1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* procfs files for key database enumeration |
3 | * |
4 | * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. |
5 | * Written by David Howells (dhowells@redhat.com) |
6 | */ |
7 | |
8 | #include <linux/init.h> |
9 | #include <linux/sched.h> |
10 | #include <linux/fs.h> |
11 | #include <linux/proc_fs.h> |
12 | #include <linux/seq_file.h> |
13 | #include <asm/errno.h> |
14 | #include "internal.h" |
15 | |
16 | static void *proc_keys_start(struct seq_file *p, loff_t *_pos); |
17 | static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos); |
18 | static void proc_keys_stop(struct seq_file *p, void *v); |
19 | static int proc_keys_show(struct seq_file *m, void *v); |
20 | |
21 | static const struct seq_operations proc_keys_ops = { |
22 | .start = proc_keys_start, |
23 | .next = proc_keys_next, |
24 | .stop = proc_keys_stop, |
25 | .show = proc_keys_show, |
26 | }; |
27 | |
28 | static void *proc_key_users_start(struct seq_file *p, loff_t *_pos); |
29 | static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos); |
30 | static void proc_key_users_stop(struct seq_file *p, void *v); |
31 | static int proc_key_users_show(struct seq_file *m, void *v); |
32 | |
33 | static const struct seq_operations proc_key_users_ops = { |
34 | .start = proc_key_users_start, |
35 | .next = proc_key_users_next, |
36 | .stop = proc_key_users_stop, |
37 | .show = proc_key_users_show, |
38 | }; |
39 | |
40 | /* |
41 | * Declare the /proc files. |
42 | */ |
43 | static int __init key_proc_init(void) |
44 | { |
45 | struct proc_dir_entry *p; |
46 | |
47 | p = proc_create_seq("keys" , 0, NULL, &proc_keys_ops); |
48 | if (!p) |
49 | panic(fmt: "Cannot create /proc/keys\n" ); |
50 | |
51 | p = proc_create_seq("key-users" , 0, NULL, &proc_key_users_ops); |
52 | if (!p) |
53 | panic(fmt: "Cannot create /proc/key-users\n" ); |
54 | |
55 | return 0; |
56 | } |
57 | |
58 | __initcall(key_proc_init); |
59 | |
60 | /* |
61 | * Implement "/proc/keys" to provide a list of the keys on the system that |
62 | * grant View permission to the caller. |
63 | */ |
64 | static struct rb_node *key_serial_next(struct seq_file *p, struct rb_node *n) |
65 | { |
66 | struct user_namespace *user_ns = seq_user_ns(seq: p); |
67 | |
68 | n = rb_next(n); |
69 | while (n) { |
70 | struct key *key = rb_entry(n, struct key, serial_node); |
71 | if (kuid_has_mapping(ns: user_ns, uid: key->user->uid)) |
72 | break; |
73 | n = rb_next(n); |
74 | } |
75 | return n; |
76 | } |
77 | |
78 | static struct key *find_ge_key(struct seq_file *p, key_serial_t id) |
79 | { |
80 | struct user_namespace *user_ns = seq_user_ns(seq: p); |
81 | struct rb_node *n = key_serial_tree.rb_node; |
82 | struct key *minkey = NULL; |
83 | |
84 | while (n) { |
85 | struct key *key = rb_entry(n, struct key, serial_node); |
86 | if (id < key->serial) { |
87 | if (!minkey || minkey->serial > key->serial) |
88 | minkey = key; |
89 | n = n->rb_left; |
90 | } else if (id > key->serial) { |
91 | n = n->rb_right; |
92 | } else { |
93 | minkey = key; |
94 | break; |
95 | } |
96 | key = NULL; |
97 | } |
98 | |
99 | if (!minkey) |
100 | return NULL; |
101 | |
102 | for (;;) { |
103 | if (kuid_has_mapping(ns: user_ns, uid: minkey->user->uid)) |
104 | return minkey; |
105 | n = rb_next(&minkey->serial_node); |
106 | if (!n) |
107 | return NULL; |
108 | minkey = rb_entry(n, struct key, serial_node); |
109 | } |
110 | } |
111 | |
