
2016 | |
2017 | /* |
2018 | * Task hooks |
2019 | */ |
2020 | |
2021 | /** |
2022 | * smack_cred_alloc_blank - "allocate" blank task-level security credentials |
2023 | * @cred: the new credentials |
2024 | * @gfp: the atomicity of any memory allocations |
2025 | * |
2026 | * Prepare a blank set of credentials for modification. This must allocate all |
2027 | * the memory the LSM module might require such that cred_transfer() can |
2028 | * complete without error. |
2029 | */ |
2030 | static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp) |
2031 | { |
2032 | init_task_smack(tsp: smack_cred(cred), NULL, NULL); |
2033 | return 0; |
2034 | } |
2035 | |
2036 | |
2037 | /** |
2038 | * smack_cred_free - "free" task-level security credentials |
2039 | * @cred: the credentials in question |
2040 | * |
2041 | */ |
2042 | static void smack_cred_free(struct cred *cred) |
2043 | { |
2044 | struct task_smack *tsp = smack_cred(cred); |
2045 | struct smack_rule *rp; |
2046 | struct list_head *l; |
2047 | struct list_head *n; |
2048 | |
2049 | smk_destroy_label_list(list: &tsp->smk_relabel); |
2050 | |
2051 | list_for_each_safe(l, n, &tsp->smk_rules) { |
2052 | rp = list_entry(l, struct smack_rule, list); |
2053 | list_del(entry: &rp->list); |
2054 | kmem_cache_free(s: smack_rule_cache, objp: rp); |
2055 | } |
2056 | } |
2057 | |
2058 | /** |
2059 | * smack_cred_prepare - prepare new set of credentials for modification |
2060 | * @new: the new credentials |
2061 | * @old: the original credentials |
2062 | * @gfp: the atomicity of any memory allocations |
2063 | * |
2064 | * Prepare a new set of credentials for modification. |
2065 | */ |
2066 | static int smack_cred_prepare(struct cred *new, const struct cred *old, |
2067 | gfp_t gfp) |
2068 | { |
2069 | struct task_smack *old_tsp = smack_cred(cred: old); |
2070 | struct task_smack *new_tsp = smack_cred(cred: new); |
2071 | int rc; |
2072 | |
2073 | init_task_smack(tsp: new_tsp, task: old_tsp->smk_task, forked: old_tsp->smk_task); |
2074 | |
2075 | rc = smk_copy_rules(nhead: &new_tsp->smk_rules, ohead: &old_tsp->smk_rules, gfp); |
2076 | if (rc != 0) |
2077 | return rc; |
2078 | |
2079 | rc = smk_copy_relabel(nhead: &new_tsp->smk_relabel, ohead: &old_tsp->smk_relabel, |
2080 | gfp); |
2081 | return rc; |
2082 | } |
2083 | |
2084 | /** |
2085 | * smack_cred_transfer - Transfer the old credentials to the new credentials |
2086 | * @new: the new credentials |
2087 | * @old: the original credentials |
2088 | * |
2089 | * Fill in a set of blank credentials from another set of credentials. |
2090 | */ |
2091 | static void smack_cred_transfer(struct cred *new, const struct cred *old) |
2092 | { |
2093 | struct task_smack *old_tsp = smack_cred(cred: old); |
2094 | struct task_smack *new_tsp = smack_cred(cred: new); |
2095 | |
2096 | new_tsp->smk_task = old_tsp->smk_task; |
2097 | new_tsp->smk_forked = old_tsp->smk_task; |
2098 | mutex_init(&new_tsp->smk_rules_lock); |
2099 | INIT_LIST_HEAD(list: &new_tsp->smk_rules); |
2100 | |
2101 | /* cbs copy rule list */ |
2102 | } |
2103 | |
2104 | /** |
2105 | * smack_cred_getsecid - get the secid corresponding to a creds structure |
2106 | * @cred: the object creds |
2107 | * @secid: where to put the result |
2108 | * |
2109 | * Sets the secid to contain a u32 version of the smack label. |
2110 | */ |
2111 | static void smack_cred_getsecid(const struct cred *cred, u32 *secid) |
2112 | { |
2113 | struct smack_known *skp; |
2114 | |
2115 | rcu_read_lock(); |
2116 | skp = smk_of_task(tsp: smack_cred(cred)); |
2117 | *secid = skp->smk_secid; |
2118 | rcu_read_unlock(); |
2119 | } |
2120 | |
2121 | /** |
2122 | * smack_kernel_act_as - Set the subjective context in a set of credentials |
2123 | * @new: points to the set of credentials to be modified. |
2124 | * @secid: specifies the security ID to be set |
2125 | * |
2126 | * Set the security data for a kernel service. |
2127 | */ |
2128 | static int smack_kernel_act_as(struct cred *new, u32 secid) |
2129 | { |
2130 | struct task_smack *new_tsp = smack_cred(cred: new); |
2131 | |
2132 | new_tsp->smk_task = smack_from_secid(secid); |
2133 | return 0; |
2134 | } |
2135 | |
2136 | /** |
2137 | * smack_kernel_create_files_as - Set the file creation label in a set of creds |
2138 | * @new: points to the set of credentials to be modified |
2139 | * @inode: points to the inode to use as a reference |
2140 | * |
2141 | * Set the file creation context in a set of credentials to the same |
2142 | * as the objective context of the specified inode |
2143 | */ |
2144 | static int smack_kernel_create_files_as(struct cred *new, |
2145 | struct inode *inode) |
2146 | { |
2147 | struct inode_smack *isp = smack_inode(inode); |
2148 | struct task_smack *tsp = smack_cred(cred: new); |
2149 | |
2150 | tsp->smk_forked = isp->smk_inode; |
2151 | tsp->smk_task = tsp->smk_forked; |
2152 | return 0; |
2153 | } |
2154 | |
2155 | /** |
2156 | * smk_curacc_on_task - helper to log task related access |
2157 | * @p: the task object |
2158 | * @access: the access requested |
2159 | * @caller: name of the calling function for audit |
2160 | * |
2161 | * Return 0 if access is permitted |
2162 | */ |
2163 | static int smk_curacc_on_task(struct task_struct *p, int access, |
2164 | const char *caller) |
2165 | { |
2166 | struct smk_audit_info ad; |
2167 | struct smack_known *skp = smk_of_task_struct_obj(t: p); |
2168 | int rc; |
2169 | |
2170 | smk_ad_init(a: &ad, func: caller, LSM_AUDIT_DATA_TASK); |
2171 | smk_ad_setfield_u_tsk(a: &ad, t: p); |
2172 | rc = smk_curacc(skp, access, &ad); |
2173 | rc = smk_bu_task(otp: p, mode: access, rc); |
2174 | return rc; |
2175 | } |
2176 | |
2177 | /** |
2178 | * smack_task_setpgid - Smack check on setting pgid |
2179 | * @p: the task object |
2180 | * @pgid: unused |
2181 | * |
2182 | * Return 0 if write access is permitted |
2183 | */ |
2184 | static int smack_task_setpgid(struct task_struct *p, pid_t pgid) |
2185 | { |
2186 | return smk_curacc_on_task(p, MAY_WRITE, caller: __func__); |
2187 | } |
2188 | |
2189 | /** |
2190 | * smack_task_getpgid - Smack access check for getpgid |
2191 | * @p: the object task |
2192 | * |
2193 | * Returns 0 if current can read the object task, error code otherwise |
2194 | */ |
2195 | static int smack_task_getpgid(struct task_struct *p) |
2196 | { |
2197 | return smk_curacc_on_task(p, MAY_READ, caller: __func__); |
2198 | } |
2199 | |
2200 | /** |
2201 | * smack_task_getsid - Smack access check for getsid |
2202 | * @p: the object task |
2203 | * |
2204 | * Returns 0 if current can read the object task, error code otherwise |
2205 | */ |
2206 | static int smack_task_getsid(struct task_struct *p) |
2207 | { |
2208 | return smk_curacc_on_task(p, MAY_READ, caller: __func__); |
2209 | } |
2210 | |
2211 | /** |
2212 | * smack_current_getsecid_subj - get the subjective secid of the current task |
2213 | * @secid: where to put the result |
2214 | * |
2215 | * Sets the secid to contain a u32 version of the task's subjective smack label. |
2216 | */ |
2217 | static void smack_current_getsecid_subj(u32 *secid) |
2218 | { |
2219 | struct smack_known *skp = smk_of_current(); |
2220 | |
2221 | *secid = skp->smk_secid; |
2222 | } |
2223 | |
2224 | /** |
2225 | * smack_task_getsecid_obj - get the objective secid of the task |
2226 | * @p: the task |
2227 | * @secid: where to put the result |
2228 | * |
2229 | * Sets the secid to contain a u32 version of the task's objective smack label. |
2230 | */ |
2231 | static void smack_task_getsecid_obj(struct task_struct *p, u32 *secid) |
2232 | { |
2233 | struct smack_known *skp = smk_of_task_struct_obj(t: p); |
2234 | |
2235 | *secid = skp->smk_secid; |
2236 | } |
2237 | |
2238 | /** |
2239 | * smack_task_setnice - Smack check on setting nice |
2240 | * @p: the task object |
2241 | * @nice: unused |
2242 | * |
2243 | * Return 0 if write access is permitted |
2244 | */ |
2245 | static int smack_task_setnice(struct task_struct *p, int nice) |
2246 | { |
2247 | return smk_curacc_on_task(p, MAY_WRITE, caller: __func__); |
2248 | } |
2249 | |
2250 | /** |
2251 | * smack_task_setioprio - Smack check on setting ioprio |
2252 | * @p: the task object |
2253 | * @ioprio: unused |
2254 | * |
2255 | * Return 0 if write access is permitted |
2256 | */ |
2257 | static int smack_task_setioprio(struct task_struct *p, int ioprio) |
2258 | { |
2259 | return smk_curacc_on_task(p, MAY_WRITE, caller: __func__); |
2260 | } |
2261 | |
2262 | /** |
2263 | * smack_task_getioprio - Smack check on reading ioprio |
2264 | * @p: the task object |
2265 | * |
2266 | * Return 0 if read access is permitted |
2267 | */ |
2268 | static int smack_task_getioprio(struct task_struct *p) |
2269 | { |
2270 | return smk_curacc_on_task(p, MAY_READ, caller: __func__); |
2271 | } |
2272 | |
2273 | /** |
2274 | * smack_task_setscheduler - Smack check on setting scheduler |
2275 | * @p: the task object |
2276 | * |
2277 | * Return 0 if read access is permitted |
2278 | */ |
2279 | static int smack_task_setscheduler(struct task_struct *p) |
2280 | { |
2281 | return smk_curacc_on_task(p, MAY_WRITE, caller: __func__); |
2282 | } |
2283 | |
2284 | /** |
2285 | * smack_task_getscheduler - Smack check on reading scheduler |
2286 | * @p: the task object |
2287 | * |
2288 | * Return 0 if read access is permitted |
2289 | */ |
2290 | static int smack_task_getscheduler(struct task_struct *p) |
2291 | { |
2292 | return smk_curacc_on_task(p, MAY_READ, caller: __func__); |
2293 | } |
2294 | |
2295 | /** |
2296 | * smack_task_movememory - Smack check on moving memory |
2297 | * @p: the task object |
2298 | * |
2299 | * Return 0 if write access is permitted |
2300 | */ |
2301 | static int smack_task_movememory(struct task_struct *p) |
2302 | { |
2303 | return smk_curacc_on_task(p, MAY_WRITE, caller: __func__); |
2304 | } |
2305 | |
2306 | /** |
2307 | * smack_task_kill - Smack check on signal delivery |
2308 | * @p: the task object |
2309 | * @info: unused |
2310 | * @sig: unused |
2311 | * @cred: identifies the cred to use in lieu of current's |
2312 | * |
2313 | * Return 0 if write access is permitted |
2314 | * |
2315 | */ |
2316 | static int smack_task_kill(struct task_struct *p, struct kernel_siginfo *info, |
2317 | int sig, const struct cred *cred) |
2318 | { |
2319 | struct smk_audit_info ad; |
2320 | struct smack_known *skp; |
2321 | struct smack_known *tkp = smk_of_task_struct_obj(t: p); |
2322 | int rc; |
2323 | |
2324 | if (!sig) |
2325 | return 0; /* null signal; existence test */ |
2326 | |
2327 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_TASK); |
2328 | smk_ad_setfield_u_tsk(a: &ad, t: p); |
2329 | /* |
2330 | * Sending a signal requires that the sender |
2331 | * can write the receiver. |
2332 | */ |
2333 | if (cred == NULL) { |
2334 | rc = smk_curacc(tkp, MAY_DELIVER, &ad); |
2335 | rc = smk_bu_task(otp: p, MAY_DELIVER, rc); |
2336 | return rc; |
2337 | } |
2338 | /* |
2339 | * If the cred isn't NULL we're dealing with some USB IO |
2340 | * specific behavior. This is not clean. For one thing |
2341 | * we can't take privilege into account. |
2342 | */ |
2343 | skp = smk_of_task(tsp: smack_cred(cred)); |
2344 | rc = smk_access(skp, tkp, MAY_DELIVER, &ad); |
2345 | rc = smk_bu_note(note: "USB signal" , sskp: skp, oskp: tkp, MAY_DELIVER, rc); |
2346 | return rc; |
2347 | } |
2348 | |
2349 | /** |
2350 | * smack_task_to_inode - copy task smack into the inode blob |
2351 | * @p: task to copy from |
2352 | * @inode: inode to copy to |
2353 | * |
2354 | * Sets the smack pointer in the inode security blob |
2355 | */ |
2356 | static void smack_task_to_inode(struct task_struct *p, struct inode *inode) |
2357 | { |
2358 | struct inode_smack *isp = smack_inode(inode); |
2359 | struct smack_known *skp = smk_of_task_struct_obj(t: p); |
2360 | |
2361 | isp->smk_inode = skp; |
2362 | isp->smk_flags |= SMK_INODE_INSTANT; |
2363 | } |
2364 | |
2365 | /* |
2366 | * Socket hooks. |
2367 | */ |
2368 | |
2369 | /** |
2370 | * smack_sk_alloc_security - Allocate a socket blob |
2371 | * @sk: the socket |
2372 | * @family: unused |
2373 | * @gfp_flags: memory allocation flags |
2374 | * |
2375 | * Assign Smack pointers to current |
2376 | * |
2377 | * Returns 0 on success, -ENOMEM is there's no memory |
2378 | */ |
2379 | static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) |
2380 | { |
2381 | struct smack_known *skp = smk_of_current(); |
2382 | struct socket_smack *ssp; |
2383 | |
2384 | ssp = kzalloc(size: sizeof(struct socket_smack), flags: gfp_flags); |
2385 | if (ssp == NULL) |
2386 | return -ENOMEM; |
2387 | |
2388 | /* |
2389 | * Sockets created by kernel threads receive web label. |
2390 | */ |
2391 | if (unlikely(current->flags & PF_KTHREAD)) { |
2392 | ssp->smk_in = &smack_known_web; |
2393 | ssp->smk_out = &smack_known_web; |
2394 | } else { |
2395 | ssp->smk_in = skp; |
2396 | ssp->smk_out = skp; |
2397 | } |
2398 | ssp->smk_packet = NULL; |
2399 | |
2400 | sk->sk_security = ssp; |
2401 | |
2402 | return 0; |
2403 | } |
