1 | /* |
2 | * linux/fs/exec.c |
3 | * |
4 | * Copyright (C) 1991, 1992 Linus Torvalds |
5 | */ |
6 | |
7 | /* |
8 | * #!-checking implemented by tytso. |
9 | */ |
10 | /* |
11 | * Demand-loading implemented 01.12.91 - no need to read anything but |
12 | * the header into memory. The inode of the executable is put into |
13 | * "current->executable", and page faults do the actual loading. Clean. |
14 | * |
15 | * Once more I can proudly say that linux stood up to being changed: it |
16 | * was less than 2 hours work to get demand-loading completely implemented. |
17 | * |
18 | * Demand loading changed July 1993 by Eric Youngdale. Use mmap instead, |
19 | * current->executable is only used by the procfs. This allows a dispatch |
20 | * table to check for several different types of binary formats. We keep |
21 | * trying until we recognize the file or we run out of supported binary |
22 | * formats. |
23 | */ |
24 | |
25 | #include <linux/slab.h> |
26 | #include <linux/file.h> |
27 | #include <linux/fdtable.h> |
28 | #include <linux/mm.h> |
29 | #include <linux/vmacache.h> |
30 | #include <linux/stat.h> |
31 | #include <linux/fcntl.h> |
32 | #include <linux/swap.h> |
33 | #include <linux/string.h> |
34 | #include <linux/init.h> |
35 | #include <linux/sched/mm.h> |
36 | #include <linux/sched/coredump.h> |
37 | #include <linux/sched/signal.h> |
38 | #include <linux/sched/numa_balancing.h> |
39 | #include <linux/sched/task.h> |
40 | #include <linux/pagemap.h> |
41 | #include <linux/perf_event.h> |
42 | #include <linux/highmem.h> |
43 | #include <linux/spinlock.h> |
44 | #include <linux/key.h> |
45 | #include <linux/personality.h> |
46 | #include <linux/binfmts.h> |
47 | #include <linux/utsname.h> |
48 | #include <linux/pid_namespace.h> |
49 | #include <linux/module.h> |
50 | #include <linux/namei.h> |
51 | #include <linux/mount.h> |
52 | #include <linux/security.h> |
53 | #include <linux/syscalls.h> |
54 | #include <linux/tsacct_kern.h> |
55 | #include <linux/cn_proc.h> |
56 | #include <linux/audit.h> |
57 | #include <linux/tracehook.h> |
58 | #include <linux/kmod.h> |
59 | #include <linux/fsnotify.h> |
60 | #include <linux/fs_struct.h> |
61 | #include <linux/pipe_fs_i.h> |
62 | #include <linux/oom.h> |
63 | #include <linux/compat.h> |
64 | #include <linux/vmalloc.h> |
65 | |
66 | #include <linux/uaccess.h> |
67 | #include <asm/mmu_context.h> |
68 | #include <asm/tlb.h> |
69 | |
70 | #include <trace/events/task.h> |
71 | #include "internal.h" |
72 | |
73 | #include <trace/events/sched.h> |
74 | |
75 | int suid_dumpable = 0; |
76 | |
77 | static LIST_HEAD(formats); |
78 | static DEFINE_RWLOCK(binfmt_lock); |
79 | |
80 | void __register_binfmt(struct linux_binfmt * fmt, int insert) |
81 | { |
82 | BUG_ON(!fmt); |
83 | if (WARN_ON(!fmt->load_binary)) |
84 | return; |
85 | write_lock(&binfmt_lock); |
86 | insert ? list_add(&fmt->lh, &formats) : |
87 | list_add_tail(&fmt->lh, &formats); |
88 | write_unlock(&binfmt_lock); |
89 | } |
90 | |
91 | EXPORT_SYMBOL(__register_binfmt); |
92 | |
93 | void unregister_binfmt(struct linux_binfmt * fmt) |
94 | { |
95 | write_lock(&binfmt_lock); |
96 | list_del(&fmt->lh); |
97 | write_unlock(&binfmt_lock); |
98 | } |
99 | |
100 | EXPORT_SYMBOL(unregister_binfmt); |
101 | |
102 | static inline void put_binfmt(struct linux_binfmt * fmt) |
103 | { |
104 | module_put(fmt->module); |
105 | } |
106 | |
107 | bool path_noexec(const struct path *path) |
108 | { |
109 | return (path->mnt->mnt_flags & MNT_NOEXEC) || |
110 | (path->mnt->mnt_sb->s_iflags & SB_I_NOEXEC); |
111 | } |
112 | |
113 | #ifdef CONFIG_USELIB |
114 | /* |
115 | * Note that a shared library must be both readable and executable due to |
116 | * security reasons. |
117 | * |
118 | * Also note that we take the address to load from from the file itself. |
119 | */ |
120 | SYSCALL_DEFINE1(uselib, const char __user *, library) |
121 | { |
122 | struct linux_binfmt *fmt; |
123 | struct file *file; |
124 | struct filename *tmp = getname(library); |
125 | int error = PTR_ERR(tmp); |
126 | static const struct open_flags uselib_flags = { |
127 | .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC, |
128 | .acc_mode = MAY_READ | MAY_EXEC, |
129 | .intent = LOOKUP_OPEN, |
130 | .lookup_flags = LOOKUP_FOLLOW, |
131 | }; |
132 | |
133 | if (IS_ERR(tmp)) |
134 | goto out; |
135 | |
136 | file = do_filp_open(AT_FDCWD, tmp, &uselib_flags); |
137 | putname(tmp); |
138 | error = PTR_ERR(file); |
139 | if (IS_ERR(file)) |
140 | goto out; |
141 | |
142 | error = -EINVAL; |