112 | static void *proc_keys_start(struct seq_file *p, loff_t *_pos) |
113 | __acquires(key_serial_lock) |
114 | { |
115 | key_serial_t pos = *_pos; |
116 | struct key *key; |
117 | |
118 | spin_lock(lock: &key_serial_lock); |
119 | |
120 | if (*_pos > INT_MAX) |
121 | return NULL; |
122 | key = find_ge_key(p, id: pos); |
123 | if (!key) |
124 | return NULL; |
125 | *_pos = key->serial; |
126 | return &key->serial_node; |
127 | } |
128 | |
129 | static inline key_serial_t key_node_serial(struct rb_node *n) |
130 | { |
131 | struct key *key = rb_entry(n, struct key, serial_node); |
132 | return key->serial; |
133 | } |
134 | |
135 | static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos) |
136 | { |
137 | struct rb_node *n; |
138 | |
139 | n = key_serial_next(p, n: v); |
140 | if (n) |
141 | *_pos = key_node_serial(n); |
142 | else |
143 | (*_pos)++; |
144 | return n; |
145 | } |
146 | |
147 | static void proc_keys_stop(struct seq_file *p, void *v) |
148 | __releases(key_serial_lock) |
149 | { |
150 | spin_unlock(lock: &key_serial_lock); |
151 | } |
152 | |
153 | static int proc_keys_show(struct seq_file *m, void *v) |
154 | { |
155 | struct rb_node *_p = v; |
156 | struct key *key = rb_entry(_p, struct key, serial_node); |
157 | unsigned long flags; |
158 | key_ref_t key_ref, skey_ref; |
159 | time64_t now, expiry; |
160 | char xbuf[16]; |
161 | short state; |
162 | u64 timo; |
163 | int rc; |
164 | |
165 | struct keyring_search_context ctx = { |
166 | .index_key = key->index_key, |
167 | .cred = m->file->f_cred, |
168 | .match_data.cmp = lookup_user_key_possessed, |
169 | .match_data.raw_data = key, |
170 | .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, |
171 | .flags = (KEYRING_SEARCH_NO_STATE_CHECK | |
172 | KEYRING_SEARCH_RECURSE), |
173 | }; |
174 | |
175 | key_ref = make_key_ref(key, possession: 0); |
176 | |
177 | /* determine if the key is possessed by this process (a test we can |
178 | * skip if the key does not indicate the possessor can view it |
179 | */ |
180 | if (key->perm & KEY_POS_VIEW) { |
181 | rcu_read_lock(); |
182 | skey_ref = search_cred_keyrings_rcu(ctx: &ctx); |
183 | rcu_read_unlock(); |
184 | if (!IS_ERR(ptr: skey_ref)) { |
185 | key_ref_put(key_ref: skey_ref); |
186 | key_ref = make_key_ref(key, possession: 1); |
187 | } |
188 | } |
189 | |
190 | /* check whether the current task is allowed to view the key */ |
191 | rc = key_task_permission(key_ref, cred: ctx.cred, need_perm: KEY_NEED_VIEW); |
192 | if (rc < 0) |
193 | return 0; |
194 | |
195 | now = ktime_get_real_seconds(); |
196 | |
197 | rcu_read_lock(); |
198 | |
199 | /* come up with a suitable timeout value */ |
200 | expiry = READ_ONCE(key->expiry); |
201 | if (expiry == 0) { |
202 | memcpy(xbuf, "perm" , 5); |
203 | } else if (now >= expiry) { |
204 | memcpy(xbuf, "expd" , 5); |
205 | } else { |
206 | timo = expiry - now; |
207 | |
208 | if (timo < 60) |
209 | sprintf(buf: xbuf, fmt: "%llus" , timo); |
210 | else if (timo < 60*60) |
211 | sprintf(buf: xbuf, fmt: "%llum" , div_u64(dividend: timo, divisor: 60)); |
212 | else if (timo < 60*60*24) |
213 | sprintf(buf: xbuf, fmt: "%lluh" , div_u64(dividend: timo, divisor: 60 * 60)); |
214 | else if (timo < 60*60*24*7) |
215 | sprintf(buf: xbuf, fmt: "%llud" , div_u64(dividend: timo, divisor: 60 * 60 * 24)); |
216 | else |
217 | sprintf(buf: xbuf, fmt: "%lluw" , div_u64(dividend: timo, divisor: 60 * 60 * 24 * 7)); |
218 | } |
219 | |