2404 | |
2405 | /** |
2406 | * smack_sk_free_security - Free a socket blob |
2407 | * @sk: the socket |
2408 | * |
2409 | * Clears the blob pointer |
2410 | */ |
2411 | static void smack_sk_free_security(struct sock *sk) |
2412 | { |
2413 | #ifdef SMACK_IPV6_PORT_LABELING |
2414 | struct smk_port_label *spp; |
2415 | |
2416 | if (sk->sk_family == PF_INET6) { |
2417 | rcu_read_lock(); |
2418 | list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { |
2419 | if (spp->smk_sock != sk) |
2420 | continue; |
2421 | spp->smk_can_reuse = 1; |
2422 | break; |
2423 | } |
2424 | rcu_read_unlock(); |
2425 | } |
2426 | #endif |
2427 | kfree(objp: sk->sk_security); |
2428 | } |
2429 | |
2430 | /** |
2431 | * smack_sk_clone_security - Copy security context |
2432 | * @sk: the old socket |
2433 | * @newsk: the new socket |
2434 | * |
2435 | * Copy the security context of the old socket pointer to the cloned |
2436 | */ |
2437 | static void smack_sk_clone_security(const struct sock *sk, struct sock *newsk) |
2438 | { |
2439 | struct socket_smack *ssp_old = sk->sk_security; |
2440 | struct socket_smack *ssp_new = newsk->sk_security; |
2441 | |
2442 | *ssp_new = *ssp_old; |
2443 | } |
2444 | |
2445 | /** |
2446 | * smack_ipv4host_label - check host based restrictions |
2447 | * @sip: the object end |
2448 | * |
2449 | * looks for host based access restrictions |
2450 | * |
2451 | * This version will only be appropriate for really small sets of single label |
2452 | * hosts. The caller is responsible for ensuring that the RCU read lock is |
2453 | * taken before calling this function. |
2454 | * |
2455 | * Returns the label of the far end or NULL if it's not special. |
2456 | */ |
2457 | static struct smack_known *smack_ipv4host_label(struct sockaddr_in *sip) |
2458 | { |
2459 | struct smk_net4addr *snp; |
2460 | struct in_addr *siap = &sip->sin_addr; |
2461 | |
2462 | if (siap->s_addr == 0) |
2463 | return NULL; |
2464 | |
2465 | list_for_each_entry_rcu(snp, &smk_net4addr_list, list) |
2466 | /* |
2467 | * we break after finding the first match because |
2468 | * the list is sorted from longest to shortest mask |
2469 | * so we have found the most specific match |
2470 | */ |
2471 | if (snp->smk_host.s_addr == |
2472 | (siap->s_addr & snp->smk_mask.s_addr)) |
2473 | return snp->smk_label; |
2474 | |
2475 | return NULL; |
2476 | } |
2477 | |
2478 | /* |
2479 | * smk_ipv6_localhost - Check for local ipv6 host address |
2480 | * @sip: the address |
2481 | * |
2482 | * Returns boolean true if this is the localhost address |
2483 | */ |
2484 | static bool smk_ipv6_localhost(struct sockaddr_in6 *sip) |
2485 | { |
2486 | __be16 *be16p = (__be16 *)&sip->sin6_addr; |
2487 | __be32 *be32p = (__be32 *)&sip->sin6_addr; |
2488 | |
2489 | if (be32p[0] == 0 && be32p[1] == 0 && be32p[2] == 0 && be16p[6] == 0 && |
2490 | ntohs(be16p[7]) == 1) |
2491 | return true; |
2492 | return false; |
2493 | } |
2494 | |
2495 | /** |
2496 | * smack_ipv6host_label - check host based restrictions |
2497 | * @sip: the object end |
2498 | * |
2499 | * looks for host based access restrictions |
2500 | * |
2501 | * This version will only be appropriate for really small sets of single label |
2502 | * hosts. The caller is responsible for ensuring that the RCU read lock is |
2503 | * taken before calling this function. |
2504 | * |
2505 | * Returns the label of the far end or NULL if it's not special. |
2506 | */ |
2507 | static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip) |
2508 | { |
2509 | struct smk_net6addr *snp; |
2510 | struct in6_addr *sap = &sip->sin6_addr; |
2511 | int i; |
2512 | int found = 0; |
2513 | |
2514 | /* |
2515 | * It's local. Don't look for a host label. |
2516 | */ |
2517 | if (smk_ipv6_localhost(sip)) |
2518 | return NULL; |
2519 | |
2520 | list_for_each_entry_rcu(snp, &smk_net6addr_list, list) { |
2521 | /* |
2522 | * If the label is NULL the entry has |
2523 | * been renounced. Ignore it. |
2524 | */ |
2525 | if (snp->smk_label == NULL) |
2526 | continue; |
2527 | /* |
2528 | * we break after finding the first match because |
2529 | * the list is sorted from longest to shortest mask |
2530 | * so we have found the most specific match |
2531 | */ |
2532 | for (found = 1, i = 0; i < 8; i++) { |
2533 | if ((sap->s6_addr16[i] & snp->smk_mask.s6_addr16[i]) != |
2534 | snp->smk_host.s6_addr16[i]) { |
2535 | found = 0; |
2536 | break; |
2537 | } |
2538 | } |
2539 | if (found) |
2540 | return snp->smk_label; |
2541 | } |
2542 | |
2543 | return NULL; |
2544 | } |
2545 | |
2546 | /** |
2547 | * smack_netlbl_add - Set the secattr on a socket |
2548 | * @sk: the socket |
2549 | * |
2550 | * Attach the outbound smack value (smk_out) to the socket. |
2551 | * |
2552 | * Returns 0 on success or an error code |
2553 | */ |
2554 | static int smack_netlbl_add(struct sock *sk) |
2555 | { |
2556 | struct socket_smack *ssp = sk->sk_security; |
2557 | struct smack_known *skp = ssp->smk_out; |
2558 | int rc; |
2559 | |
2560 | local_bh_disable(); |
2561 | bh_lock_sock_nested(sk); |
2562 | |
2563 | rc = netlbl_sock_setattr(sk, family: sk->sk_family, secattr: &skp->smk_netlabel); |
2564 | switch (rc) { |
2565 | case 0: |
2566 | ssp->smk_state = SMK_NETLBL_LABELED; |
2567 | break; |
2568 | case -EDESTADDRREQ: |
2569 | ssp->smk_state = SMK_NETLBL_REQSKB; |
2570 | rc = 0; |
2571 | break; |
2572 | } |
2573 | |
2574 | bh_unlock_sock(sk); |
2575 | local_bh_enable(); |
2576 | |
2577 | return rc; |
2578 | } |
2579 | |
2580 | /** |
2581 | * smack_netlbl_delete - Remove the secattr from a socket |
2582 | * @sk: the socket |
2583 | * |
2584 | * Remove the outbound smack value from a socket |
2585 | */ |
2586 | static void smack_netlbl_delete(struct sock *sk) |
2587 | { |
2588 | struct socket_smack *ssp = sk->sk_security; |
2589 | |
2590 | /* |
2591 | * Take the label off the socket if one is set. |
2592 | */ |
2593 | if (ssp->smk_state != SMK_NETLBL_LABELED) |
2594 | return; |
2595 | |
2596 | local_bh_disable(); |
2597 | bh_lock_sock_nested(sk); |
2598 | netlbl_sock_delattr(sk); |
2599 | bh_unlock_sock(sk); |
2600 | local_bh_enable(); |
2601 | ssp->smk_state = SMK_NETLBL_UNLABELED; |
2602 | } |
2603 | |
2604 | /** |
2605 | * smk_ipv4_check - Perform IPv4 host access checks |
2606 | * @sk: the socket |
2607 | * @sap: the destination address |
2608 | * |
2609 | * Set the correct secattr for the given socket based on the destination |
2610 | * address and perform any outbound access checks needed. |
2611 | * |
2612 | * Returns 0 on success or an error code. |
2613 | * |
2614 | */ |
2615 | static int smk_ipv4_check(struct sock *sk, struct sockaddr_in *sap) |
2616 | { |
2617 | struct smack_known *skp; |
2618 | int rc = 0; |
2619 | struct smack_known *hkp; |
2620 | struct socket_smack *ssp = sk->sk_security; |
2621 | struct smk_audit_info ad; |
2622 | |
2623 | rcu_read_lock(); |
2624 | hkp = smack_ipv4host_label(sip: sap); |
2625 | if (hkp != NULL) { |
2626 | #ifdef CONFIG_AUDIT |
2627 | struct lsm_network_audit net; |
2628 | |
2629 | smk_ad_init_net(a: &ad, func: __func__, LSM_AUDIT_DATA_NET, net: &net); |
2630 | ad.a.u.net->family = sap->sin_family; |
2631 | ad.a.u.net->dport = sap->sin_port; |
2632 | ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr; |
2633 | #endif |
2634 | skp = ssp->smk_out; |
2635 | rc = smk_access(skp, hkp, MAY_WRITE, &ad); |
2636 | rc = smk_bu_note(note: "IPv4 host check" , sskp: skp, oskp: hkp, MAY_WRITE, rc); |
2637 | /* |
2638 | * Clear the socket netlabel if it's set. |
2639 | */ |
2640 | if (!rc) |
2641 | smack_netlbl_delete(sk); |
2642 | } |
2643 | rcu_read_unlock(); |
2644 | |
2645 | return rc; |
2646 | } |
2647 | |
2648 | /** |
2649 | * smk_ipv6_check - check Smack access |
2650 | * @subject: subject Smack label |
2651 | * @object: object Smack label |
2652 | * @address: address |
2653 | * @act: the action being taken |
2654 | * |
2655 | * Check an IPv6 access |
2656 | */ |
2657 | static int smk_ipv6_check(struct smack_known *subject, |
2658 | struct smack_known *object, |
2659 | struct sockaddr_in6 *address, int act) |
2660 | { |
2661 | #ifdef CONFIG_AUDIT |
2662 | struct lsm_network_audit net; |
2663 | #endif |
2664 | struct smk_audit_info ad; |
2665 | int rc; |
2666 | |
2667 | #ifdef CONFIG_AUDIT |
2668 | smk_ad_init_net(a: &ad, func: __func__, LSM_AUDIT_DATA_NET, net: &net); |
2669 | ad.a.u.net->family = PF_INET6; |
2670 | ad.a.u.net->dport = address->sin6_port; |
2671 | if (act == SMK_RECEIVING) |
2672 | ad.a.u.net->v6info.saddr = address->sin6_addr; |
2673 | else |
2674 | ad.a.u.net->v6info.daddr = address->sin6_addr; |
2675 | #endif |
2676 | rc = smk_access(subject, object, MAY_WRITE, &ad); |
2677 | rc = smk_bu_note(note: "IPv6 check" , sskp: subject, oskp: object, MAY_WRITE, rc); |
2678 | return rc; |
2679 | } |
2680 | |
2681 | #ifdef SMACK_IPV6_PORT_LABELING |
2682 | /** |
2683 | * smk_ipv6_port_label - Smack port access table management |
2684 | * @sock: socket |
2685 | * @address: address |
2686 | * |
2687 | * Create or update the port list entry |
2688 | */ |
2689 | static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address) |
2690 | { |
2691 | struct sock *sk = sock->sk; |
2692 | struct sockaddr_in6 *addr6; |
2693 | struct socket_smack *ssp = sock->sk->sk_security; |
2694 | struct smk_port_label *spp; |
2695 | unsigned short port = 0; |
2696 | |
2697 | if (address == NULL) { |
2698 | /* |
2699 | * This operation is changing the Smack information |
2700 | * on the bound socket. Take the changes to the port |
2701 | * as well. |
2702 | */ |
2703 | rcu_read_lock(); |
2704 | list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { |
2705 | if (sk != spp->smk_sock) |
2706 | continue; |
2707 | spp->smk_in = ssp->smk_in; |
2708 | spp->smk_out = ssp->smk_out; |
2709 | rcu_read_unlock(); |
2710 | return; |
2711 | } |
2712 | /* |
2713 | * A NULL address is only used for updating existing |
2714 | * bound entries. If there isn't one, it's OK. |
2715 | */ |
2716 | rcu_read_unlock(); |
2717 | return; |
2718 | } |
2719 | |
2720 | addr6 = (struct sockaddr_in6 *)address; |
2721 | port = ntohs(addr6->sin6_port); |
2722 | /* |
2723 | * This is a special case that is safely ignored. |
2724 | */ |
2725 | if (port == 0) |
2726 | return; |
2727 | |
2728 | /* |
2729 | * Look for an existing port list entry. |
2730 | * This is an indication that a port is getting reused. |
2731 | */ |
2732 | rcu_read_lock(); |
2733 | list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { |
2734 | if (spp->smk_port != port || spp->smk_sock_type != sock->type) |
2735 | continue; |
2736 | if (spp->smk_can_reuse != 1) { |
2737 | rcu_read_unlock(); |
2738 | return; |
2739 | } |
2740 | spp->smk_port = port; |
2741 | spp->smk_sock = sk; |
2742 | spp->smk_in = ssp->smk_in; |
2743 | spp->smk_out = ssp->smk_out; |
2744 | spp->smk_can_reuse = 0; |
2745 | rcu_read_unlock(); |
2746 | return; |
2747 | } |
2748 | rcu_read_unlock(); |
2749 | /* |
2750 | * A new port entry is required. |
2751 | */ |
2752 | spp = kzalloc(sizeof(*spp), GFP_KERNEL); |
2753 | if (spp == NULL) |
2754 | return; |
2755 | |
2756 | spp->smk_port = port; |
2757 | spp->smk_sock = sk; |
2758 | spp->smk_in = ssp->smk_in; |
2759 | spp->smk_out = ssp->smk_out; |
2760 | spp->smk_sock_type = sock->type; |
2761 | spp->smk_can_reuse = 0; |
2762 | |
2763 | mutex_lock(&smack_ipv6_lock); |
2764 | list_add_rcu(&spp->list, &smk_ipv6_port_list); |
2765 | mutex_unlock(&smack_ipv6_lock); |
2766 | return; |
2767 | } |
2768 | |
2769 | /** |
2770 | * smk_ipv6_port_check - check Smack port access |
2771 | * @sk: socket |
2772 | * @address: address |
2773 | * @act: the action being taken |
2774 | * |
2775 | * Create or update the port list entry |
2776 | */ |
2777 | static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address, |
2778 | int act) |
2779 | { |
2780 | struct smk_port_label *spp; |
2781 | struct socket_smack *ssp = sk->sk_security; |
2782 | struct smack_known *skp = NULL; |
2783 | unsigned short port; |
2784 | struct smack_known *object; |
2785 | |
2786 | if (act == SMK_RECEIVING) { |
2787 | skp = smack_ipv6host_label(address); |
2788 | object = ssp->smk_in; |
2789 | } else { |
2790 | skp = ssp->smk_out; |
2791 | object = smack_ipv6host_label(address); |
2792 | } |
2793 | |
2794 | /* |
2795 | * The other end is a single label host. |
2796 | */ |
2797 | if (skp != NULL && object != NULL) |
2798 | return smk_ipv6_check(skp, object, address, act); |
2799 | if (skp == NULL) |
2800 | skp = smack_net_ambient; |
2801 | if (object == NULL) |
2802 | object = smack_net_ambient; |
2803 | |
2804 | /* |
2805 | * It's remote, so port lookup does no good. |
2806 | */ |
2807 | if (!smk_ipv6_localhost(address)) |
2808 | return smk_ipv6_check(skp, object, address, act); |
2809 | |
2810 | /* |
2811 | * It's local so the send check has to have passed. |
2812 | */ |
2813 | if (act == SMK_RECEIVING) |
2814 | return 0; |
2815 | |
2816 | port = ntohs(address->sin6_port); |
2817 | rcu_read_lock(); |
2818 | list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { |
2819 | if (spp->smk_port != port || spp->smk_sock_type != sk->sk_type) |
2820 | continue; |
2821 | object = spp->smk_in; |
2822 | if (act == SMK_CONNECTING) |
2823 | ssp->smk_packet = spp->smk_out; |
2824 | break; |
2825 | } |
2826 | rcu_read_unlock(); |
2827 | |
2828 | return smk_ipv6_check(skp, object, address, act); |
2829 | } |
2830 | #endif |
2831 | |
2832 | /** |
2833 | * smack_inode_setsecurity - set smack xattrs |
2834 | * @inode: the object |
2835 | * @name: attribute name |
2836 | * @value: attribute value |
2837 | * @size: size of the attribute |
2838 | * @flags: unused |
2839 | * |
2840 | * Sets the named attribute in the appropriate blob |
2841 | * |
2842 | * Returns 0 on success, or an error code |
2843 | */ |
2844 | static int smack_inode_setsecurity(struct inode *inode, const char *name, |
2845 | const void *value, size_t size, int flags) |
2846 | { |
2847 | struct smack_known *skp; |
2848 | struct inode_smack *nsp = smack_inode(inode); |
2849 | struct socket_smack *ssp; |
2850 | struct socket *sock; |
2851 | int rc = 0; |
2852 | |
2853 | if (value == NULL || size > SMK_LONGLABEL || size == 0) |
2854 | return -EINVAL; |
2855 | |
2856 | skp = smk_import_entry(value, size); |
2857 | if (IS_ERR(ptr: skp)) |
2858 | return PTR_ERR(ptr: skp); |
2859 | |
2860 | if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { |
2861 | nsp->smk_inode = skp; |
2862 | nsp->smk_flags |= SMK_INODE_INSTANT; |
2863 | return 0; |
2864 | } |
2865 | /* |
2866 | * The rest of the Smack xattrs are only on sockets. |
2867 | */ |
2868 | if (inode->i_sb->s_magic != SOCKFS_MAGIC) |
2869 | return -EOPNOTSUPP; |
2870 | |
2871 | sock = SOCKET_I(inode); |
2872 | if (sock == NULL || sock->sk == NULL) |
2873 | return -EOPNOTSUPP; |
2874 | |
2875 | ssp = sock->sk->sk_security; |
2876 | |
2877 | if (strcmp(name, XATTR_SMACK_IPIN) == 0) |
2878 | ssp->smk_in = skp; |
2879 | else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) { |
2880 | ssp->smk_out = skp; |
2881 | if (sock->sk->sk_family == PF_INET) { |
2882 | rc = smack_netlbl_add(sk: sock->sk); |
2883 | if (rc != 0) |
2884 | printk(KERN_WARNING |
2885 | "Smack: \"%s\" netlbl error %d.\n" , |
2886 | __func__, -rc); |
2887 | } |
2888 | } else |
2889 | return -EOPNOTSUPP; |
2890 | |
2891 | #ifdef SMACK_IPV6_PORT_LABELING |
2892 | if (sock->sk->sk_family == PF_INET6) |
2893 | smk_ipv6_port_label(sock, NULL); |
2894 | #endif |
2895 | |
2896 | return 0; |
2897 | } |
2898 | |
2899 | /** |
2900 | * smack_socket_post_create - finish socket setup |
2901 | * @sock: the socket |
2902 | * @family: protocol family |
2903 | * @type: unused |
2904 | * @protocol: unused |
2905 | * @kern: unused |
2906 | * |
2907 | * Sets the netlabel information on the socket |
2908 | * |
2909 | * Returns 0 on success, and error code otherwise |
2910 | */ |
2911 | static int smack_socket_post_create(struct socket *sock, int family, |
2912 | int type, int protocol, int kern) |
2913 | { |
2914 | struct socket_smack *ssp; |
2915 | |
2916 | if (sock->sk == NULL) |
2917 | return 0; |
2918 | |
2919 | /* |
2920 | * Sockets created by kernel threads receive web label. |
2921 | */ |
2922 | if (unlikely(current->flags & PF_KTHREAD)) { |
2923 | ssp = sock->sk->sk_security; |
2924 | ssp->smk_in = &smack_known_web; |
2925 | ssp->smk_out = &smack_known_web; |
2926 | } |
2927 | |
2928 | if (family != PF_INET) |
2929 | return 0; |
2930 | /* |
2931 | * Set the outbound netlbl. |
2932 | */ |
2933 | return smack_netlbl_add(sk: sock->sk); |
2934 | } |
2935 | |
2936 | /** |
2937 | * smack_socket_socketpair - create socket pair |
2938 | * @socka: one socket |
2939 | * @sockb: another socket |
2940 | * |
2941 | * Cross reference the peer labels for SO_PEERSEC |
2942 | * |
2943 | * Returns 0 |
2944 | */ |
2945 | static int smack_socket_socketpair(struct socket *socka, |
2946 | struct socket *sockb) |
2947 | { |
2948 | struct socket_smack *asp = socka->sk->sk_security; |
2949 | struct socket_smack *bsp = sockb->sk->sk_security; |
2950 | |
2951 | asp->smk_packet = bsp->smk_out; |
2952 | bsp->smk_packet = asp->smk_out; |
2953 | |
2954 | return 0; |
2955 | } |
2956 | |
2957 | #ifdef SMACK_IPV6_PORT_LABELING |
2958 | /** |
2959 | * smack_socket_bind - record port binding information. |
2960 | * @sock: the socket |
2961 | * @address: the port address |
2962 | * @addrlen: size of the address |
2963 | * |
2964 | * Records the label bound to a port. |
2965 | * |
2966 | * Returns 0 on success, and error code otherwise |
2967 | */ |
2968 | static int smack_socket_bind(struct socket *sock, struct sockaddr *address, |
2969 | int addrlen) |
2970 | { |
2971 | if (sock->sk != NULL && sock->sk->sk_family == PF_INET6) { |
2972 | if (addrlen < SIN6_LEN_RFC2133 || |
2973 | address->sa_family != AF_INET6) |
2974 | return -EINVAL; |
2975 | smk_ipv6_port_label(sock, address); |
2976 | } |
2977 | return 0; |
2978 | } |
2979 | #endif /* SMACK_IPV6_PORT_LABELING */ |
2980 | |
2981 | /** |
2982 | * smack_socket_connect - connect access check |
2983 | * @sock: the socket |
2984 | * @sap: the other end |
2985 | * @addrlen: size of sap |
2986 | * |
2987 | * Verifies that a connection may be possible |
2988 | * |
2989 | * Returns 0 on success, and error code otherwise |
2990 | */ |
2991 | static int smack_socket_connect(struct socket *sock, struct sockaddr *sap, |
2992 | int addrlen) |
2993 | { |
2994 | int rc = 0; |
2995 | |
2996 | if (sock->sk == NULL) |
2997 | return 0; |
2998 | if (sock->sk->sk_family != PF_INET && |
2999 | (!IS_ENABLED(CONFIG_IPV6) || sock->sk->sk_family != PF_INET6)) |
3000 | return 0; |
3001 | if (addrlen < offsetofend(struct sockaddr, sa_family)) |
3002 | return 0; |
3003 | if (IS_ENABLED(CONFIG_IPV6) && sap->sa_family == AF_INET6) { |
3004 | struct sockaddr_in6 *sip = (struct sockaddr_in6 *)sap; |
3005 | struct smack_known *rsp = NULL; |
3006 | |
3007 | if (addrlen < SIN6_LEN_RFC2133) |
3008 | return 0; |
3009 | if (__is_defined(SMACK_IPV6_SECMARK_LABELING)) |
3010 | rsp = smack_ipv6host_label(sip); |
3011 | if (rsp != NULL) { |
3012 | struct socket_smack *ssp = sock->sk->sk_security; |
3013 | |
3014 | rc = smk_ipv6_check(subject: ssp->smk_out, object: rsp, address: sip, |
3015 | SMK_CONNECTING); |
3016 | } |
3017 | #ifdef SMACK_IPV6_PORT_LABELING |
3018 | rc = smk_ipv6_port_check(sock->sk, sip, SMK_CONNECTING); |
3019 | #endif |
3020 | |
3021 | return rc; |
3022 | } |
3023 | if (sap->sa_family != AF_INET || addrlen < sizeof(struct sockaddr_in)) |
3024 | return 0; |
3025 | rc = smk_ipv4_check(sk: sock->sk, sap: (struct sockaddr_in *)sap); |
3026 | return rc; |
3027 | } |
3028 | |
3029 | /** |
3030 | * smack_flags_to_may - convert S_ to MAY_ values |
3031 | * @flags: the S_ value |
3032 | * |
3033 | * Returns the equivalent MAY_ value |
3034 | */ |
3035 | static int smack_flags_to_may(int flags) |
3036 | { |
3037 | int may = 0; |
3038 | |
3039 | if (flags & S_IRUGO) |
3040 | may |= MAY_READ; |
3041 | if (flags & S_IWUGO) |
3042 | may |= MAY_WRITE; |
3043 | if (flags & S_IXUGO) |
3044 | may |= MAY_EXEC; |
3045 | |
3046 | return may; |
3047 | } |
3048 | |
3049 | /** |
3050 | * smack_msg_msg_alloc_security - Set the security blob for msg_msg |
3051 | * @msg: the object |
3052 | * |
3053 | * Returns 0 |
3054 | */ |
3055 | static int smack_msg_msg_alloc_security(struct msg_msg *msg) |
3056 | { |
3057 | struct smack_known **blob = smack_msg_msg(msg); |
3058 | |
3059 | *blob = smk_of_current(); |
3060 | return 0; |
3061 | } |
3062 | |
3063 | /** |
3064 | * smack_of_ipc - the smack pointer for the ipc |
3065 | * @isp: the object |
3066 | * |
3067 | * Returns a pointer to the smack value |
3068 | */ |
3069 | static struct smack_known *smack_of_ipc(struct kern_ipc_perm *isp) |
3070 | { |
3071 | struct smack_known **blob = smack_ipc(ipc: isp); |
3072 | |
3073 | return *blob; |
3074 | } |
3075 | |
3076 | /** |
3077 | * smack_ipc_alloc_security - Set the security blob for ipc |
3078 | * @isp: the object |
3079 | * |
3080 | * Returns 0 |
3081 | */ |
3082 | static int smack_ipc_alloc_security(struct kern_ipc_perm *isp) |
3083 | { |
3084 | struct smack_known **blob = smack_ipc(ipc: isp); |
3085 | |
3086 | *blob = smk_of_current(); |
3087 | return 0; |
3088 | } |
3089 | |
3090 | /** |
3091 | * smk_curacc_shm : check if current has access on shm |
3092 | * @isp : the object |
3093 | * @access : access requested |
3094 | * |
3095 | * Returns 0 if current has the requested access, error code otherwise |
3096 | */ |
3097 | static int smk_curacc_shm(struct kern_ipc_perm *isp, int access) |
3098 | { |
3099 | struct smack_known *ssp = smack_of_ipc(isp); |
3100 | struct smk_audit_info ad; |
3101 | int rc; |
3102 | |
3103 | #ifdef CONFIG_AUDIT |
3104 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_IPC); |
3105 | ad.a.u.ipc_id = isp->id; |
3106 | #endif |
3107 | rc = smk_curacc(ssp, access, &ad); |
3108 | rc = smk_bu_current(note: "shm" , oskp: ssp, mode: access, rc); |
3109 | return rc; |
3110 | } |
3111 | |
3112 | /** |
3113 | * smack_shm_associate - Smack access check for shm |
3114 | * @isp: the object |
3115 | * @shmflg: access requested |
3116 | * |
3117 | * Returns 0 if current has the requested access, error code otherwise |
3118 | */ |
3119 | static int smack_shm_associate(struct kern_ipc_perm *isp, int shmflg) |
3120 | { |
3121 | int may; |
3122 | |
3123 | may = smack_flags_to_may(flags: shmflg); |
3124 | return smk_curacc_shm(isp, access: may); |
3125 | } |
3126 | |
3127 | /** |
3128 | * smack_shm_shmctl - Smack access check for shm |
3129 | * @isp: the object |
3130 | * @cmd: what it wants to do |
3131 | * |
3132 | * Returns 0 if current has the requested access, error code otherwise |
3133 | */ |
3134 | static int smack_shm_shmctl(struct kern_ipc_perm *isp, int cmd) |
3135 | { |
3136 | int may; |
3137 | |
3138 | switch (cmd) { |
3139 | case IPC_STAT: |
3140 | case SHM_STAT: |
3141 | case SHM_STAT_ANY: |
3142 | may = MAY_READ; |
3143 | break; |
3144 | case IPC_SET: |
3145 | case SHM_LOCK: |
3146 | case SHM_UNLOCK: |
3147 | case IPC_RMID: |
3148 | may = MAY_READWRITE; |
3149 | break; |
3150 | case IPC_INFO: |
3151 | case SHM_INFO: |
3152 | /* |
3153 | * System level information. |
3154 | */ |
3155 | return 0; |
3156 | default: |
3157 | return -EINVAL; |
3158 | } |
3159 | return smk_curacc_shm(isp, access: may); |
3160 | } |
3161 | |
3162 | /** |
3163 | * smack_shm_shmat - Smack access for shmat |
3164 | * @isp: the object |
3165 | * @shmaddr: unused |
3166 | * @shmflg: access requested |
3167 | * |
3168 | * Returns 0 if current has the requested access, error code otherwise |
3169 | */ |
3170 | static int smack_shm_shmat(struct kern_ipc_perm *isp, char __user *shmaddr, |
3171 | int shmflg) |
3172 | { |
3173 | int may; |
3174 | |
3175 | may = smack_flags_to_may(flags: shmflg); |
3176 | return smk_curacc_shm(isp, access: may); |
3177 | } |
3178 | |
3179 | /** |
3180 | * smk_curacc_sem : check if current has access on sem |
3181 | * @isp : the object |
3182 | * @access : access requested |
3183 | * |
3184 | * Returns 0 if current has the requested access, error code otherwise |
3185 | */ |
3186 | static int smk_curacc_sem(struct kern_ipc_perm *isp, int access) |
3187 | { |
3188 | struct smack_known *ssp = smack_of_ipc(isp); |
3189 | struct smk_audit_info ad; |
3190 | int rc; |
3191 | |
3192 | #ifdef CONFIG_AUDIT |
3193 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_IPC); |
3194 | ad.a.u.ipc_id = isp->id; |
3195 | #endif |
3196 | rc = smk_curacc(ssp, access, &ad); |
3197 | rc = smk_bu_current(note: "sem" , oskp: ssp, mode: access, rc); |
3198 | return rc; |
3199 | } |
3200 | |
3201 | /** |
3202 | * smack_sem_associate - Smack access check for sem |
3203 | * @isp: the object |
3204 | * @semflg: access requested |
3205 | * |
3206 | * Returns 0 if current has the requested access, error code otherwise |
3207 | */ |
3208 | static int smack_sem_associate(struct kern_ipc_perm *isp, int semflg) |
3209 | { |
3210 | int may; |
3211 | |
3212 | may = smack_flags_to_may(flags: semflg); |
3213 | return smk_curacc_sem(isp, access: may); |
3214 | } |
3215 | |
3216 | /** |
3217 | * smack_sem_semctl - Smack access check for sem |
3218 | * @isp: the object |
3219 | * @cmd: what it wants to do |
3220 | * |
3221 | * Returns 0 if current has the requested access, error code otherwise |
3222 | */ |
3223 | static int smack_sem_semctl(struct kern_ipc_perm *isp, int cmd) |
3224 | { |
3225 | int may; |
3226 | |
3227 | switch (cmd) { |
3228 | case GETPID: |
3229 | case GETNCNT: |
3230 | case GETZCNT: |
3231 | case GETVAL: |
3232 | case GETALL: |
3233 | case IPC_STAT: |
3234 | case SEM_STAT: |
3235 | case SEM_STAT_ANY: |
3236 | may = MAY_READ; |
3237 | break; |
3238 | case SETVAL: |
3239 | case SETALL: |
3240 | case IPC_RMID: |
3241 | case IPC_SET: |
3242 | may = MAY_READWRITE; |
3243 | break; |
3244 | case IPC_INFO: |
3245 | case SEM_INFO: |
3246 | /* |
3247 | * System level information |
3248 | */ |
3249 | return 0; |
3250 | default: |
3251 | return -EINVAL; |
3252 | } |
3253 | |
3254 | return smk_curacc_sem(isp, access: may); |