143 | if (!S_ISREG(file_inode(file)->i_mode)) |
144 | goto exit; |
145 | |
146 | error = -EACCES; |
147 | if (path_noexec(&file->f_path)) |
148 | goto exit; |
149 | |
150 | fsnotify_open(file); |
151 | |
152 | error = -ENOEXEC; |
153 | |
154 | read_lock(&binfmt_lock); |
155 | list_for_each_entry(fmt, &formats, lh) { |
156 | if (!fmt->load_shlib) |
157 | continue; |
158 | if (!try_module_get(fmt->module)) |
159 | continue; |
160 | read_unlock(&binfmt_lock); |
161 | error = fmt->load_shlib(file); |
162 | read_lock(&binfmt_lock); |
163 | put_binfmt(fmt); |
164 | if (error != -ENOEXEC) |
165 | break; |
166 | } |
167 | read_unlock(&binfmt_lock); |
168 | exit: |
169 | fput(file); |
170 | out: |
171 | return error; |
172 | } |
173 | #endif /* #ifdef CONFIG_USELIB */ |
174 | |
175 | #ifdef CONFIG_MMU |
176 | /* |
177 | * The nascent bprm->mm is not visible until exec_mmap() but it can |
178 | * use a lot of memory, account these pages in current->mm temporary |
179 | * for oom_badness()->get_mm_rss(). Once exec succeeds or fails, we |
180 | * change the counter back via acct_arg_size(0). |
181 | */ |
182 | static void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) |
183 | { |
184 | struct mm_struct *mm = current->mm; |
185 | long diff = (long)(pages - bprm->vma_pages); |
186 | |
187 | if (!mm || !diff) |
188 | return; |
189 | |
190 | bprm->vma_pages = pages; |
191 | add_mm_counter(mm, MM_ANONPAGES, diff); |
192 | } |
193 | |
194 | static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, |
195 | int write) |
196 | { |
197 | struct page *page; |
198 | int ret; |
199 | unsigned int gup_flags = FOLL_FORCE; |
200 | |
201 | #ifdef CONFIG_STACK_GROWSUP |
202 | if (write) { |
203 | ret = expand_downwards(bprm->vma, pos); |
204 | if (ret < 0) |
205 | return NULL; |
206 | } |
207 | #endif |
208 | |
209 | if (write) |
210 | gup_flags |= FOLL_WRITE; |
211 | |
212 | /* |
213 | * We are doing an exec(). 'current' is the process |
214 | * doing the exec and bprm->mm is the new process's mm. |
215 | */ |
216 | ret = get_user_pages_remote(current, bprm->mm, pos, 1, gup_flags, |
217 | &page, NULL, NULL); |
218 | if (ret <= 0) |
219 | return NULL; |
220 | |
221 | if (write) |
222 | acct_arg_size(bprm, vma_pages(bprm->vma)); |
223 | |
224 | return page; |
225 | } |
226 | |
227 | static void put_arg_page(struct page *page) |
228 | { |
229 | put_page(page); |
230 | } |
231 | |
232 | static void free_arg_pages(struct linux_binprm *bprm) |
233 | { |
234 | } |
235 | |
236 | static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, |
237 | struct page *page) |
238 | { |
239 | flush_cache_page(bprm->vma, pos, page_to_pfn(page)); |
240 | } |
241 | |
242 | static int __bprm_mm_init(struct linux_binprm *bprm) |
243 | { |
244 | int err; |
245 | struct vm_area_struct *vma = NULL; |
246 | struct mm_struct *mm = bprm->mm; |
247 | |
248 | bprm->vma = vma = vm_area_alloc(mm); |
249 | if (!vma) |
250 | return -ENOMEM; |
251 | vma_set_anonymous(vma); |
252 | |
253 | if (down_write_killable(&mm->mmap_sem)) { |
254 | err = -EINTR; |
255 | goto err_free; |
256 | } |
257 | |
258 | /* |
259 | * Place the stack at the largest stack address the architecture |
260 | * supports. Later, we'll move this to an appropriate place. We don't |
261 | * use STACK_TOP because that can depend on attributes which aren't |
262 | * configured yet. |
263 | */ |
264 | BUILD_BUG_ON(VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUP); |
265 | vma->vm_end = STACK_TOP_MAX; |
266 | vma->vm_start = vma->vm_end - PAGE_SIZE; |
267 | vma->vm_flags = VM_SOFTDIRTY | VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP; |
268 | vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); |
269 | |
270 | err = insert_vm_struct(mm, vma); |
271 | if (err) |
272 | goto err; |
273 | |
274 | mm->stack_vm = mm->total_vm = 1; |
275 | arch_bprm_mm_init(mm, vma); |
276 | up_write(&mm->mmap_sem); |
277 | bprm->p = vma->vm_end - sizeof(void *); |
278 | return 0; |
279 | err: |
280 | up_write(&mm->mmap_sem); |
281 | err_free: |
282 | bprm->vma = NULL; |
283 | vm_area_free(vma); |
284 | return err; |
285 | } |
286 | |
287 | static bool valid_arg_len(struct linux_binprm *bprm, long len) |
288 | { |
289 | return len <= MAX_ARG_STRLEN; |
290 | } |
291 | |
292 | #else |
293 | |
294 | static inline void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) |
295 | { |
296 | } |
297 | |
298 | static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, |
299 | int write) |
300 | { |
301 | struct page *page; |
302 | |