220 | state = key_read_state(key); |
221 | |
222 | #define showflag(FLAGS, LETTER, FLAG) \ |
223 | ((FLAGS & (1 << FLAG)) ? LETTER : '-') |
224 | |
225 | flags = READ_ONCE(key->flags); |
226 | seq_printf(m, fmt: "%08x %c%c%c%c%c%c%c %5d %4s %08x %5d %5d %-9.9s " , |
227 | key->serial, |
228 | state != KEY_IS_UNINSTANTIATED ? 'I' : '-', |
229 | showflag(flags, 'R', KEY_FLAG_REVOKED), |
230 | showflag(flags, 'D', KEY_FLAG_DEAD), |
231 | showflag(flags, 'Q', KEY_FLAG_IN_QUOTA), |
232 | showflag(flags, 'U', KEY_FLAG_USER_CONSTRUCT), |
233 | state < 0 ? 'N' : '-', |
234 | showflag(flags, 'i', KEY_FLAG_INVALIDATED), |
235 | refcount_read(r: &key->usage), |
236 | xbuf, |
237 | key->perm, |
238 | from_kuid_munged(to: seq_user_ns(seq: m), uid: key->uid), |
239 | from_kgid_munged(to: seq_user_ns(seq: m), gid: key->gid), |
240 | key->type->name); |
241 | |
242 | #undef showflag |
243 | |
244 | if (key->type->describe) |
245 | key->type->describe(key, m); |
246 | seq_putc(m, c: '\n'); |
247 | |
248 | rcu_read_unlock(); |
249 | return 0; |
250 | } |
251 | |
252 | static struct rb_node *__key_user_next(struct user_namespace *user_ns, struct rb_node *n) |
253 | { |
254 | while (n) { |
255 | struct key_user *user = rb_entry(n, struct key_user, node); |
256 | if (kuid_has_mapping(ns: user_ns, uid: user->uid)) |
257 | break; |
258 | n = rb_next(n); |
259 | } |
260 | return n; |
261 | } |
262 | |
263 | static struct rb_node *key_user_next(struct user_namespace *user_ns, struct rb_node *n) |
264 | { |
265 | return __key_user_next(user_ns, n: rb_next(n)); |
266 | } |
267 | |
268 | static struct rb_node *key_user_first(struct user_namespace *user_ns, struct rb_root *r) |
269 | { |
270 | struct rb_node *n = rb_first(r); |
271 | return __key_user_next(user_ns, n); |
272 | } |
273 | |
274 | static void *proc_key_users_start(struct seq_file *p, loff_t *_pos) |
275 | __acquires(key_user_lock) |
276 | { |
277 | struct rb_node *_p; |
278 | loff_t pos = *_pos; |
279 | |
280 | spin_lock(lock: &key_user_lock); |
281 | |
282 | _p = key_user_first(user_ns: seq_user_ns(seq: p), r: &key_user_tree); |
283 | while (pos > 0 && _p) { |
284 | pos--; |
285 | _p = key_user_next(user_ns: seq_user_ns(seq: p), n: _p); |
286 | } |
287 | |
288 | return _p; |
289 | } |
290 | |
291 | static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos) |
292 | { |
293 | (*_pos)++; |
294 | return key_user_next(user_ns: seq_user_ns(seq: p), n: (struct rb_node *)v); |
295 | } |
296 | |
297 | static void proc_key_users_stop(struct seq_file *p, void *v) |
298 | __releases(key_user_lock) |
299 | { |
300 | spin_unlock(lock: &key_user_lock); |
301 | } |
302 | |
303 | static int proc_key_users_show(struct seq_file *m, void *v) |
304 | { |
305 | struct rb_node *_p = v; |
306 | struct key_user *user = rb_entry(_p, struct key_user, node); |
307 | unsigned maxkeys = uid_eq(left: user->uid, GLOBAL_ROOT_UID) ? |
308 | key_quota_root_maxkeys : key_quota_maxkeys; |
309 | unsigned maxbytes = uid_eq(left: user->uid, GLOBAL_ROOT_UID) ? |
310 | key_quota_root_maxbytes : key_quota_maxbytes; |
311 | |
312 | seq_printf(m, fmt: "%5u: %5d %d/%d %d/%d %d/%d\n" , |
313 | from_kuid_munged(to: seq_user_ns(seq: m), uid: user->uid), |
314 | refcount_read(r: &user->usage), |
315 | atomic_read(v: &user->nkeys), |
316 | atomic_read(v: &user->nikeys), |
317 | user->qnkeys, |
318 | maxkeys, |
319 | user->qnbytes, |
320 | maxbytes); |
321 | |
322 | return 0; |
323 | } |
324 | |