3255 | } |
3256 | |
3257 | /** |
3258 | * smack_sem_semop - Smack checks of semaphore operations |
3259 | * @isp: the object |
3260 | * @sops: unused |
3261 | * @nsops: unused |
3262 | * @alter: unused |
3263 | * |
3264 | * Treated as read and write in all cases. |
3265 | * |
3266 | * Returns 0 if access is allowed, error code otherwise |
3267 | */ |
3268 | static int smack_sem_semop(struct kern_ipc_perm *isp, struct sembuf *sops, |
3269 | unsigned nsops, int alter) |
3270 | { |
3271 | return smk_curacc_sem(isp, MAY_READWRITE); |
3272 | } |
3273 | |
3274 | /** |
3275 | * smk_curacc_msq : helper to check if current has access on msq |
3276 | * @isp : the msq |
3277 | * @access : access requested |
3278 | * |
3279 | * return 0 if current has access, error otherwise |
3280 | */ |
3281 | static int smk_curacc_msq(struct kern_ipc_perm *isp, int access) |
3282 | { |
3283 | struct smack_known *msp = smack_of_ipc(isp); |
3284 | struct smk_audit_info ad; |
3285 | int rc; |
3286 | |
3287 | #ifdef CONFIG_AUDIT |
3288 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_IPC); |
3289 | ad.a.u.ipc_id = isp->id; |
3290 | #endif |
3291 | rc = smk_curacc(msp, access, &ad); |
3292 | rc = smk_bu_current(note: "msq" , oskp: msp, mode: access, rc); |
3293 | return rc; |
3294 | } |
3295 | |
3296 | /** |
3297 | * smack_msg_queue_associate - Smack access check for msg_queue |
3298 | * @isp: the object |
3299 | * @msqflg: access requested |
3300 | * |
3301 | * Returns 0 if current has the requested access, error code otherwise |
3302 | */ |
3303 | static int smack_msg_queue_associate(struct kern_ipc_perm *isp, int msqflg) |
3304 | { |
3305 | int may; |
3306 | |
3307 | may = smack_flags_to_may(flags: msqflg); |
3308 | return smk_curacc_msq(isp, access: may); |
3309 | } |
3310 | |
3311 | /** |
3312 | * smack_msg_queue_msgctl - Smack access check for msg_queue |
3313 | * @isp: the object |
3314 | * @cmd: what it wants to do |
3315 | * |
3316 | * Returns 0 if current has the requested access, error code otherwise |
3317 | */ |
3318 | static int smack_msg_queue_msgctl(struct kern_ipc_perm *isp, int cmd) |
3319 | { |
3320 | int may; |
3321 | |
3322 | switch (cmd) { |
3323 | case IPC_STAT: |
3324 | case MSG_STAT: |
3325 | case MSG_STAT_ANY: |
3326 | may = MAY_READ; |
3327 | break; |
3328 | case IPC_SET: |
3329 | case IPC_RMID: |
3330 | may = MAY_READWRITE; |
3331 | break; |
3332 | case IPC_INFO: |
3333 | case MSG_INFO: |
3334 | /* |
3335 | * System level information |
3336 | */ |
3337 | return 0; |
3338 | default: |
3339 | return -EINVAL; |
3340 | } |
3341 | |
3342 | return smk_curacc_msq(isp, access: may); |
3343 | } |
3344 | |
3345 | /** |
3346 | * smack_msg_queue_msgsnd - Smack access check for msg_queue |
3347 | * @isp: the object |
3348 | * @msg: unused |
3349 | * @msqflg: access requested |
3350 | * |
3351 | * Returns 0 if current has the requested access, error code otherwise |
3352 | */ |
3353 | static int smack_msg_queue_msgsnd(struct kern_ipc_perm *isp, struct msg_msg *msg, |
3354 | int msqflg) |
3355 | { |
3356 | int may; |
3357 | |
3358 | may = smack_flags_to_may(flags: msqflg); |
3359 | return smk_curacc_msq(isp, access: may); |
3360 | } |
3361 | |
3362 | /** |
3363 | * smack_msg_queue_msgrcv - Smack access check for msg_queue |
3364 | * @isp: the object |
3365 | * @msg: unused |
3366 | * @target: unused |
3367 | * @type: unused |
3368 | * @mode: unused |
3369 | * |
3370 | * Returns 0 if current has read and write access, error code otherwise |
3371 | */ |
3372 | static int smack_msg_queue_msgrcv(struct kern_ipc_perm *isp, |
3373 | struct msg_msg *msg, |
3374 | struct task_struct *target, long type, |
3375 | int mode) |
3376 | { |
3377 | return smk_curacc_msq(isp, MAY_READWRITE); |
3378 | } |
3379 | |
3380 | /** |
3381 | * smack_ipc_permission - Smack access for ipc_permission() |
3382 | * @ipp: the object permissions |
3383 | * @flag: access requested |
3384 | * |
3385 | * Returns 0 if current has read and write access, error code otherwise |
3386 | */ |
3387 | static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag) |
3388 | { |
3389 | struct smack_known **blob = smack_ipc(ipc: ipp); |
3390 | struct smack_known *iskp = *blob; |
3391 | int may = smack_flags_to_may(flags: flag); |
3392 | struct smk_audit_info ad; |
3393 | int rc; |
3394 | |
3395 | #ifdef CONFIG_AUDIT |
3396 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_IPC); |
3397 | ad.a.u.ipc_id = ipp->id; |
3398 | #endif |
3399 | rc = smk_curacc(iskp, may, &ad); |
3400 | rc = smk_bu_current(note: "svipc" , oskp: iskp, mode: may, rc); |
3401 | return rc; |
3402 | } |
3403 | |
3404 | /** |
3405 | * smack_ipc_getsecid - Extract smack security id |
3406 | * @ipp: the object permissions |
3407 | * @secid: where result will be saved |
3408 | */ |
3409 | static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid) |
3410 | { |
3411 | struct smack_known **blob = smack_ipc(ipc: ipp); |
3412 | struct smack_known *iskp = *blob; |
3413 | |
3414 | *secid = iskp->smk_secid; |
3415 | } |
3416 | |
3417 | /** |
3418 | * smack_d_instantiate - Make sure the blob is correct on an inode |
3419 | * @opt_dentry: dentry where inode will be attached |
3420 | * @inode: the object |
3421 | * |
3422 | * Set the inode's security blob if it hasn't been done already. |
3423 | */ |
3424 | static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) |
3425 | { |
3426 | struct super_block *sbp; |
3427 | struct superblock_smack *sbsp; |
3428 | struct inode_smack *isp; |
3429 | struct smack_known *skp; |
3430 | struct smack_known *ckp = smk_of_current(); |
3431 | struct smack_known *final; |
3432 | char trattr[TRANS_TRUE_SIZE]; |
3433 | int transflag = 0; |
3434 | int rc; |
3435 | struct dentry *dp; |
3436 | |
3437 | if (inode == NULL) |
3438 | return; |
3439 | |
3440 | isp = smack_inode(inode); |
3441 | |
3442 | /* |
3443 | * If the inode is already instantiated |
3444 | * take the quick way out |
3445 | */ |
3446 | if (isp->smk_flags & SMK_INODE_INSTANT) |
3447 | return; |
3448 | |
3449 | sbp = inode->i_sb; |
3450 | sbsp = smack_superblock(superblock: sbp); |
3451 | /* |
3452 | * We're going to use the superblock default label |
3453 | * if there's no label on the file. |
3454 | */ |
3455 | final = sbsp->smk_default; |
3456 | |
3457 | /* |
3458 | * If this is the root inode the superblock |
3459 | * may be in the process of initialization. |
3460 | * If that is the case use the root value out |
3461 | * of the superblock. |
3462 | */ |
3463 | if (opt_dentry->d_parent == opt_dentry) { |
3464 | switch (sbp->s_magic) { |
3465 | case CGROUP_SUPER_MAGIC: |
3466 | case CGROUP2_SUPER_MAGIC: |
3467 | /* |
3468 | * The cgroup filesystem is never mounted, |
3469 | * so there's no opportunity to set the mount |
3470 | * options. |
3471 | */ |
3472 | sbsp->smk_root = &smack_known_star; |
3473 | sbsp->smk_default = &smack_known_star; |
3474 | isp->smk_inode = sbsp->smk_root; |
3475 | break; |
3476 | case TMPFS_MAGIC: |
3477 | /* |
3478 | * What about shmem/tmpfs anonymous files with dentry |
3479 | * obtained from d_alloc_pseudo()? |
3480 | */ |
3481 | isp->smk_inode = smk_of_current(); |
3482 | break; |
3483 | case PIPEFS_MAGIC: |
3484 | isp->smk_inode = smk_of_current(); |
3485 | break; |
3486 | case SOCKFS_MAGIC: |
3487 | /* |
3488 | * Socket access is controlled by the socket |
3489 | * structures associated with the task involved. |
3490 | */ |
3491 | isp->smk_inode = &smack_known_star; |
3492 | break; |
3493 | default: |
3494 | isp->smk_inode = sbsp->smk_root; |
3495 | break; |
3496 | } |
3497 | isp->smk_flags |= SMK_INODE_INSTANT; |
3498 | return; |
3499 | } |
3500 | |
3501 | /* |
3502 | * This is pretty hackish. |
3503 | * Casey says that we shouldn't have to do |
3504 | * file system specific code, but it does help |
3505 | * with keeping it simple. |
3506 | */ |
3507 | switch (sbp->s_magic) { |
3508 | case SMACK_MAGIC: |
3509 | case CGROUP_SUPER_MAGIC: |
3510 | case CGROUP2_SUPER_MAGIC: |
3511 | /* |
3512 | * Casey says that it's a little embarrassing |
3513 | * that the smack file system doesn't do |
3514 | * extended attributes. |
3515 | * |
3516 | * Cgroupfs is special |
3517 | */ |
3518 | final = &smack_known_star; |
3519 | break; |
3520 | case DEVPTS_SUPER_MAGIC: |
3521 | /* |
3522 | * devpts seems content with the label of the task. |
3523 | * Programs that change smack have to treat the |
3524 | * pty with respect. |
3525 | */ |
3526 | final = ckp; |
3527 | break; |
3528 | case PROC_SUPER_MAGIC: |
3529 | /* |
3530 | * Casey says procfs appears not to care. |
3531 | * The superblock default suffices. |
3532 | */ |
3533 | break; |
3534 | case TMPFS_MAGIC: |
3535 | /* |
3536 | * Device labels should come from the filesystem, |
3537 | * but watch out, because they're volitile, |
3538 | * getting recreated on every reboot. |
3539 | */ |
3540 | final = &smack_known_star; |
3541 | /* |
3542 | * If a smack value has been set we want to use it, |
3543 | * but since tmpfs isn't giving us the opportunity |
3544 | * to set mount options simulate setting the |
3545 | * superblock default. |
3546 | */ |
3547 | fallthrough; |
3548 | default: |
3549 | /* |
3550 | * This isn't an understood special case. |
3551 | * Get the value from the xattr. |
3552 | */ |
3553 | |
3554 | /* |
3555 | * UNIX domain sockets use lower level socket data. |
3556 | */ |
3557 | if (S_ISSOCK(inode->i_mode)) { |
3558 | final = &smack_known_star; |
3559 | break; |
3560 | } |
3561 | /* |
3562 | * No xattr support means, alas, no SMACK label. |
3563 | * Use the aforeapplied default. |
3564 | * It would be curious if the label of the task |
3565 | * does not match that assigned. |
3566 | */ |
3567 | if (!(inode->i_opflags & IOP_XATTR)) |
3568 | break; |
3569 | /* |
3570 | * Get the dentry for xattr. |
3571 | */ |
3572 | dp = dget(dentry: opt_dentry); |
3573 | skp = smk_fetch(XATTR_NAME_SMACK, ip: inode, dp); |
3574 | if (!IS_ERR_OR_NULL(ptr: skp)) |
3575 | final = skp; |
3576 | |
3577 | /* |
3578 | * Transmuting directory |
3579 | */ |
3580 | if (S_ISDIR(inode->i_mode)) { |
3581 | /* |
3582 | * If this is a new directory and the label was |
3583 | * transmuted when the inode was initialized |
3584 | * set the transmute attribute on the directory |
3585 | * and mark the inode. |
3586 | * |
3587 | * If there is a transmute attribute on the |
3588 | * directory mark the inode. |
3589 | */ |
3590 | rc = __vfs_getxattr(dp, inode, |
3591 | XATTR_NAME_SMACKTRANSMUTE, trattr, |
3592 | TRANS_TRUE_SIZE); |
3593 | if (rc >= 0 && strncmp(trattr, TRANS_TRUE, |
3594 | TRANS_TRUE_SIZE) != 0) |
3595 | rc = -EINVAL; |
3596 | if (rc >= 0) |
3597 | transflag = SMK_INODE_TRANSMUTE; |
3598 | } |
3599 | /* |
3600 | * Don't let the exec or mmap label be "*" or "@". |
3601 | */ |
3602 | skp = smk_fetch(XATTR_NAME_SMACKEXEC, ip: inode, dp); |
3603 | if (IS_ERR(ptr: skp) || skp == &smack_known_star || |
3604 | skp == &smack_known_web) |
3605 | skp = NULL; |
3606 | isp->smk_task = skp; |
3607 | |
3608 | skp = smk_fetch(XATTR_NAME_SMACKMMAP, ip: inode, dp); |
3609 | if (IS_ERR(ptr: skp) || skp == &smack_known_star || |
3610 | skp == &smack_known_web) |
3611 | skp = NULL; |
3612 | isp->smk_mmap = skp; |
3613 | |
3614 | dput(dp); |
3615 | break; |
3616 | } |
3617 | |
3618 | if (final == NULL) |
3619 | isp->smk_inode = ckp; |
3620 | else |
3621 | isp->smk_inode = final; |
3622 | |
3623 | isp->smk_flags |= (SMK_INODE_INSTANT | transflag); |
3624 | |
3625 | return; |
3626 | } |
3627 | |
3628 | /** |
3629 | * smack_getprocattr - Smack process attribute access |
3630 | * @p: the object task |
3631 | * @name: the name of the attribute in /proc/.../attr |
3632 | * @value: where to put the result |
3633 | * |
3634 | * Places a copy of the task Smack into value |
3635 | * |
3636 | * Returns the length of the smack label or an error code |
3637 | */ |
3638 | static int smack_getprocattr(struct task_struct *p, const char *name, char **value) |
3639 | { |
3640 | struct smack_known *skp = smk_of_task_struct_obj(t: p); |
3641 | char *cp; |
3642 | int slen; |
3643 | |
3644 | if (strcmp(name, "current" ) != 0) |
3645 | return -EINVAL; |
3646 | |
3647 | cp = kstrdup(s: skp->smk_known, GFP_KERNEL); |
3648 | if (cp == NULL) |
3649 | return -ENOMEM; |
3650 | |
3651 | slen = strlen(cp); |
3652 | *value = cp; |
3653 | return slen; |
3654 | } |
3655 | |
3656 | /** |
3657 | * smack_setprocattr - Smack process attribute setting |
3658 | * @name: the name of the attribute in /proc/.../attr |
3659 | * @value: the value to set |
3660 | * @size: the size of the value |
3661 | * |
3662 | * Sets the Smack value of the task. Only setting self |
3663 | * is permitted and only with privilege |
3664 | * |
3665 | * Returns the length of the smack label or an error code |
3666 | */ |
3667 | static int smack_setprocattr(const char *name, void *value, size_t size) |
3668 | { |
3669 | struct task_smack *tsp = smack_cred(current_cred()); |
3670 | struct cred *new; |
3671 | struct smack_known *skp; |
3672 | struct smack_known_list_elem *sklep; |
3673 | int rc; |