303 | page = bprm->page[pos / PAGE_SIZE]; |
304 | if (!page && write) { |
305 | page = alloc_page(GFP_HIGHUSER|__GFP_ZERO); |
306 | if (!page) |
307 | return NULL; |
308 | bprm->page[pos / PAGE_SIZE] = page; |
309 | } |
310 | |
311 | return page; |
312 | } |
313 | |
314 | static void put_arg_page(struct page *page) |
315 | { |
316 | } |
317 | |
318 | static void free_arg_page(struct linux_binprm *bprm, int i) |
319 | { |
320 | if (bprm->page[i]) { |
321 | __free_page(bprm->page[i]); |
322 | bprm->page[i] = NULL; |
323 | } |
324 | } |
325 | |
326 | static void free_arg_pages(struct linux_binprm *bprm) |
327 | { |
328 | int i; |
329 | |
330 | for (i = 0; i < MAX_ARG_PAGES; i++) |
331 | free_arg_page(bprm, i); |
332 | } |
333 | |
334 | static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, |
335 | struct page *page) |
336 | { |
337 | } |
338 | |
339 | static int __bprm_mm_init(struct linux_binprm *bprm) |
340 | { |
341 | bprm->p = PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *); |
342 | return 0; |
343 | } |
344 | |
345 | static bool valid_arg_len(struct linux_binprm *bprm, long len) |
346 | { |
347 | return len <= bprm->p; |
348 | } |
349 | |
350 | #endif /* CONFIG_MMU */ |
351 | |
352 | /* |
353 | * Create a new mm_struct and populate it with a temporary stack |
354 | * vm_area_struct. We don't have enough context at this point to set the stack |
355 | * flags, permissions, and offset, so we use temporary values. We'll update |
356 | * them later in setup_arg_pages(). |
357 | */ |
358 | static int bprm_mm_init(struct linux_binprm *bprm) |
359 | { |
360 | int err; |
361 | struct mm_struct *mm = NULL; |
362 | |
363 | bprm->mm = mm = mm_alloc(); |
364 | err = -ENOMEM; |
365 | if (!mm) |
366 | goto err; |
367 | |
368 | /* Save current stack limit for all calculations made during exec. */ |
369 | task_lock(current->group_leader); |
370 | bprm->rlim_stack = current->signal->rlim[RLIMIT_STACK]; |
371 | task_unlock(current->group_leader); |
372 | |
373 | err = __bprm_mm_init(bprm); |
374 | if (err) |
375 | goto err; |
376 | |
377 | return 0; |
378 | |
379 | err: |
380 | if (mm) { |
381 | bprm->mm = NULL; |
382 | mmdrop(mm); |
383 | } |
384 | |
385 | return err; |
386 | } |
387 | |
388 | struct user_arg_ptr { |
389 | #ifdef CONFIG_COMPAT |
390 | bool is_compat; |
391 | #endif |
392 | union { |
393 | const char __user *const __user *native; |
394 | #ifdef CONFIG_COMPAT |
395 | const compat_uptr_t __user *compat; |
396 | #endif |
397 | } ptr; |
398 | }; |
399 | |
400 | static const char __user *get_user_arg_ptr(struct user_arg_ptr argv, int nr) |
401 | { |
402 | const char __user *native; |
403 | |
404 | #ifdef CONFIG_COMPAT |
405 | if (unlikely(argv.is_compat)) { |
406 | compat_uptr_t compat; |
407 | |
408 | if (get_user(compat, argv.ptr.compat + nr)) |
409 | return ERR_PTR(-EFAULT); |
410 | |
411 | return compat_ptr(compat); |
412 | } |
413 | #endif |
414 | |
415 | if (get_user(native, argv.ptr.native + nr)) |
416 | return ERR_PTR(-EFAULT); |
417 | |
418 | return native; |
419 | } |
420 | |
421 | /* |
422 | * count() counts the number of strings in array ARGV. |
423 | */ |
424 | static int count(struct user_arg_ptr argv, int max) |
425 | { |
426 | int i = 0; |
427 | |
428 | if (argv.ptr.native != NULL) { |
429 | for (;;) { |
430 | const char __user *p = get_user_arg_ptr(argv, i); |
431 | |
432 | if (!p) |
433 | break; |
434 | |
435 | if (IS_ERR(p)) |
436 | return -EFAULT; |
437 | |
438 | if (i >= max) |
439 | return -E2BIG; |
440 | ++i; |
441 | |
442 | if (fatal_signal_pending(current)) |
443 | return -ERESTARTNOHAND; |
444 | cond_resched(); |
445 | } |
446 | } |
447 | return i; |
448 | } |
449 | |
450 | static int prepare_arg_pages(struct linux_binprm *bprm, |
451 | struct user_arg_ptr argv, struct user_arg_ptr envp) |
452 | { |
453 | unsigned long limit, ptr_size; |
454 | |
455 | bprm->argc = count(argv, MAX_ARG_STRINGS); |
456 | if (bprm->argc < 0) |
457 | return bprm->argc; |
458 | |
459 | bprm->envc = count(envp, MAX_ARG_STRINGS); |
460 | if (bprm->envc < 0) |
461 | return bprm->envc; |
462 | |
463 | /* |
464 | * Limit to 1/4 of the max stack size or 3/4 of _STK_LIM |
465 | * (whichever is smaller) for the argv+env strings. |
466 | * This ensures that: |
467 | * - the remaining binfmt code will not run out of stack space, |
468 | * - the program will have a reasonable amount of stack left |
469 | * to work from. |
470 | */ |
471 | limit = _STK_LIM / 4 * 3; |
472 | limit = min(limit, bprm->rlim_stack.rlim_cur / 4); |
473 | /* |
474 | * We've historically supported up to 32 pages (ARG_MAX) |
475 | * of argument strings even with small stacks |
476 | */ |
477 | limit = max_t(unsigned long, limit, ARG_MAX); |
478 | /* |
479 | * We must account for the size of all the argv and envp pointers to |
480 | * the argv and envp strings, since they will also take up space in |
481 | * the stack. They aren't stored until much later when we can't |
482 | * signal to the parent that the child has run out of stack space. |
483 | * Instead, calculate it here so it's possible to fail gracefully. |
484 | */ |
485 | ptr_size = (bprm->argc + bprm->envc) * sizeof(void *); |
486 | if (limit <= ptr_size) |
487 | return -E2BIG; |
488 | limit -= ptr_size; |
489 | |
490 | bprm->argmin = bprm->p - limit; |
491 | return 0; |
492 | } |
493 | |
494 | /* |
495 | * 'copy_strings()' copies argument/environment strings from the old |
496 | * processes's memory to the new process's stack. The call to get_user_pages() |
497 | * ensures the destination page is created and not swapped out. |
498 | */ |
499 | static int copy_strings(int argc, struct user_arg_ptr argv, |
500 | struct linux_binprm *bprm) |
501 | { |
502 | struct page *kmapped_page = NULL; |
503 | char *kaddr = NULL; |
504 | unsigned long kpos = 0; |
505 | int ret; |
506 | |
507 | while (argc-- > 0) { |
508 | const char __user *str; |
509 | int len; |
510 | unsigned long pos; |
511 | |
512 | ret = -EFAULT; |
513 | str = get_user_arg_ptr(argv, argc); |
514 | if (IS_ERR(str)) |
515 | goto out; |
516 | |
517 | len = strnlen_user(str, MAX_ARG_STRLEN); |
518 | if (!len) |
519 | goto out; |
520 | |
521 | ret = -E2BIG; |
522 | if (!valid_arg_len(bprm, len)) |
523 | goto out; |
524 | |
525 | /* We're going to work our way backwords. */ |
526 | pos = bprm->p; |
527 | str += len; |
528 | bprm->p -= len; |
529 | #ifdef CONFIG_MMU |
530 | if (bprm->p < bprm->argmin) |
531 | goto out; |
532 | #endif |
533 | |
534 | while (len > 0) { |
535 | int offset, bytes_to_copy; |
536 | |
537 | if (fatal_signal_pending(current)) { |
538 | ret = -ERESTARTNOHAND; |
539 | goto out; |
540 | } |
541 | cond_resched(); |
542 | |
543 | offset = pos % PAGE_SIZE; |
544 | if (offset == 0) |
545 | offset = PAGE_SIZE; |
546 | |
547 | bytes_to_copy = offset; |
548 | if (bytes_to_copy > len) |
549 | bytes_to_copy = len; |
550 | |
551 | offset -= bytes_to_copy; |
552 | pos -= bytes_to_copy; |
553 | str -= bytes_to_copy; |
554 | len -= bytes_to_copy; |
555 | |
556 | if (!kmapped_page || kpos != (pos & PAGE_MASK)) { |
557 | struct page *page; |
558 | |
559 | page = get_arg_page(bprm, pos, 1); |
560 | if (!page) { |
561 | ret = -E2BIG; |
562 | goto out; |
563 | } |
564 | |
565 | if (kmapped_page) { |
566 | flush_kernel_dcache_page(kmapped_page); |
567 | kunmap(kmapped_page); |
568 | put_arg_page(kmapped_page); |
569 | } |
570 | kmapped_page = page; |
571 | kaddr = kmap(kmapped_page); |
572 | kpos = pos & PAGE_MASK; |
573 | flush_arg_page(bprm, kpos, kmapped_page); |
574 | } |
575 | if (copy_from_user(kaddr+offset, str, bytes_to_copy)) { |
576 | ret = -EFAULT; |
577 | goto out; |
578 | } |
579 | } |
580 | } |
581 | ret = 0; |
582 | out: |
583 | if (kmapped_page) { |
584 | flush_kernel_dcache_page(kmapped_page); |
585 | kunmap(kmapped_page); |
586 | put_arg_page(kmapped_page); |
587 | } |
588 | return ret; |
589 | } |
590 | |
591 | /* |
592 | * Like copy_strings, but get argv and its values from kernel memory. |
593 | */ |
594 | int copy_strings_kernel(int argc, const char *const *__argv, |
595 | struct linux_binprm *bprm) |
596 | { |
597 | int r; |
598 | mm_segment_t oldfs = get_fs(); |
599 | struct user_arg_ptr argv = { |
600 | .ptr.native = (const char __user *const __user *)__argv, |
601 | }; |
602 | |
603 | set_fs(KERNEL_DS); |
604 | r = copy_strings(argc, argv, bprm); |
605 | set_fs(oldfs); |
606 | |
607 | return r; |
608 | } |
609 | EXPORT_SYMBOL(copy_strings_kernel); |
610 | |
611 | #ifdef CONFIG_MMU |
612 | |
613 | /* |
614 | * During bprm_mm_init(), we create a temporary stack at STACK_TOP_MAX. Once |
615 | * the binfmt code determines where the new stack should reside, we shift it to |
616 | * its final location. The process proceeds as follows: |
617 | * |
618 | * 1) Use shift to calculate the new vma endpoints. |
619 | * 2) Extend vma to cover both the old and new ranges. This ensures the |
620 | * arguments passed to subsequent functions are consistent. |
621 | * 3) Move vma's page tables to the new range. |
622 | * 4) Free up any cleared pgd range. |