3674 | |
3675 | if (!smack_privileged(CAP_MAC_ADMIN) && list_empty(head: &tsp->smk_relabel)) |
3676 | return -EPERM; |
3677 | |
3678 | if (value == NULL || size == 0 || size >= SMK_LONGLABEL) |
3679 | return -EINVAL; |
3680 | |
3681 | if (strcmp(name, "current" ) != 0) |
3682 | return -EINVAL; |
3683 | |
3684 | skp = smk_import_entry(value, size); |
3685 | if (IS_ERR(ptr: skp)) |
3686 | return PTR_ERR(ptr: skp); |
3687 | |
3688 | /* |
3689 | * No process is ever allowed the web ("@") label |
3690 | * and the star ("*") label. |
3691 | */ |
3692 | if (skp == &smack_known_web || skp == &smack_known_star) |
3693 | return -EINVAL; |
3694 | |
3695 | if (!smack_privileged(CAP_MAC_ADMIN)) { |
3696 | rc = -EPERM; |
3697 | list_for_each_entry(sklep, &tsp->smk_relabel, list) |
3698 | if (sklep->smk_label == skp) { |
3699 | rc = 0; |
3700 | break; |
3701 | } |
3702 | if (rc) |
3703 | return rc; |
3704 | } |
3705 | |
3706 | new = prepare_creds(); |
3707 | if (new == NULL) |
3708 | return -ENOMEM; |
3709 | |
3710 | tsp = smack_cred(cred: new); |
3711 | tsp->smk_task = skp; |
3712 | /* |
3713 | * process can change its label only once |
3714 | */ |
3715 | smk_destroy_label_list(list: &tsp->smk_relabel); |
3716 | |
3717 | commit_creds(new); |
3718 | return size; |
3719 | } |
3720 | |
3721 | /** |
3722 | * smack_unix_stream_connect - Smack access on UDS |
3723 | * @sock: one sock |
3724 | * @other: the other sock |
3725 | * @newsk: unused |
3726 | * |
3727 | * Return 0 if a subject with the smack of sock could access |
3728 | * an object with the smack of other, otherwise an error code |
3729 | */ |
3730 | static int smack_unix_stream_connect(struct sock *sock, |
3731 | struct sock *other, struct sock *newsk) |
3732 | { |
3733 | struct smack_known *skp; |
3734 | struct smack_known *okp; |
3735 | struct socket_smack *ssp = sock->sk_security; |
3736 | struct socket_smack *osp = other->sk_security; |
3737 | struct socket_smack *nsp = newsk->sk_security; |
3738 | struct smk_audit_info ad; |
3739 | int rc = 0; |
3740 | #ifdef CONFIG_AUDIT |
3741 | struct lsm_network_audit net; |
3742 | #endif |
3743 | |
3744 | if (!smack_privileged(CAP_MAC_OVERRIDE)) { |
3745 | skp = ssp->smk_out; |
3746 | okp = osp->smk_in; |
3747 | #ifdef CONFIG_AUDIT |
3748 | smk_ad_init_net(a: &ad, func: __func__, LSM_AUDIT_DATA_NET, net: &net); |
3749 | smk_ad_setfield_u_net_sk(a: &ad, sk: other); |
3750 | #endif |
3751 | rc = smk_access(skp, okp, MAY_WRITE, &ad); |
3752 | rc = smk_bu_note(note: "UDS connect" , sskp: skp, oskp: okp, MAY_WRITE, rc); |
3753 | if (rc == 0) { |
3754 | okp = osp->smk_out; |
3755 | skp = ssp->smk_in; |
3756 | rc = smk_access(okp, skp, MAY_WRITE, &ad); |
3757 | rc = smk_bu_note(note: "UDS connect" , sskp: okp, oskp: skp, |
3758 | MAY_WRITE, rc); |
3759 | } |
3760 | } |
3761 | |
3762 | /* |
3763 | * Cross reference the peer labels for SO_PEERSEC. |
3764 | */ |
3765 | if (rc == 0) { |
3766 | nsp->smk_packet = ssp->smk_out; |
3767 | ssp->smk_packet = osp->smk_out; |
3768 | } |
3769 | |
3770 | return rc; |
3771 | } |
3772 | |
3773 | /** |
3774 | * smack_unix_may_send - Smack access on UDS |
3775 | * @sock: one socket |
3776 | * @other: the other socket |
3777 | * |
3778 | * Return 0 if a subject with the smack of sock could access |
3779 | * an object with the smack of other, otherwise an error code |
3780 | */ |
3781 | static int smack_unix_may_send(struct socket *sock, struct socket *other) |
3782 | { |
3783 | struct socket_smack *ssp = sock->sk->sk_security; |
3784 | struct socket_smack *osp = other->sk->sk_security; |
3785 | struct smk_audit_info ad; |
3786 | int rc; |
3787 | |
3788 | #ifdef CONFIG_AUDIT |
3789 | struct lsm_network_audit net; |
3790 | |
3791 | smk_ad_init_net(a: &ad, func: __func__, LSM_AUDIT_DATA_NET, net: &net); |
3792 | smk_ad_setfield_u_net_sk(a: &ad, sk: other->sk); |
3793 | #endif |
3794 | |
3795 | if (smack_privileged(CAP_MAC_OVERRIDE)) |
3796 | return 0; |
3797 | |
3798 | rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad); |
3799 | rc = smk_bu_note(note: "UDS send" , sskp: ssp->smk_out, oskp: osp->smk_in, MAY_WRITE, rc); |
3800 | return rc; |
3801 | } |
3802 | |
3803 | /** |
3804 | * smack_socket_sendmsg - Smack check based on destination host |
3805 | * @sock: the socket |
3806 | * @msg: the message |
3807 | * @size: the size of the message |
3808 | * |
3809 | * Return 0 if the current subject can write to the destination host. |
3810 | * For IPv4 this is only a question if the destination is a single label host. |
3811 | * For IPv6 this is a check against the label of the port. |
3812 | */ |
3813 | static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg, |
3814 | int size) |
3815 | { |
3816 | struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name; |
3817 | #if IS_ENABLED(CONFIG_IPV6) |
3818 | struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name; |
3819 | #endif |
3820 | #ifdef SMACK_IPV6_SECMARK_LABELING |
3821 | struct socket_smack *ssp = sock->sk->sk_security; |
3822 | struct smack_known *rsp; |
3823 | #endif |
3824 | int rc = 0; |
3825 | |
3826 | /* |
3827 | * Perfectly reasonable for this to be NULL |
3828 | */ |
3829 | if (sip == NULL) |
3830 | return 0; |
3831 | |
3832 | switch (sock->sk->sk_family) { |
3833 | case AF_INET: |
3834 | if (msg->msg_namelen < sizeof(struct sockaddr_in) || |
3835 | sip->sin_family != AF_INET) |
3836 | return -EINVAL; |
3837 | rc = smk_ipv4_check(sk: sock->sk, sap: sip); |
3838 | break; |
3839 | #if IS_ENABLED(CONFIG_IPV6) |
3840 | case AF_INET6: |
3841 | if (msg->msg_namelen < SIN6_LEN_RFC2133 || |
3842 | sap->sin6_family != AF_INET6) |
3843 | return -EINVAL; |
3844 | #ifdef SMACK_IPV6_SECMARK_LABELING |
3845 | rsp = smack_ipv6host_label(sip: sap); |
3846 | if (rsp != NULL) |
3847 | rc = smk_ipv6_check(subject: ssp->smk_out, object: rsp, address: sap, |
3848 | SMK_CONNECTING); |
3849 | #endif |
3850 | #ifdef SMACK_IPV6_PORT_LABELING |
3851 | rc = smk_ipv6_port_check(sock->sk, sap, SMK_SENDING); |
3852 | #endif |
3853 | #endif /* IS_ENABLED(CONFIG_IPV6) */ |
3854 | break; |
3855 | } |
3856 | return rc; |
3857 | } |
3858 | |
3859 | /** |
3860 | * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack |
3861 | * @sap: netlabel secattr |
3862 | * @ssp: socket security information |
3863 | * |
3864 | * Returns a pointer to a Smack label entry found on the label list. |
3865 | */ |
3866 | static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap, |
3867 | struct socket_smack *ssp) |
3868 | { |
3869 | struct smack_known *skp; |
3870 | int found = 0; |
3871 | int acat; |
3872 | int kcat; |
3873 | |
3874 | /* |
3875 | * Netlabel found it in the cache. |
3876 | */ |
3877 | if ((sap->flags & NETLBL_SECATTR_CACHE) != 0) |
3878 | return (struct smack_known *)sap->cache->data; |
3879 | |
3880 | if ((sap->flags & NETLBL_SECATTR_SECID) != 0) |
3881 | /* |
3882 | * Looks like a fallback, which gives us a secid. |
3883 | */ |
3884 | return smack_from_secid(sap->attr.secid); |
3885 | |
3886 | if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) { |
3887 | /* |
3888 | * Looks like a CIPSO packet. |
3889 | * If there are flags but no level netlabel isn't |
3890 | * behaving the way we expect it to. |
3891 | * |
3892 | * Look it up in the label table |
3893 | * Without guidance regarding the smack value |
3894 | * for the packet fall back on the network |
3895 | * ambient value. |
3896 | */ |
3897 | rcu_read_lock(); |
3898 | list_for_each_entry_rcu(skp, &smack_known_list, list) { |
3899 | if (sap->attr.mls.lvl != skp->smk_netlabel.attr.mls.lvl) |
3900 | continue; |
3901 | /* |
3902 | * Compare the catsets. Use the netlbl APIs. |
3903 | */ |
3904 | if ((sap->flags & NETLBL_SECATTR_MLS_CAT) == 0) { |
3905 | if ((skp->smk_netlabel.flags & |
3906 | NETLBL_SECATTR_MLS_CAT) == 0) |
3907 | found = 1; |
3908 | break; |
3909 | } |
3910 | for (acat = -1, kcat = -1; acat == kcat; ) { |
3911 | acat = netlbl_catmap_walk(catmap: sap->attr.mls.cat, |
3912 | offset: acat + 1); |
3913 | kcat = netlbl_catmap_walk( |
3914 | catmap: skp->smk_netlabel.attr.mls.cat, |
3915 | offset: kcat + 1); |
3916 | if (acat < 0 || kcat < 0) |
3917 | break; |
3918 | } |
3919 | if (acat == kcat) { |
3920 | found = 1; |
3921 | break; |
3922 | } |
3923 | } |
3924 | rcu_read_unlock(); |
3925 | |
3926 | if (found) |
3927 | return skp; |
3928 | |
3929 | if (ssp != NULL && ssp->smk_in == &smack_known_star) |
3930 | return &smack_known_web; |
3931 | return &smack_known_star; |
3932 | } |
3933 | /* |
3934 | * Without guidance regarding the smack value |
3935 | * for the packet fall back on the network |
3936 | * ambient value. |
3937 | */ |
3938 | return smack_net_ambient; |
3939 | } |
3940 | |
3941 | #if IS_ENABLED(CONFIG_IPV6) |
3942 | static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip) |
3943 | { |
3944 | u8 nexthdr; |
3945 | int offset; |
3946 | int proto = -EINVAL; |
3947 | struct ipv6hdr _ipv6h; |
3948 | struct ipv6hdr *ip6; |
3949 | __be16 frag_off; |
3950 | struct tcphdr _tcph, *th; |
3951 | struct udphdr _udph, *uh; |
3952 | struct dccp_hdr _dccph, *dh; |
3953 | |
3954 | sip->sin6_port = 0; |
3955 | |
3956 | offset = skb_network_offset(skb); |
3957 | ip6 = skb_header_pointer(skb, offset, len: sizeof(_ipv6h), buffer: &_ipv6h); |
3958 | if (ip6 == NULL) |
3959 | return -EINVAL; |
3960 | sip->sin6_addr = ip6->saddr; |
3961 | |
3962 | nexthdr = ip6->nexthdr; |
3963 | offset += sizeof(_ipv6h); |
3964 | offset = ipv6_skip_exthdr(skb, start: offset, nexthdrp: &nexthdr, frag_offp: &frag_off); |
3965 | if (offset < 0) |
3966 | return -EINVAL; |
3967 | |
3968 | proto = nexthdr; |
3969 | switch (proto) { |
3970 | case IPPROTO_TCP: |
3971 | th = skb_header_pointer(skb, offset, len: sizeof(_tcph), buffer: &_tcph); |
3972 | if (th != NULL) |
3973 | sip->sin6_port = th->source; |
3974 | break; |
3975 | case IPPROTO_UDP: |
3976 | case IPPROTO_UDPLITE: |
3977 | uh = skb_header_pointer(skb, offset, len: sizeof(_udph), buffer: &_udph); |
3978 | if (uh != NULL) |
3979 | sip->sin6_port = uh->source; |
3980 | break; |
3981 | case IPPROTO_DCCP: |
3982 | dh = skb_header_pointer(skb, offset, len: sizeof(_dccph), buffer: &_dccph); |
3983 | if (dh != NULL) |
3984 | sip->sin6_port = dh->dccph_sport; |
3985 | break; |
3986 | } |
3987 | return proto; |
3988 | } |
3989 | #endif /* CONFIG_IPV6 */ |
3990 | |
3991 | /** |
3992 | * smack_from_skb - Smack data from the secmark in an skb |
3993 | * @skb: packet |
3994 | * |
3995 | * Returns smack_known of the secmark or NULL if that won't work. |
3996 | */ |
3997 | #ifdef CONFIG_NETWORK_SECMARK |
3998 | static struct smack_known *smack_from_skb(struct sk_buff *skb) |
3999 | { |
4000 | if (skb == NULL || skb->secmark == 0) |
4001 | return NULL; |
4002 | |
4003 | return smack_from_secid(skb->secmark); |
4004 | } |
4005 | #else |
4006 | static inline struct smack_known *smack_from_skb(struct sk_buff *skb) |
4007 | { |
4008 | return NULL; |
4009 | } |
4010 | #endif |
4011 | |
4012 | /** |
4013 | * smack_from_netlbl - Smack data from the IP options in an skb |
4014 | * @sk: socket data came in on |
4015 | * @family: address family |
4016 | * @skb: packet |
4017 | * |
4018 | * Find the Smack label in the IP options. If it hasn't been |
4019 | * added to the netlabel cache, add it here. |
4020 | * |
4021 | * Returns smack_known of the IP options or NULL if that won't work. |
4022 | */ |
4023 | static struct smack_known *smack_from_netlbl(const struct sock *sk, u16 family, |
4024 | struct sk_buff *skb) |
4025 | { |
4026 | struct netlbl_lsm_secattr secattr; |
4027 | struct socket_smack *ssp = NULL; |
4028 | struct smack_known *skp = NULL; |
4029 | |
4030 | netlbl_secattr_init(secattr: &secattr); |
4031 | |
4032 | if (sk) |
4033 | ssp = sk->sk_security; |
4034 | |
4035 | if (netlbl_skbuff_getattr(skb, family, secattr: &secattr) == 0) { |
4036 | skp = smack_from_secattr(sap: &secattr, ssp); |
4037 | if (secattr.flags & NETLBL_SECATTR_CACHEABLE) |
4038 | netlbl_cache_add(skb, family, secattr: &skp->smk_netlabel); |
4039 | } |
4040 | |
4041 | netlbl_secattr_destroy(secattr: &secattr); |
4042 | |
4043 | return skp; |
4044 | } |
4045 | |
4046 | /** |
4047 | * smack_socket_sock_rcv_skb - Smack packet delivery access check |
4048 | * @sk: socket |
4049 | * @skb: packet |
4050 | * |
4051 | * Returns 0 if the packet should be delivered, an error code otherwise |
4052 | */ |
4053 | static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) |
4054 | { |
4055 | struct socket_smack *ssp = sk->sk_security; |
4056 | struct smack_known *skp = NULL; |
4057 | int rc = 0; |
4058 | struct smk_audit_info ad; |
4059 | u16 family = sk->sk_family; |
4060 | #ifdef CONFIG_AUDIT |
4061 | struct lsm_network_audit net; |
4062 | #endif |
4063 | #if IS_ENABLED(CONFIG_IPV6) |
4064 | struct sockaddr_in6 sadd; |
4065 | int proto; |
4066 | |
4067 | if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) |
4068 | family = PF_INET; |
4069 | #endif /* CONFIG_IPV6 */ |
4070 | |
4071 | switch (family) { |
4072 | case PF_INET: |
4073 | /* |