623 | * 5) Shrink the vma to cover only the new range. |
624 | */ |
625 | static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) |
626 | { |
627 | struct mm_struct *mm = vma->vm_mm; |
628 | unsigned long old_start = vma->vm_start; |
629 | unsigned long old_end = vma->vm_end; |
630 | unsigned long length = old_end - old_start; |
631 | unsigned long new_start = old_start - shift; |
632 | unsigned long new_end = old_end - shift; |
633 | struct mmu_gather tlb; |
634 | |
635 | BUG_ON(new_start > new_end); |
636 | |
637 | /* |
638 | * ensure there are no vmas between where we want to go |
639 | * and where we are |
640 | */ |
641 | if (vma != find_vma(mm, new_start)) |
642 | return -EFAULT; |
643 | |
644 | /* |
645 | * cover the whole range: [new_start, old_end) |
646 | */ |
647 | if (vma_adjust(vma, new_start, old_end, vma->vm_pgoff, NULL)) |
648 | return -ENOMEM; |
649 | |
650 | /* |
651 | * move the page tables downwards, on failure we rely on |
652 | * process cleanup to remove whatever mess we made. |
653 | */ |
654 | if (length != move_page_tables(vma, old_start, |
655 | vma, new_start, length, false)) |
656 | return -ENOMEM; |
657 | |
658 | lru_add_drain(); |
659 | tlb_gather_mmu(&tlb, mm, old_start, old_end); |
660 | if (new_end > old_start) { |
661 | /* |
662 | * when the old and new regions overlap clear from new_end. |
663 | */ |
664 | free_pgd_range(&tlb, new_end, old_end, new_end, |
665 | vma->vm_next ? vma->vm_next->vm_start : USER_PGTABLES_CEILING); |
666 | } else { |
667 | /* |
668 | * otherwise, clean from old_start; this is done to not touch |
669 | * the address space in [new_end, old_start) some architectures |
670 | * have constraints on va-space that make this illegal (IA64) - |
671 | * for the others its just a little faster. |
672 | */ |
673 | free_pgd_range(&tlb, old_start, old_end, new_end, |
674 | vma->vm_next ? vma->vm_next->vm_start : USER_PGTABLES_CEILING); |
675 | } |
676 | tlb_finish_mmu(&tlb, old_start, old_end); |
677 | |
678 | /* |
679 | * Shrink the vma to just the new range. Always succeeds. |
680 | */ |
681 | vma_adjust(vma, new_start, new_end, vma->vm_pgoff, NULL); |
682 | |
683 | return 0; |
684 | } |
685 | |
686 | /* |
687 | * Finalizes the stack vm_area_struct. The flags and permissions are updated, |
688 | * the stack is optionally relocated, and some extra space is added. |
689 | */ |
690 | int setup_arg_pages(struct linux_binprm *bprm, |
691 | unsigned long stack_top, |
692 | int executable_stack) |
693 | { |
694 | unsigned long ret; |
695 | unsigned long stack_shift; |
696 | struct mm_struct *mm = current->mm; |
697 | struct vm_area_struct *vma = bprm->vma; |
698 | struct vm_area_struct *prev = NULL; |
699 | unsigned long vm_flags; |
700 | unsigned long stack_base; |
701 | unsigned long stack_size; |
702 | unsigned long stack_expand; |
703 | unsigned long rlim_stack; |
704 | |
705 | #ifdef CONFIG_STACK_GROWSUP |
706 | /* Limit stack size */ |
707 | stack_base = bprm->rlim_stack.rlim_max; |
708 | if (stack_base > STACK_SIZE_MAX) |
709 | stack_base = STACK_SIZE_MAX; |
710 | |
711 | /* Add space for stack randomization. */ |
712 | stack_base += (STACK_RND_MASK << PAGE_SHIFT); |
713 | |
714 | /* Make sure we didn't let the argument array grow too large. */ |
715 | if (vma->vm_end - vma->vm_start > stack_base) |
716 | return -ENOMEM; |
717 | |
718 | stack_base = PAGE_ALIGN(stack_top - stack_base); |
719 | |
720 | stack_shift = vma->vm_start - stack_base; |
721 | mm->arg_start = bprm->p - stack_shift; |
722 | bprm->p = vma->vm_end - stack_shift; |
723 | #else |
724 | stack_top = arch_align_stack(stack_top); |
725 | stack_top = PAGE_ALIGN(stack_top); |
726 | |
727 | if (unlikely(stack_top < mmap_min_addr) || |
728 | unlikely(vma->vm_end - vma->vm_start >= stack_top - mmap_min_addr)) |
729 | return -ENOMEM; |
730 | |
731 | stack_shift = vma->vm_end - stack_top; |
732 | |
733 | bprm->p -= stack_shift; |
734 | mm->arg_start = bprm->p; |
735 | #endif |
736 | |
737 | if (bprm->loader) |
738 | bprm->loader -= stack_shift; |
739 | bprm->exec -= stack_shift; |
740 | |
741 | if (down_write_killable(&mm->mmap_sem)) |
742 | return -EINTR; |
743 | |
744 | vm_flags = VM_STACK_FLAGS; |
745 | |
746 | /* |
747 | * Adjust stack execute permissions; explicitly enable for |
748 | * EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X and leave alone |
749 | * (arch default) otherwise. |
750 | */ |
751 | if (unlikely(executable_stack == EXSTACK_ENABLE_X)) |
752 | vm_flags |= VM_EXEC; |
753 | else if (executable_stack == EXSTACK_DISABLE_X) |
754 | vm_flags &= ~VM_EXEC; |
755 | vm_flags |= mm->def_flags; |
756 | vm_flags |= VM_STACK_INCOMPLETE_SETUP; |
757 | |
758 | ret = mprotect_fixup(vma, &prev, vma->vm_start, vma->vm_end, |
759 | vm_flags); |
760 | if (ret) |
761 | goto out_unlock; |
762 | BUG_ON(prev != vma); |
763 | |
764 | /* Move stack pages down in memory. */ |
765 | if (stack_shift) { |
766 | ret = shift_arg_pages(vma, stack_shift); |
767 | if (ret) |
768 | goto out_unlock; |
769 | } |
770 | |
771 | /* mprotect_fixup is overkill to remove the temporary stack flags */ |
772 | vma->vm_flags &= ~VM_STACK_INCOMPLETE_SETUP; |
773 | |
774 | stack_expand = 131072UL; /* randomly 32*4k (or 2*64k) pages */ |
775 | stack_size = vma->vm_end - vma->vm_start; |
776 | /* |
777 | * Align this down to a page boundary as expand_stack |
778 | * will align it up. |
779 | */ |
780 | rlim_stack = bprm->rlim_stack.rlim_cur & PAGE_MASK; |
781 | #ifdef CONFIG_STACK_GROWSUP |
782 | if (stack_size + stack_expand > rlim_stack) |
783 | stack_base = vma->vm_start + rlim_stack; |
784 | else |
785 | stack_base = vma->vm_end + stack_expand; |
786 | #else |
787 | if (stack_size + stack_expand > rlim_stack) |
788 | stack_base = vma->vm_end - rlim_stack; |
789 | else |
790 | stack_base = vma->vm_start - stack_expand; |
791 | #endif |
792 | current->mm->start_stack = bprm->p; |
793 | ret = expand_stack(vma, stack_base); |
794 | if (ret) |
795 | ret = -EFAULT; |
796 | |
797 | out_unlock: |
798 | up_write(&mm->mmap_sem); |
799 | return ret; |
800 | } |
801 | EXPORT_SYMBOL(setup_arg_pages); |
802 | |
803 | #else |
804 | |
805 | /* |
806 | * Transfer the program arguments and environment from the holding pages |
807 | * onto the stack. The provided stack pointer is adjusted accordingly. |
808 | */ |
809 | int transfer_args_to_stack(struct linux_binprm *bprm, |
810 | unsigned long *sp_location) |
811 | { |
812 | unsigned long index, stop, sp; |
813 | int ret = 0; |
814 | |
815 | stop = bprm->p >> PAGE_SHIFT; |
816 | sp = *sp_location; |
817 | |
818 | for (index = MAX_ARG_PAGES - 1; index >= stop; index--) { |
819 | unsigned int offset = index == stop ? bprm->p & ~PAGE_MASK : 0; |
820 | char *src = kmap(bprm->page[index]) + offset; |
821 | sp -= PAGE_SIZE - offset; |
822 | if (copy_to_user((void *) sp, src, PAGE_SIZE - offset) != 0) |
823 | ret = -EFAULT; |
824 | kunmap(bprm->page[index]); |
825 | if (ret) |
826 | goto out; |
827 | } |
828 | |
829 | *sp_location = sp; |
830 | |
831 | out: |
832 | return ret; |
833 | } |
834 | EXPORT_SYMBOL(transfer_args_to_stack); |
835 | |
836 | #endif /* CONFIG_MMU */ |
837 | |
838 | static struct file *do_open_execat(int fd, struct filename *name, int flags) |
839 | { |
840 | struct file *file; |
841 | int err; |
842 | struct open_flags open_exec_flags = { |
843 | .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC, |
844 | .acc_mode = MAY_EXEC, |
845 | .intent = LOOKUP_OPEN, |
846 | .lookup_flags = LOOKUP_FOLLOW, |
847 | }; |
848 | |
849 | if ((flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0) |
850 | return ERR_PTR(-EINVAL); |
851 | if (flags & AT_SYMLINK_NOFOLLOW) |
852 | open_exec_flags.lookup_flags &= ~LOOKUP_FOLLOW; |
853 | if (flags & AT_EMPTY_PATH) |
854 | open_exec_flags.lookup_flags |= LOOKUP_EMPTY; |
855 | |
856 | file = do_filp_open(fd, name, &open_exec_flags); |
857 | if (IS_ERR(file)) |
858 | goto out; |
859 | |
860 | err = -EACCES; |
861 | if (!S_ISREG(file_inode(file)->i_mode)) |
862 | goto exit; |
863 | |
864 | if (path_noexec(&file->f_path)) |
865 | goto exit; |
866 | |
867 | err = deny_write_access(file); |
868 | if (err) |
869 | goto exit; |
870 | |
871 | if (name->name[0] != '\0') |
872 | fsnotify_open(file); |
873 | |
874 | out: |
875 | return file; |
876 | |
877 | exit: |
878 | fput(file); |
879 | return ERR_PTR(err); |
880 | } |
881 | |
882 | struct file *open_exec(const char *name) |
883 | { |
884 | struct filename *filename = getname_kernel(name); |
885 | struct file *f = ERR_CAST(filename); |
886 | |
887 | if (!IS_ERR(filename)) { |
888 | f = do_open_execat(AT_FDCWD, filename, 0); |
889 | putname(filename); |
890 | } |
891 | return f; |
892 | } |
893 | EXPORT_SYMBOL(open_exec); |
894 | |
895 | int kernel_read_file(struct file *file, void **buf, loff_t *size, |
896 | loff_t max_size, enum kernel_read_file_id id) |
897 | { |
898 | loff_t i_size, pos; |
899 | ssize_t bytes = 0; |
900 | int ret; |
901 | |
902 | if (!S_ISREG(file_inode(file)->i_mode) || max_size < 0) |
903 | return -EINVAL; |
904 | |
905 | ret = deny_write_access(file); |