4074 | * If there is a secmark use it rather than the CIPSO label. |
4075 | * If there is no secmark fall back to CIPSO. |
4076 | * The secmark is assumed to reflect policy better. |
4077 | */ |
4078 | skp = smack_from_skb(skb); |
4079 | if (skp == NULL) { |
4080 | skp = smack_from_netlbl(sk, family, skb); |
4081 | if (skp == NULL) |
4082 | skp = smack_net_ambient; |
4083 | } |
4084 | |
4085 | #ifdef CONFIG_AUDIT |
4086 | smk_ad_init_net(a: &ad, func: __func__, LSM_AUDIT_DATA_NET, net: &net); |
4087 | ad.a.u.net->family = family; |
4088 | ad.a.u.net->netif = skb->skb_iif; |
4089 | ipv4_skb_to_auditdata(skb, ad: &ad.a, NULL); |
4090 | #endif |
4091 | /* |
4092 | * Receiving a packet requires that the other end |
4093 | * be able to write here. Read access is not required. |
4094 | * This is the simplist possible security model |
4095 | * for networking. |
4096 | */ |
4097 | rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad); |
4098 | rc = smk_bu_note(note: "IPv4 delivery" , sskp: skp, oskp: ssp->smk_in, |
4099 | MAY_WRITE, rc); |
4100 | if (rc != 0) |
4101 | netlbl_skbuff_err(skb, family, error: rc, gateway: 0); |
4102 | break; |
4103 | #if IS_ENABLED(CONFIG_IPV6) |
4104 | case PF_INET6: |
4105 | proto = smk_skb_to_addr_ipv6(skb, sip: &sadd); |
4106 | if (proto != IPPROTO_UDP && proto != IPPROTO_UDPLITE && |
4107 | proto != IPPROTO_TCP && proto != IPPROTO_DCCP) |
4108 | break; |
4109 | #ifdef SMACK_IPV6_SECMARK_LABELING |
4110 | skp = smack_from_skb(skb); |
4111 | if (skp == NULL) { |
4112 | if (smk_ipv6_localhost(sip: &sadd)) |
4113 | break; |
4114 | skp = smack_ipv6host_label(sip: &sadd); |
4115 | if (skp == NULL) |
4116 | skp = smack_net_ambient; |
4117 | } |
4118 | #ifdef CONFIG_AUDIT |
4119 | smk_ad_init_net(a: &ad, func: __func__, LSM_AUDIT_DATA_NET, net: &net); |
4120 | ad.a.u.net->family = family; |
4121 | ad.a.u.net->netif = skb->skb_iif; |
4122 | ipv6_skb_to_auditdata(skb, ad: &ad.a, NULL); |
4123 | #endif /* CONFIG_AUDIT */ |
4124 | rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad); |
4125 | rc = smk_bu_note(note: "IPv6 delivery" , sskp: skp, oskp: ssp->smk_in, |
4126 | MAY_WRITE, rc); |
4127 | #endif /* SMACK_IPV6_SECMARK_LABELING */ |
4128 | #ifdef SMACK_IPV6_PORT_LABELING |
4129 | rc = smk_ipv6_port_check(sk, &sadd, SMK_RECEIVING); |
4130 | #endif /* SMACK_IPV6_PORT_LABELING */ |
4131 | if (rc != 0) |
4132 | icmpv6_send(skb, ICMPV6_DEST_UNREACH, |
4133 | ICMPV6_ADM_PROHIBITED, info: 0); |
4134 | break; |
4135 | #endif /* CONFIG_IPV6 */ |
4136 | } |
4137 | |
4138 | return rc; |
4139 | } |
4140 | |
4141 | /** |
4142 | * smack_socket_getpeersec_stream - pull in packet label |
4143 | * @sock: the socket |
4144 | * @optval: user's destination |
4145 | * @optlen: size thereof |
4146 | * @len: max thereof |
4147 | * |
4148 | * returns zero on success, an error code otherwise |
4149 | */ |
4150 | static int smack_socket_getpeersec_stream(struct socket *sock, |
4151 | sockptr_t optval, sockptr_t optlen, |
4152 | unsigned int len) |
4153 | { |
4154 | struct socket_smack *ssp; |
4155 | char *rcp = "" ; |
4156 | u32 slen = 1; |
4157 | int rc = 0; |
4158 | |
4159 | ssp = sock->sk->sk_security; |
4160 | if (ssp->smk_packet != NULL) { |
4161 | rcp = ssp->smk_packet->smk_known; |
4162 | slen = strlen(rcp) + 1; |
4163 | } |
4164 | if (slen > len) { |
4165 | rc = -ERANGE; |
4166 | goto out_len; |
4167 | } |
4168 | |
4169 | if (copy_to_sockptr(dst: optval, src: rcp, size: slen)) |
4170 | rc = -EFAULT; |
4171 | out_len: |
4172 | if (copy_to_sockptr(dst: optlen, src: &slen, size: sizeof(slen))) |
4173 | rc = -EFAULT; |
4174 | return rc; |
4175 | } |
4176 | |
4177 | |
4178 | /** |
4179 | * smack_socket_getpeersec_dgram - pull in packet label |
4180 | * @sock: the peer socket |
4181 | * @skb: packet data |
4182 | * @secid: pointer to where to put the secid of the packet |
4183 | * |
4184 | * Sets the netlabel socket state on sk from parent |
4185 | */ |
4186 | static int smack_socket_getpeersec_dgram(struct socket *sock, |
4187 | struct sk_buff *skb, u32 *secid) |
4188 | |
4189 | { |
4190 | struct socket_smack *ssp = NULL; |
4191 | struct smack_known *skp; |
4192 | struct sock *sk = NULL; |
4193 | int family = PF_UNSPEC; |
4194 | u32 s = 0; /* 0 is the invalid secid */ |
4195 | |
4196 | if (skb != NULL) { |
4197 | if (skb->protocol == htons(ETH_P_IP)) |
4198 | family = PF_INET; |
4199 | #if IS_ENABLED(CONFIG_IPV6) |
4200 | else if (skb->protocol == htons(ETH_P_IPV6)) |
4201 | family = PF_INET6; |
4202 | #endif /* CONFIG_IPV6 */ |
4203 | } |
4204 | if (family == PF_UNSPEC && sock != NULL) |
4205 | family = sock->sk->sk_family; |
4206 | |
4207 | switch (family) { |
4208 | case PF_UNIX: |
4209 | ssp = sock->sk->sk_security; |
4210 | s = ssp->smk_out->smk_secid; |
4211 | break; |
4212 | case PF_INET: |
4213 | skp = smack_from_skb(skb); |
4214 | if (skp) { |
4215 | s = skp->smk_secid; |
4216 | break; |
4217 | } |
4218 | /* |
4219 | * Translate what netlabel gave us. |
4220 | */ |
4221 | if (sock != NULL) |
4222 | sk = sock->sk; |
4223 | skp = smack_from_netlbl(sk, family, skb); |
4224 | if (skp != NULL) |
4225 | s = skp->smk_secid; |
4226 | break; |
4227 | case PF_INET6: |
4228 | #ifdef SMACK_IPV6_SECMARK_LABELING |
4229 | skp = smack_from_skb(skb); |
4230 | if (skp) |
4231 | s = skp->smk_secid; |
4232 | #endif |
4233 | break; |
4234 | } |
4235 | *secid = s; |
4236 | if (s == 0) |
4237 | return -EINVAL; |
4238 | return 0; |
4239 | } |
4240 | |
4241 | /** |
4242 | * smack_sock_graft - Initialize a newly created socket with an existing sock |
4243 | * @sk: child sock |
4244 | * @parent: parent socket |
4245 | * |
4246 | * Set the smk_{in,out} state of an existing sock based on the process that |
4247 | * is creating the new socket. |
4248 | */ |
4249 | static void smack_sock_graft(struct sock *sk, struct socket *parent) |
4250 | { |
4251 | struct socket_smack *ssp; |
4252 | struct smack_known *skp = smk_of_current(); |
4253 | |
4254 | if (sk == NULL || |
4255 | (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)) |
4256 | return; |
4257 | |
4258 | ssp = sk->sk_security; |
4259 | ssp->smk_in = skp; |
4260 | ssp->smk_out = skp; |
4261 | /* cssp->smk_packet is already set in smack_inet_csk_clone() */ |
4262 | } |
4263 | |
4264 | /** |
4265 | * smack_inet_conn_request - Smack access check on connect |
4266 | * @sk: socket involved |
4267 | * @skb: packet |
4268 | * @req: unused |
4269 | * |
4270 | * Returns 0 if a task with the packet label could write to |
4271 | * the socket, otherwise an error code |
4272 | */ |
4273 | static int smack_inet_conn_request(const struct sock *sk, struct sk_buff *skb, |
4274 | struct request_sock *req) |
4275 | { |
4276 | u16 family = sk->sk_family; |
4277 | struct smack_known *skp; |
4278 | struct socket_smack *ssp = sk->sk_security; |
4279 | struct sockaddr_in addr; |
4280 | struct iphdr *hdr; |
4281 | struct smack_known *hskp; |
4282 | int rc; |
4283 | struct smk_audit_info ad; |
4284 | #ifdef CONFIG_AUDIT |
4285 | struct lsm_network_audit net; |
4286 | #endif |
4287 | |
4288 | #if IS_ENABLED(CONFIG_IPV6) |
4289 | if (family == PF_INET6) { |
4290 | /* |
4291 | * Handle mapped IPv4 packets arriving |
4292 | * via IPv6 sockets. Don't set up netlabel |
4293 | * processing on IPv6. |
4294 | */ |
4295 | if (skb->protocol == htons(ETH_P_IP)) |
4296 | family = PF_INET; |
4297 | else |
4298 | return 0; |
4299 | } |
4300 | #endif /* CONFIG_IPV6 */ |
4301 | |
4302 | /* |
4303 | * If there is a secmark use it rather than the CIPSO label. |
4304 | * If there is no secmark fall back to CIPSO. |
4305 | * The secmark is assumed to reflect policy better. |
4306 | */ |
4307 | skp = smack_from_skb(skb); |
4308 | if (skp == NULL) { |
4309 | skp = smack_from_netlbl(sk, family, skb); |
4310 | if (skp == NULL) |
4311 | skp = &smack_known_huh; |
4312 | } |
4313 | |
4314 | #ifdef CONFIG_AUDIT |
4315 | smk_ad_init_net(a: &ad, func: __func__, LSM_AUDIT_DATA_NET, net: &net); |
4316 | ad.a.u.net->family = family; |
4317 | ad.a.u.net->netif = skb->skb_iif; |
4318 | ipv4_skb_to_auditdata(skb, ad: &ad.a, NULL); |
4319 | #endif |
4320 | /* |
4321 | * Receiving a packet requires that the other end be able to write |
4322 | * here. Read access is not required. |
4323 | */ |
4324 | rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad); |
4325 | rc = smk_bu_note(note: "IPv4 connect" , sskp: skp, oskp: ssp->smk_in, MAY_WRITE, rc); |
4326 | if (rc != 0) |
4327 | return rc; |
4328 | |
4329 | /* |
4330 | * Save the peer's label in the request_sock so we can later setup |
4331 | * smk_packet in the child socket so that SO_PEERCRED can report it. |
4332 | */ |
4333 | req->peer_secid = skp->smk_secid; |
4334 | |
4335 | /* |
4336 | * We need to decide if we want to label the incoming connection here |
4337 | * if we do we only need to label the request_sock and the stack will |
4338 | * propagate the wire-label to the sock when it is created. |
4339 | */ |
4340 | hdr = ip_hdr(skb); |
4341 | addr.sin_addr.s_addr = hdr->saddr; |
4342 | rcu_read_lock(); |
4343 | hskp = smack_ipv4host_label(sip: &addr); |
4344 | rcu_read_unlock(); |
4345 | |
4346 | if (hskp == NULL) |
4347 | rc = netlbl_req_setattr(req, secattr: &skp->smk_netlabel); |
4348 | else |
4349 | netlbl_req_delattr(req); |
4350 | |
4351 | return rc; |
4352 | } |
4353 | |
4354 | /** |
4355 | * smack_inet_csk_clone - Copy the connection information to the new socket |
4356 | * @sk: the new socket |
4357 | * @req: the connection's request_sock |
4358 | * |
4359 | * Transfer the connection's peer label to the newly created socket. |
4360 | */ |
4361 | static void smack_inet_csk_clone(struct sock *sk, |
4362 | const struct request_sock *req) |
4363 | { |
4364 | struct socket_smack *ssp = sk->sk_security; |
4365 | struct smack_known *skp; |
4366 | |
4367 | if (req->peer_secid != 0) { |
4368 | skp = smack_from_secid(req->peer_secid); |
4369 | ssp->smk_packet = skp; |
4370 | } else |
4371 | ssp->smk_packet = NULL; |
4372 | } |
4373 | |
4374 | /* |
4375 | * Key management security hooks |
4376 | * |
4377 | * Casey has not tested key support very heavily. |
4378 | * The permission check is most likely too restrictive. |
4379 | * If you care about keys please have a look. |
4380 | */ |
4381 | #ifdef CONFIG_KEYS |
4382 | |
4383 | /** |
4384 | * smack_key_alloc - Set the key security blob |
4385 | * @key: object |
4386 | * @cred: the credentials to use |
4387 | * @flags: unused |
4388 | * |
4389 | * No allocation required |
4390 | * |
4391 | * Returns 0 |
4392 | */ |
4393 | static int smack_key_alloc(struct key *key, const struct cred *cred, |
4394 | unsigned long flags) |
4395 | { |
4396 | struct smack_known *skp = smk_of_task(tsp: smack_cred(cred)); |
4397 | |
4398 | key->security = skp; |
4399 | return 0; |
4400 | } |
4401 | |
4402 | /** |
4403 | * smack_key_free - Clear the key security blob |
4404 | * @key: the object |
4405 | * |
4406 | * Clear the blob pointer |
4407 | */ |
4408 | static void smack_key_free(struct key *key) |
4409 | { |
4410 | key->security = NULL; |
4411 | } |
4412 | |
4413 | /** |
4414 | * smack_key_permission - Smack access on a key |
4415 | * @key_ref: gets to the object |
4416 | * @cred: the credentials to use |
4417 | * @need_perm: requested key permission |
4418 | * |
4419 | * Return 0 if the task has read and write to the object, |
4420 | * an error code otherwise |
4421 | */ |
4422 | static int smack_key_permission(key_ref_t key_ref, |
4423 | const struct cred *cred, |
4424 | enum key_need_perm need_perm) |
4425 | { |
4426 | struct key *keyp; |
4427 | struct smk_audit_info ad; |
4428 | struct smack_known *tkp = smk_of_task(tsp: smack_cred(cred)); |
4429 | int request = 0; |
4430 | int rc; |
4431 | |
4432 | /* |
4433 | * Validate requested permissions |
4434 | */ |
4435 | switch (need_perm) { |
4436 | case KEY_NEED_READ: |
4437 | case KEY_NEED_SEARCH: |
4438 | case KEY_NEED_VIEW: |
4439 | request |= MAY_READ; |
4440 | break; |
4441 | case KEY_NEED_WRITE: |
4442 | case KEY_NEED_LINK: |
4443 | case KEY_NEED_SETATTR: |
4444 | request |= MAY_WRITE; |
4445 | break; |
4446 | case KEY_NEED_UNSPECIFIED: |
4447 | case KEY_NEED_UNLINK: |
4448 | case KEY_SYSADMIN_OVERRIDE: |
4449 | case KEY_AUTHTOKEN_OVERRIDE: |
4450 | case KEY_DEFER_PERM_CHECK: |
4451 | return 0; |
4452 | default: |
4453 | return -EINVAL; |
4454 | } |
4455 | |
4456 | keyp = key_ref_to_ptr(key_ref); |
4457 | if (keyp == NULL) |
4458 | return -EINVAL; |
4459 | /* |
4460 | * If the key hasn't been initialized give it access so that |
4461 | * it may do so. |
4462 | */ |
4463 | if (keyp->security == NULL) |
4464 | return 0; |
4465 | /* |
4466 | * This should not occur |
4467 | */ |
4468 | if (tkp == NULL) |
4469 | return -EACCES; |
4470 | |
4471 | if (smack_privileged(CAP_MAC_OVERRIDE)) |
4472 | return 0; |
4473 | |
4474 | #ifdef CONFIG_AUDIT |
4475 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_KEY); |
4476 | ad.a.u.key_struct.key = keyp->serial; |
4477 | ad.a.u.key_struct.key_desc = keyp->description; |
4478 | #endif |
4479 | rc = smk_access(tkp, keyp->security, request, &ad); |