906 | if (ret) |
907 | return ret; |
908 | |
909 | ret = security_kernel_read_file(file, id); |
910 | if (ret) |
911 | goto out; |
912 | |
913 | i_size = i_size_read(file_inode(file)); |
914 | if (i_size <= 0) { |
915 | ret = -EINVAL; |
916 | goto out; |
917 | } |
918 | if (i_size > SIZE_MAX || (max_size > 0 && i_size > max_size)) { |
919 | ret = -EFBIG; |
920 | goto out; |
921 | } |
922 | |
923 | if (id != READING_FIRMWARE_PREALLOC_BUFFER) |
924 | *buf = vmalloc(i_size); |
925 | if (!*buf) { |
926 | ret = -ENOMEM; |
927 | goto out; |
928 | } |
929 | |
930 | pos = 0; |
931 | while (pos < i_size) { |
932 | bytes = kernel_read(file, *buf + pos, i_size - pos, &pos); |
933 | if (bytes < 0) { |
934 | ret = bytes; |
935 | goto out_free; |
936 | } |
937 | |
938 | if (bytes == 0) |
939 | break; |
940 | } |
941 | |
942 | if (pos != i_size) { |
943 | ret = -EIO; |
944 | goto out_free; |
945 | } |
946 | |
947 | ret = security_kernel_post_read_file(file, *buf, i_size, id); |
948 | if (!ret) |
949 | *size = pos; |
950 | |
951 | out_free: |
952 | if (ret < 0) { |
953 | if (id != READING_FIRMWARE_PREALLOC_BUFFER) { |
954 | vfree(*buf); |
955 | *buf = NULL; |
956 | } |
957 | } |
958 | |
959 | out: |
960 | allow_write_access(file); |
961 | return ret; |
962 | } |
963 | EXPORT_SYMBOL_GPL(kernel_read_file); |
964 | |
965 | int kernel_read_file_from_path(const char *path, void **buf, loff_t *size, |
966 | loff_t max_size, enum kernel_read_file_id id) |
967 | { |
968 | struct file *file; |
969 | int ret; |
970 | |
971 | if (!path || !*path) |
972 | return -EINVAL; |
973 | |
974 | file = filp_open(path, O_RDONLY, 0); |
975 | if (IS_ERR(file)) |
976 | return PTR_ERR(file); |
977 | |
978 | ret = kernel_read_file(file, buf, size, max_size, id); |
979 | fput(file); |
980 | return ret; |
981 | } |
982 | EXPORT_SYMBOL_GPL(kernel_read_file_from_path); |
983 | |
984 | int kernel_read_file_from_fd(int fd, void **buf, loff_t *size, loff_t max_size, |
985 | enum kernel_read_file_id id) |
986 | { |
987 | struct fd f = fdget(fd); |
988 | int ret = -EBADF; |
989 | |
990 | if (!f.file) |
991 | goto out; |
992 | |
993 | ret = kernel_read_file(f.file, buf, size, max_size, id); |
994 | out: |
995 | fdput(f); |
996 | return ret; |
997 | } |
998 | EXPORT_SYMBOL_GPL(kernel_read_file_from_fd); |
999 | |
1000 | ssize_t read_code(struct file *file, unsigned long addr, loff_t pos, size_t len) |
1001 | { |
1002 | ssize_t res = vfs_read(file, (void __user *)addr, len, &pos); |
1003 | if (res > 0) |
1004 | flush_icache_range(addr, addr + len); |
1005 | return res; |
1006 | } |
1007 | EXPORT_SYMBOL(read_code); |
1008 | |
1009 | static int exec_mmap(struct mm_struct *mm) |
1010 | { |
1011 | struct task_struct *tsk; |
1012 | struct mm_struct *old_mm, *active_mm; |
1013 | |
1014 | /* Notify parent that we're no longer interested in the old VM */ |
1015 | tsk = current; |
1016 | old_mm = current->mm; |
1017 | mm_release(tsk, old_mm); |
1018 | |
1019 | if (old_mm) { |
1020 | sync_mm_rss(old_mm); |
1021 | /* |
1022 | * Make sure that if there is a core dump in progress |
1023 | * for the old mm, we get out and die instead of going |
1024 | * through with the exec. We must hold mmap_sem around |
1025 | * checking core_state and changing tsk->mm. |
1026 | */ |
1027 | down_read(&old_mm->mmap_sem); |
1028 | if (unlikely(old_mm->core_state)) { |
1029 | up_read(&old_mm->mmap_sem); |
1030 | return -EINTR; |
1031 | } |
1032 | } |
1033 | task_lock(tsk); |
1034 | active_mm = tsk->active_mm; |
1035 | tsk->mm = mm; |
1036 | tsk->active_mm = mm; |
1037 | activate_mm(active_mm, mm); |
1038 | tsk->mm->vmacache_seqnum = 0; |
1039 | vmacache_flush(tsk); |
1040 | task_unlock(tsk); |
1041 | if (old_mm) { |
1042 | up_read(&old_mm->mmap_sem); |
1043 | BUG_ON(active_mm != old_mm); |
1044 | setmax_mm_hiwater_rss(&tsk->signal->maxrss, old_mm); |
1045 | mm_update_next_owner(old_mm); |
1046 | mmput(old_mm); |
1047 | return 0; |
1048 | } |
1049 | mmdrop(active_mm); |
1050 | return 0; |
1051 | } |
1052 | |
1053 | /* |
1054 | * This function makes sure the current process has its own signal table, |
1055 | * so that flush_signal_handlers can later reset the handlers without |
1056 | * disturbing other processes. (Other processes might share the signal |
1057 | * table via the CLONE_SIGHAND option to clone().) |
1058 | */ |
1059 | static int de_thread(struct task_struct *tsk) |
1060 | { |
1061 | struct signal_struct *sig = tsk->signal; |
1062 | struct sighand_struct *oldsighand = tsk->sighand; |