4480 | rc = smk_bu_note(note: "key access" , sskp: tkp, oskp: keyp->security, mode: request, rc); |
4481 | return rc; |
4482 | } |
4483 | |
4484 | /* |
4485 | * smack_key_getsecurity - Smack label tagging the key |
4486 | * @key points to the key to be queried |
4487 | * @_buffer points to a pointer that should be set to point to the |
4488 | * resulting string (if no label or an error occurs). |
4489 | * Return the length of the string (including terminating NUL) or -ve if |
4490 | * an error. |
4491 | * May also return 0 (and a NULL buffer pointer) if there is no label. |
4492 | */ |
4493 | static int smack_key_getsecurity(struct key *key, char **_buffer) |
4494 | { |
4495 | struct smack_known *skp = key->security; |
4496 | size_t length; |
4497 | char *copy; |
4498 | |
4499 | if (key->security == NULL) { |
4500 | *_buffer = NULL; |
4501 | return 0; |
4502 | } |
4503 | |
4504 | copy = kstrdup(s: skp->smk_known, GFP_KERNEL); |
4505 | if (copy == NULL) |
4506 | return -ENOMEM; |
4507 | length = strlen(copy) + 1; |
4508 | |
4509 | *_buffer = copy; |
4510 | return length; |
4511 | } |
4512 | |
4513 | |
4514 | #ifdef CONFIG_KEY_NOTIFICATIONS |
4515 | /** |
4516 | * smack_watch_key - Smack access to watch a key for notifications. |
4517 | * @key: The key to be watched |
4518 | * |
4519 | * Return 0 if the @watch->cred has permission to read from the key object and |
4520 | * an error otherwise. |
4521 | */ |
4522 | static int smack_watch_key(struct key *key) |
4523 | { |
4524 | struct smk_audit_info ad; |
4525 | struct smack_known *tkp = smk_of_current(); |
4526 | int rc; |
4527 | |
4528 | if (key == NULL) |
4529 | return -EINVAL; |
4530 | /* |
4531 | * If the key hasn't been initialized give it access so that |
4532 | * it may do so. |
4533 | */ |
4534 | if (key->security == NULL) |
4535 | return 0; |
4536 | /* |
4537 | * This should not occur |
4538 | */ |
4539 | if (tkp == NULL) |
4540 | return -EACCES; |
4541 | |
4542 | if (smack_privileged_cred(CAP_MAC_OVERRIDE, current_cred())) |
4543 | return 0; |
4544 | |
4545 | #ifdef CONFIG_AUDIT |
4546 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_KEY); |
4547 | ad.a.u.key_struct.key = key->serial; |
4548 | ad.a.u.key_struct.key_desc = key->description; |
4549 | #endif |
4550 | rc = smk_access(tkp, key->security, MAY_READ, &ad); |
4551 | rc = smk_bu_note(note: "key watch" , sskp: tkp, oskp: key->security, MAY_READ, rc); |
4552 | return rc; |
4553 | } |
4554 | #endif /* CONFIG_KEY_NOTIFICATIONS */ |
4555 | #endif /* CONFIG_KEYS */ |
4556 | |
4557 | #ifdef CONFIG_WATCH_QUEUE |
4558 | /** |
4559 | * smack_post_notification - Smack access to post a notification to a queue |
4560 | * @w_cred: The credentials of the watcher. |
4561 | * @cred: The credentials of the event source (may be NULL). |
4562 | * @n: The notification message to be posted. |
4563 | */ |
4564 | static int smack_post_notification(const struct cred *w_cred, |
4565 | const struct cred *cred, |
4566 | struct watch_notification *n) |
4567 | { |
4568 | struct smk_audit_info ad; |
4569 | struct smack_known *subj, *obj; |
4570 | int rc; |
4571 | |
4572 | /* Always let maintenance notifications through. */ |
4573 | if (n->type == WATCH_TYPE_META) |
4574 | return 0; |
4575 | |
4576 | if (!cred) |
4577 | return 0; |
4578 | subj = smk_of_task(tsp: smack_cred(cred)); |
4579 | obj = smk_of_task(tsp: smack_cred(cred: w_cred)); |
4580 | |
4581 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_NOTIFICATION); |
4582 | rc = smk_access(subj, obj, MAY_WRITE, &ad); |
4583 | rc = smk_bu_note(note: "notification" , sskp: subj, oskp: obj, MAY_WRITE, rc); |
4584 | return rc; |
4585 | } |
4586 | #endif /* CONFIG_WATCH_QUEUE */ |
4587 | |
4588 | /* |
4589 | * Smack Audit hooks |
4590 | * |
4591 | * Audit requires a unique representation of each Smack specific |
4592 | * rule. This unique representation is used to distinguish the |
4593 | * object to be audited from remaining kernel objects and also |
4594 | * works as a glue between the audit hooks. |
4595 | * |
4596 | * Since repository entries are added but never deleted, we'll use |
4597 | * the smack_known label address related to the given audit rule as |
4598 | * the needed unique representation. This also better fits the smack |
4599 | * model where nearly everything is a label. |
4600 | */ |
4601 | #ifdef CONFIG_AUDIT |
4602 | |
4603 | /** |
4604 | * smack_audit_rule_init - Initialize a smack audit rule |
4605 | * @field: audit rule fields given from user-space (audit.h) |
4606 | * @op: required testing operator (=, !=, >, <, ...) |
4607 | * @rulestr: smack label to be audited |
4608 | * @vrule: pointer to save our own audit rule representation |
4609 | * |
4610 | * Prepare to audit cases where (@field @op @rulestr) is true. |
4611 | * The label to be audited is created if necessay. |
4612 | */ |
4613 | static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) |
4614 | { |
4615 | struct smack_known *skp; |
4616 | char **rule = (char **)vrule; |
4617 | *rule = NULL; |
4618 | |
4619 | if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) |
4620 | return -EINVAL; |
4621 | |
4622 | if (op != Audit_equal && op != Audit_not_equal) |
4623 | return -EINVAL; |
4624 | |
4625 | skp = smk_import_entry(rulestr, 0); |
4626 | if (IS_ERR(ptr: skp)) |
4627 | return PTR_ERR(ptr: skp); |
4628 | |
4629 | *rule = skp->smk_known; |
4630 | |
4631 | return 0; |
4632 | } |
4633 | |
4634 | /** |
4635 | * smack_audit_rule_known - Distinguish Smack audit rules |
4636 | * @krule: rule of interest, in Audit kernel representation format |
4637 | * |
4638 | * This is used to filter Smack rules from remaining Audit ones. |
4639 | * If it's proved that this rule belongs to us, the |
4640 | * audit_rule_match hook will be called to do the final judgement. |
4641 | */ |
4642 | static int smack_audit_rule_known(struct audit_krule *krule) |
4643 | { |
4644 | struct audit_field *f; |
4645 | int i; |
4646 | |
4647 | for (i = 0; i < krule->field_count; i++) { |
4648 | f = &krule->fields[i]; |
4649 | |
4650 | if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER) |
4651 | return 1; |
4652 | } |
4653 | |
4654 | return 0; |
4655 | } |
4656 | |
4657 | /** |
4658 | * smack_audit_rule_match - Audit given object ? |
4659 | * @secid: security id for identifying the object to test |
4660 | * @field: audit rule flags given from user-space |
4661 | * @op: required testing operator |
4662 | * @vrule: smack internal rule presentation |
4663 | * |
4664 | * The core Audit hook. It's used to take the decision of |
4665 | * whether to audit or not to audit a given object. |
4666 | */ |
4667 | static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule) |
4668 | { |
4669 | struct smack_known *skp; |
4670 | char *rule = vrule; |
4671 | |
4672 | if (unlikely(!rule)) { |
4673 | WARN_ONCE(1, "Smack: missing rule\n" ); |
4674 | return -ENOENT; |
4675 | } |
4676 | |
4677 | if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) |
4678 | return 0; |
4679 | |
4680 | skp = smack_from_secid(secid); |
4681 | |
4682 | /* |
4683 | * No need to do string comparisons. If a match occurs, |
4684 | * both pointers will point to the same smack_known |
4685 | * label. |
4686 | */ |
4687 | if (op == Audit_equal) |
4688 | return (rule == skp->smk_known); |
4689 | if (op == Audit_not_equal) |
4690 | return (rule != skp->smk_known); |
4691 | |
4692 | return 0; |
4693 | } |
4694 | |
4695 | /* |
4696 | * There is no need for a smack_audit_rule_free hook. |
4697 | * No memory was allocated. |
4698 | */ |
4699 | |
4700 | #endif /* CONFIG_AUDIT */ |
4701 | |
4702 | /** |
4703 | * smack_ismaclabel - check if xattr @name references a smack MAC label |
4704 | * @name: Full xattr name to check. |
4705 | */ |
4706 | static int smack_ismaclabel(const char *name) |
4707 | { |
4708 | return (strcmp(name, XATTR_SMACK_SUFFIX) == 0); |
4709 | } |
4710 | |
4711 | |
4712 | /** |
4713 | * smack_secid_to_secctx - return the smack label for a secid |
4714 | * @secid: incoming integer |
4715 | * @secdata: destination |
4716 | * @seclen: how long it is |
4717 | * |
4718 | * Exists for networking code. |
4719 | */ |
4720 | static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) |
4721 | { |
4722 | struct smack_known *skp = smack_from_secid(secid); |
4723 | |
4724 | if (secdata) |
4725 | *secdata = skp->smk_known; |
4726 | *seclen = strlen(skp->smk_known); |
4727 | return 0; |
4728 | } |
4729 | |
4730 | /** |
4731 | * smack_secctx_to_secid - return the secid for a smack label |
4732 | * @secdata: smack label |
4733 | * @seclen: how long result is |
4734 | * @secid: outgoing integer |
4735 | * |
4736 | * Exists for audit and networking code. |
4737 | */ |
4738 | static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) |
4739 | { |
4740 | struct smack_known *skp = smk_find_entry(secdata); |
4741 | |
4742 | if (skp) |
4743 | *secid = skp->smk_secid; |
4744 | else |
4745 | *secid = 0; |
4746 | return 0; |
4747 | } |
4748 | |
4749 | /* |
4750 | * There used to be a smack_release_secctx hook |
4751 | * that did nothing back when hooks were in a vector. |
4752 | * Now that there's a list such a hook adds cost. |
4753 | */ |
4754 | |
4755 | static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) |
4756 | { |
4757 | return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, value: ctx, |
4758 | size: ctxlen, flags: 0); |
4759 | } |
4760 | |
4761 | static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) |
4762 | { |
4763 | return __vfs_setxattr_noperm(&nop_mnt_idmap, dentry, XATTR_NAME_SMACK, |
4764 | ctx, ctxlen, 0); |
4765 | } |
4766 | |
4767 | static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) |
4768 | { |
4769 | struct smack_known *skp = smk_of_inode(isp: inode); |
4770 | |
4771 | *ctx = skp->smk_known; |
4772 | *ctxlen = strlen(skp->smk_known); |
4773 | return 0; |
4774 | } |
4775 | |
4776 | static int smack_inode_copy_up(struct dentry *dentry, struct cred **new) |
4777 | { |
4778 | |
4779 | struct task_smack *tsp; |
4780 | struct smack_known *skp; |
4781 | struct inode_smack *isp; |
4782 | struct cred *new_creds = *new; |
4783 | |
4784 | if (new_creds == NULL) { |
4785 | new_creds = prepare_creds(); |
4786 | if (new_creds == NULL) |
4787 | return -ENOMEM; |
4788 | } |
4789 | |
4790 | tsp = smack_cred(cred: new_creds); |
4791 | |
4792 | /* |
4793 | * Get label from overlay inode and set it in create_sid |
4794 | */ |
4795 | isp = smack_inode(inode: d_inode(dentry)); |
4796 | skp = isp->smk_inode; |
4797 | tsp->smk_task = skp; |
4798 | *new = new_creds; |
4799 | return 0; |
4800 | } |
4801 | |
4802 | static int smack_inode_copy_up_xattr(const char *name) |
4803 | { |
4804 | /* |
4805 | * Return 1 if this is the smack access Smack attribute. |
4806 | */ |
4807 | if (strcmp(name, XATTR_NAME_SMACK) == 0) |
4808 | return 1; |
4809 | |
4810 | return -EOPNOTSUPP; |
4811 | } |
4812 | |
4813 | static int smack_dentry_create_files_as(struct dentry *dentry, int mode, |
4814 | struct qstr *name, |
4815 | const struct cred *old, |
4816 | struct cred *new) |
4817 | { |
4818 | struct task_smack *otsp = smack_cred(cred: old); |
4819 | struct task_smack *ntsp = smack_cred(cred: new); |
4820 | struct inode_smack *isp; |
4821 | int may; |
4822 | |
4823 | /* |
4824 | * Use the process credential unless all of |
4825 | * the transmuting criteria are met |
4826 | */ |
4827 | ntsp->smk_task = otsp->smk_task; |
4828 | |
4829 | /* |
4830 | * the attribute of the containing directory |
4831 | */ |
4832 | isp = smack_inode(inode: d_inode(dentry: dentry->d_parent)); |
4833 | |
4834 | if (isp->smk_flags & SMK_INODE_TRANSMUTE) { |
4835 | rcu_read_lock(); |
4836 | may = smk_access_entry(otsp->smk_task->smk_known, |
4837 | isp->smk_inode->smk_known, |
4838 | &otsp->smk_task->smk_rules); |
4839 | rcu_read_unlock(); |
4840 | |
4841 | /* |
4842 | * If the directory is transmuting and the rule |
4843 | * providing access is transmuting use the containing |
4844 | * directory label instead of the process label. |
4845 | */ |
4846 | if (may > 0 && (may & MAY_TRANSMUTE)) { |
4847 | ntsp->smk_task = isp->smk_inode; |
4848 | ntsp->smk_transmuted = ntsp->smk_task; |
4849 | } |
4850 | } |
4851 | return 0; |
4852 | } |
4853 | |
4854 | #ifdef CONFIG_IO_URING |
4855 | /** |
4856 | * smack_uring_override_creds - Is io_uring cred override allowed? |
4857 | * @new: the target creds |
4858 | * |
4859 | * Check to see if the current task is allowed to override it's credentials |
4860 | * to service an io_uring operation. |
4861 | */ |
4862 | static int smack_uring_override_creds(const struct cred *new) |
4863 | { |
4864 | struct task_smack *tsp = smack_cred(current_cred()); |
4865 | struct task_smack *nsp = smack_cred(cred: new); |
4866 | |
4867 | /* |
4868 | * Allow the degenerate case where the new Smack value is |
4869 | * the same as the current Smack value. |
4870 | */ |
4871 | if (tsp->smk_task == nsp->smk_task) |
4872 | return 0; |
4873 | |
4874 | if (smack_privileged_cred(CAP_MAC_OVERRIDE, current_cred())) |
4875 | return 0; |
4876 | |
4877 | return -EPERM; |
4878 | } |
4879 | |
4880 | /** |
4881 | * smack_uring_sqpoll - check if a io_uring polling thread can be created |
4882 | * |
4883 | * Check to see if the current task is allowed to create a new io_uring |
4884 | * kernel polling thread. |
4885 | */ |
4886 | static int smack_uring_sqpoll(void) |
4887 | { |
4888 | if (smack_privileged_cred(CAP_MAC_ADMIN, current_cred())) |
4889 | return 0; |
4890 | |
4891 | return -EPERM; |
4892 | } |
4893 | |
4894 | /** |
4895 | * smack_uring_cmd - check on file operations for io_uring |
4896 | * @ioucmd: the command in question |
4897 | * |
4898 | * Make a best guess about whether a io_uring "command" should |
4899 | * be allowed. Use the same logic used for determining if the |
4900 | * file could be opened for read in the absence of better criteria. |
4901 | */ |
4902 | static int smack_uring_cmd(struct io_uring_cmd *ioucmd) |
4903 | { |
4904 | struct file *file = ioucmd->file; |
4905 | struct smk_audit_info ad; |
4906 | struct task_smack *tsp; |
4907 | struct inode *inode; |
4908 | int rc; |
4909 | |
4910 | if (!file) |
4911 | return -EINVAL; |
4912 | |
4913 | tsp = smack_cred(cred: file->f_cred); |
4914 | inode = file_inode(f: file); |
4915 | |
4916 | smk_ad_init(a: &ad, func: __func__, LSM_AUDIT_DATA_PATH); |
4917 | smk_ad_setfield_u_fs_path(a: &ad, p: file->f_path); |
4918 | rc = smk_tskacc(tsp, smk_of_inode(isp: inode), MAY_READ, &ad); |
4919 | rc = smk_bu_credfile(cred: file->f_cred, file, MAY_READ, rc); |
4920 | |
4921 | return rc; |
4922 | } |
4923 | |
4924 | #endif /* CONFIG_IO_URING */ |
4925 | |
4926 | struct lsm_blob_sizes smack_blob_sizes __ro_after_init = { |
4927 | .lbs_cred = sizeof(struct task_smack), |
4928 | .lbs_file = sizeof(struct smack_known *), |
4929 | .lbs_inode = sizeof(struct inode_smack), |
4930 | .lbs_ipc = sizeof(struct smack_known *), |
4931 | .lbs_msg_msg = sizeof(struct smack_known *), |
4932 | .lbs_superblock = sizeof(struct superblock_smack), |
4933 | .lbs_xattr_count = SMACK_INODE_INIT_XATTRS, |
4934 | }; |
4935 | |
4936 | static struct security_hook_list smack_hooks[] __ro_after_init = { |
4937 | LSM_HOOK_INIT(ptrace_access_check, smack_ptrace_access_check), |
4938 | LSM_HOOK_INIT(ptrace_traceme, smack_ptrace_traceme), |
4939 | LSM_HOOK_INIT(syslog, smack_syslog), |
4940 | |
4941 | LSM_HOOK_INIT(fs_context_submount, smack_fs_context_submount), |
4942 | LSM_HOOK_INIT(fs_context_dup, smack_fs_context_dup), |
4943 | LSM_HOOK_INIT(fs_context_parse_param, smack_fs_context_parse_param), |
4944 | |
4945 | LSM_HOOK_INIT(sb_alloc_security, smack_sb_alloc_security), |
4946 | LSM_HOOK_INIT(sb_free_mnt_opts, smack_free_mnt_opts), |
4947 | LSM_HOOK_INIT(sb_eat_lsm_opts, smack_sb_eat_lsm_opts), |
4948 | LSM_HOOK_INIT(sb_statfs, smack_sb_statfs), |
4949 | LSM_HOOK_INIT(sb_set_mnt_opts, smack_set_mnt_opts), |
4950 | |
4951 | LSM_HOOK_INIT(bprm_creds_for_exec, smack_bprm_creds_for_exec), |
4952 | |
4953 | LSM_HOOK_INIT(inode_alloc_security, smack_inode_alloc_security), |
4954 | LSM_HOOK_INIT(inode_init_security, smack_inode_init_security), |
4955 | LSM_HOOK_INIT(inode_link, smack_inode_link), |
4956 | LSM_HOOK_INIT(inode_unlink, smack_inode_unlink), |
4957 | LSM_HOOK_INIT(inode_rmdir, smack_inode_rmdir), |
4958 | LSM_HOOK_INIT(inode_rename, smack_inode_rename), |
4959 | LSM_HOOK_INIT(inode_permission, smack_inode_permission), |
4960 | LSM_HOOK_INIT(inode_setattr, smack_inode_setattr), |
4961 | LSM_HOOK_INIT(inode_getattr, smack_inode_getattr), |
4962 | LSM_HOOK_INIT(inode_setxattr, smack_inode_setxattr), |
4963 | LSM_HOOK_INIT(inode_post_setxattr, smack_inode_post_setxattr), |
4964 | LSM_HOOK_INIT(inode_getxattr, smack_inode_getxattr), |
4965 | LSM_HOOK_INIT(inode_removexattr, smack_inode_removexattr), |
4966 | LSM_HOOK_INIT(inode_set_acl, smack_inode_set_acl), |
4967 | LSM_HOOK_INIT(inode_get_acl, smack_inode_get_acl), |
4968 | LSM_HOOK_INIT(inode_remove_acl, smack_inode_remove_acl), |
4969 | LSM_HOOK_INIT(inode_getsecurity, smack_inode_getsecurity), |
4970 | LSM_HOOK_INIT(inode_setsecurity, smack_inode_setsecurity), |
4971 | LSM_HOOK_INIT(inode_listsecurity, smack_inode_listsecurity), |
4972 | LSM_HOOK_INIT(inode_getsecid, smack_inode_getsecid), |
4973 | |
4974 | LSM_HOOK_INIT(file_alloc_security, smack_file_alloc_security), |
4975 | LSM_HOOK_INIT(file_ioctl, smack_file_ioctl), |
4976 | LSM_HOOK_INIT(file_lock, smack_file_lock), |
4977 | LSM_HOOK_INIT(file_fcntl, smack_file_fcntl), |
4978 | LSM_HOOK_INIT(mmap_file, smack_mmap_file), |
4979 | LSM_HOOK_INIT(mmap_addr, cap_mmap_addr), |
4980 | LSM_HOOK_INIT(file_set_fowner, smack_file_set_fowner), |
4981 | LSM_HOOK_INIT(file_send_sigiotask, smack_file_send_sigiotask), |
4982 | LSM_HOOK_INIT(file_receive, smack_file_receive), |
4983 | |
4984 | LSM_HOOK_INIT(file_open, smack_file_open), |
4985 | |
4986 | LSM_HOOK_INIT(cred_alloc_blank, smack_cred_alloc_blank), |
4987 | LSM_HOOK_INIT(cred_free, smack_cred_free), |
4988 | LSM_HOOK_INIT(cred_prepare, smack_cred_prepare), |
4989 | LSM_HOOK_INIT(cred_transfer, smack_cred_transfer), |
4990 | LSM_HOOK_INIT(cred_getsecid, smack_cred_getsecid), |
4991 | LSM_HOOK_INIT(kernel_act_as, smack_kernel_act_as), |
4992 | LSM_HOOK_INIT(kernel_create_files_as, smack_kernel_create_files_as), |
4993 | LSM_HOOK_INIT(task_setpgid, smack_task_setpgid), |
4994 | LSM_HOOK_INIT(task_getpgid, smack_task_getpgid), |
4995 | LSM_HOOK_INIT(task_getsid, smack_task_getsid), |
4996 | LSM_HOOK_INIT(current_getsecid_subj, smack_current_getsecid_subj), |
4997 | LSM_HOOK_INIT(task_getsecid_obj, smack_task_getsecid_obj), |
4998 | LSM_HOOK_INIT(task_setnice, smack_task_setnice), |
4999 | LSM_HOOK_INIT(task_setioprio, smack_task_setioprio), |
5000 | LSM_HOOK_INIT(task_getioprio, smack_task_getioprio), |
5001 | LSM_HOOK_INIT(task_setscheduler, smack_task_setscheduler), |
5002 | LSM_HOOK_INIT(task_getscheduler, smack_task_getscheduler), |
5003 | LSM_HOOK_INIT(task_movememory, smack_task_movememory), |
5004 | LSM_HOOK_INIT(task_kill, smack_task_kill), |
5005 | LSM_HOOK_INIT(task_to_inode, smack_task_to_inode), |
5006 | |
5007 | LSM_HOOK_INIT(ipc_permission, smack_ipc_permission), |
5008 | LSM_HOOK_INIT(ipc_getsecid, smack_ipc_getsecid), |
5009 | |
5010 | LSM_HOOK_INIT(msg_msg_alloc_security, smack_msg_msg_alloc_security), |
5011 | |
5012 | LSM_HOOK_INIT(msg_queue_alloc_security, smack_ipc_alloc_security), |
5013 | LSM_HOOK_INIT(msg_queue_associate, smack_msg_queue_associate), |
5014 | LSM_HOOK_INIT(msg_queue_msgctl, smack_msg_queue_msgctl), |
5015 | LSM_HOOK_INIT(msg_queue_msgsnd, smack_msg_queue_msgsnd), |
5016 | LSM_HOOK_INIT(msg_queue_msgrcv, smack_msg_queue_msgrcv), |
5017 | |
5018 | LSM_HOOK_INIT(shm_alloc_security, smack_ipc_alloc_security), |
5019 | LSM_HOOK_INIT(shm_associate, smack_shm_associate), |
5020 | LSM_HOOK_INIT(shm_shmctl, smack_shm_shmctl), |
5021 | LSM_HOOK_INIT(shm_shmat, smack_shm_shmat), |
5022 | |
5023 | LSM_HOOK_INIT(sem_alloc_security, smack_ipc_alloc_security), |
5024 | LSM_HOOK_INIT(sem_associate, smack_sem_associate), |
5025 | LSM_HOOK_INIT(sem_semctl, smack_sem_semctl), |
5026 | LSM_HOOK_INIT(sem_semop, smack_sem_semop), |
5027 | |
5028 | LSM_HOOK_INIT(d_instantiate, smack_d_instantiate), |
5029 | |
5030 | LSM_HOOK_INIT(getprocattr, smack_getprocattr), |
5031 | LSM_HOOK_INIT(setprocattr, smack_setprocattr), |
5032 | |
5033 | LSM_HOOK_INIT(unix_stream_connect, smack_unix_stream_connect), |
5034 | LSM_HOOK_INIT(unix_may_send, smack_unix_may_send), |
5035 | |
5036 | LSM_HOOK_INIT(socket_post_create, smack_socket_post_create), |
5037 | LSM_HOOK_INIT(socket_socketpair, smack_socket_socketpair), |
5038 | #ifdef SMACK_IPV6_PORT_LABELING |
5039 | LSM_HOOK_INIT(socket_bind, smack_socket_bind), |
5040 | #endif |
5041 | LSM_HOOK_INIT(socket_connect, smack_socket_connect), |
5042 | LSM_HOOK_INIT(socket_sendmsg, smack_socket_sendmsg), |
5043 | LSM_HOOK_INIT(socket_sock_rcv_skb, smack_socket_sock_rcv_skb), |
5044 | LSM_HOOK_INIT(socket_getpeersec_stream, smack_socket_getpeersec_stream), |
5045 | LSM_HOOK_INIT(socket_getpeersec_dgram, smack_socket_getpeersec_dgram), |
5046 | LSM_HOOK_INIT(sk_alloc_security, smack_sk_alloc_security), |
5047 | LSM_HOOK_INIT(sk_free_security, smack_sk_free_security), |
5048 | LSM_HOOK_INIT(sk_clone_security, smack_sk_clone_security), |
5049 | LSM_HOOK_INIT(sock_graft, smack_sock_graft), |
5050 | LSM_HOOK_INIT(inet_conn_request, smack_inet_conn_request), |
5051 | LSM_HOOK_INIT(inet_csk_clone, smack_inet_csk_clone), |
5052 | |
5053 | /* key management security hooks */ |
5054 | #ifdef CONFIG_KEYS |
5055 | LSM_HOOK_INIT(key_alloc, smack_key_alloc), |
5056 | LSM_HOOK_INIT(key_free, smack_key_free), |
5057 | LSM_HOOK_INIT(key_permission, smack_key_permission), |
5058 | LSM_HOOK_INIT(key_getsecurity, smack_key_getsecurity), |
5059 | #ifdef CONFIG_KEY_NOTIFICATIONS |
5060 | LSM_HOOK_INIT(watch_key, smack_watch_key), |
5061 | #endif |
5062 | #endif /* CONFIG_KEYS */ |
5063 | |
5064 | #ifdef CONFIG_WATCH_QUEUE |
5065 | LSM_HOOK_INIT(post_notification, smack_post_notification), |
5066 | #endif |
5067 | |
5068 | /* Audit hooks */ |
5069 | #ifdef CONFIG_AUDIT |
5070 | LSM_HOOK_INIT(audit_rule_init, smack_audit_rule_init), |
5071 | LSM_HOOK_INIT(audit_rule_known, smack_audit_rule_known), |
5072 | LSM_HOOK_INIT(audit_rule_match, smack_audit_rule_match), |
5073 | #endif /* CONFIG_AUDIT */ |
5074 | |
5075 | LSM_HOOK_INIT(ismaclabel, smack_ismaclabel), |
5076 | LSM_HOOK_INIT(secid_to_secctx, smack_secid_to_secctx), |
5077 | LSM_HOOK_INIT(secctx_to_secid, smack_secctx_to_secid), |
5078 | LSM_HOOK_INIT(inode_notifysecctx, smack_inode_notifysecctx), |
5079 | LSM_HOOK_INIT(inode_setsecctx, smack_inode_setsecctx), |
5080 | LSM_HOOK_INIT(inode_getsecctx, smack_inode_getsecctx), |
5081 | LSM_HOOK_INIT(inode_copy_up, smack_inode_copy_up), |
5082 | LSM_HOOK_INIT(inode_copy_up_xattr, smack_inode_copy_up_xattr), |
5083 | LSM_HOOK_INIT(dentry_create_files_as, smack_dentry_create_files_as), |
5084 | #ifdef CONFIG_IO_URING |
5085 | LSM_HOOK_INIT(uring_override_creds, smack_uring_override_creds), |
5086 | LSM_HOOK_INIT(uring_sqpoll, smack_uring_sqpoll), |
5087 | LSM_HOOK_INIT(uring_cmd, smack_uring_cmd), |
5088 | #endif |
5089 | }; |
5090 | |
5091 | |
5092 | static __init void init_smack_known_list(void) |
5093 | { |
5094 | /* |
5095 | * Initialize rule list locks |
5096 | */ |
5097 | mutex_init(&smack_known_huh.smk_rules_lock); |
5098 | mutex_init(&smack_known_hat.smk_rules_lock); |
5099 | mutex_init(&smack_known_floor.smk_rules_lock); |
5100 | mutex_init(&smack_known_star.smk_rules_lock); |
5101 | mutex_init(&smack_known_web.smk_rules_lock); |
5102 | /* |
5103 | * Initialize rule lists |
5104 | */ |
5105 | INIT_LIST_HEAD(list: &smack_known_huh.smk_rules); |
5106 | INIT_LIST_HEAD(list: &smack_known_hat.smk_rules); |
5107 | INIT_LIST_HEAD(list: &smack_known_star.smk_rules); |
5108 | INIT_LIST_HEAD(list: &smack_known_floor.smk_rules); |
5109 | INIT_LIST_HEAD(list: &smack_known_web.smk_rules); |
5110 | /* |
5111 | * Create the known labels list |
5112 | */ |
5113 | smk_insert_entry(skp: &smack_known_huh); |
5114 | smk_insert_entry(skp: &smack_known_hat); |
5115 | smk_insert_entry(skp: &smack_known_star); |
5116 | smk_insert_entry(skp: &smack_known_floor); |
5117 | smk_insert_entry(skp: &smack_known_web); |
5118 | } |
5119 | |
5120 | /** |
5121 | * smack_init - initialize the smack system |
5122 | * |
5123 | * Returns 0 on success, -ENOMEM is there's no memory |
5124 | */ |
5125 | static __init int smack_init(void) |
5126 | { |
5127 | struct cred *cred = (struct cred *) current->cred; |
5128 | struct task_smack *tsp; |
5129 | |
5130 | smack_rule_cache = KMEM_CACHE(smack_rule, 0); |
5131 | if (!smack_rule_cache) |
5132 | return -ENOMEM; |
5133 | |
5134 | /* |
5135 | * Set the security state for the initial task. |
5136 | */ |
5137 | tsp = smack_cred(cred); |
5138 | init_task_smack(tsp, task: &smack_known_floor, forked: &smack_known_floor); |
5139 | |
5140 | /* |
5141 | * Register with LSM |
5142 | */ |
5143 | security_add_hooks(hooks: smack_hooks, ARRAY_SIZE(smack_hooks), lsm: "smack" ); |
5144 | smack_enabled = 1; |
5145 | |
5146 | pr_info("Smack: Initializing.\n" ); |
5147 | #ifdef CONFIG_SECURITY_SMACK_NETFILTER |
5148 | pr_info("Smack: Netfilter enabled.\n" ); |
5149 | #endif |
5150 | #ifdef SMACK_IPV6_PORT_LABELING |
5151 | pr_info("Smack: IPv6 port labeling enabled.\n" ); |
5152 | #endif |
5153 | #ifdef SMACK_IPV6_SECMARK_LABELING |
5154 | pr_info("Smack: IPv6 Netfilter enabled.\n" ); |
5155 | #endif |
5156 | |
5157 | /* initialize the smack_known_list */ |
5158 | init_smack_known_list(); |
5159 | |
5160 | return 0; |
5161 | } |
5162 | |
5163 | /* |
5164 | * Smack requires early initialization in order to label |
5165 | * all processes and objects when they are created. |
5166 | */ |
5167 | DEFINE_LSM(smack) = { |
5168 | .name = "smack" , |
5169 | .flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE, |
5170 | .blobs = &smack_blob_sizes, |
5171 | .init = smack_init, |
5172 | }; |
5173 | |