1063 | spinlock_t *lock = &oldsighand->siglock; |
1064 | |
1065 | if (thread_group_empty(tsk)) |
1066 | goto no_thread_group; |
1067 | |
1068 | /* |
1069 | * Kill all other threads in the thread group. |
1070 | */ |
1071 | spin_lock_irq(lock); |
1072 | if (signal_group_exit(sig)) { |
1073 | /* |
1074 | * Another group action in progress, just |
1075 | * return so that the signal is processed. |
1076 | */ |
1077 | spin_unlock_irq(lock); |
1078 | return -EAGAIN; |
1079 | } |
1080 | |
1081 | sig->group_exit_task = tsk; |
1082 | sig->notify_count = zap_other_threads(tsk); |
1083 | if (!thread_group_leader(tsk)) |
1084 | sig->notify_count--; |
1085 | |
1086 | while (sig->notify_count) { |
1087 | __set_current_state(TASK_KILLABLE); |
1088 | spin_unlock_irq(lock); |
1089 | schedule(); |
1090 | if (__fatal_signal_pending(tsk)) |
1091 | goto killed; |
1092 | spin_lock_irq(lock); |
1093 | } |
1094 | spin_unlock_irq(lock); |
1095 | |
1096 | /* |
1097 | * At this point all other threads have exited, all we have to |
1098 | * do is to wait for the thread group leader to become inactive, |
1099 | * and to assume its PID: |
1100 | */ |
1101 | if (!thread_group_leader(tsk)) { |
1102 | struct task_struct *leader = tsk->group_leader; |
1103 | |
1104 | for (;;) { |
1105 | cgroup_threadgroup_change_begin(tsk); |
1106 | write_lock_irq(&tasklist_lock); |
1107 | /* |
1108 | * Do this under tasklist_lock to ensure that |
1109 | * exit_notify() can't miss ->group_exit_task |
1110 | */ |
1111 | sig->notify_count = -1; |
1112 | if (likely(leader->exit_state)) |
1113 | break; |
1114 | __set_current_state(TASK_KILLABLE); |
1115 | write_unlock_irq(&tasklist_lock); |
1116 | cgroup_threadgroup_change_end(tsk); |
1117 | schedule(); |
1118 | if (__fatal_signal_pending(tsk)) |
1119 | goto killed; |
1120 | } |
1121 | |
1122 | /* |
1123 | * The only record we have of the real-time age of a |
1124 | * process, regardless of execs it's done, is start_time. |
1125 | * All the past CPU time is accumulated in signal_struct |
1126 | * from sister threads now dead. But in this non-leader |
1127 | * exec, nothing survives from the original leader thread, |
1128 | * whose birth marks the true age of this process now. |
1129 | * When we take on its identity by switching to its PID, we |
1130 | * also take its birthdate (always earlier than our own). |
1131 | */ |
1132 | tsk->start_time = leader->start_time; |
1133 | tsk->real_start_time = leader->real_start_time; |
1134 | |
1135 | BUG_ON(!same_thread_group(leader, tsk)); |
1136 | BUG_ON(has_group_leader_pid(tsk)); |
1137 | /* |
1138 | * An exec() starts a new thread group with the |
1139 | * TGID of the previous thread group. Rehash the |
1140 | * two threads with a switched PID, and release |
1141 | * the former thread group leader: |
1142 | */ |
1143 | |
1144 | /* Become a process group leader with the old leader's pid. |
1145 | * The old leader becomes a thread of the this thread group. |
1146 | * Note: The old leader also uses this pid until release_task |
1147 | * is called. Odd but simple and correct. |
1148 | */ |
1149 | tsk->pid = leader->pid; |
1150 | change_pid(tsk, PIDTYPE_PID, task_pid(leader)); |
1151 | transfer_pid(leader, tsk, PIDTYPE_TGID); |
1152 | transfer_pid(leader, tsk, PIDTYPE_PGID); |
1153 | transfer_pid(leader, tsk, PIDTYPE_SID); |
1154 | |
1155 | list_replace_rcu(&leader->tasks, &tsk->tasks); |
1156 | list_replace_init(&leader->sibling, &tsk->sibling); |
1157 | |
1158 | tsk->group_leader = tsk; |
1159 | leader->group_leader = tsk; |
1160 | |
1161 | tsk->exit_signal = SIGCHLD; |
1162 | leader->exit_signal = -1; |
1163 | |
1164 | BUG_ON(leader->exit_state != EXIT_ZOMBIE); |
1165 | leader->exit_state = EXIT_DEAD; |
1166 | |
1167 | /* |
1168 | * We are going to release_task()->ptrace_unlink() silently, |
1169 | * the tracer can sleep in do_wait(). EXIT_DEAD guarantees |
1170 | * the tracer wont't block again waiting for this thread. |
1171 | */ |
1172 | if (unlikely(leader->ptrace)) |
1173 | __wake_up_parent(leader, leader->parent); |
1174 | write_unlock_irq(&tasklist_lock); |
1175 | cgroup_threadgroup_change_end(tsk); |
1176 | |
1177 | release_task(leader); |
1178 | } |
1179 | |
1180 | sig->group_exit_task = NULL; |
1181 | sig->notify_count = 0; |
1182 | |
1183 | no_thread_group: |
1184 | /* we have changed execution domain */ |
1185 | tsk->exit_signal = SIGCHLD; |
1186 | |
1187 | #ifdef CONFIG_POSIX_TIMERS |
1188 | exit_itimers(sig); |
1189 | flush_itimer_signals(); |
1190 | #endif |
1191 | |
1192 | if (refcount_read(&oldsighand->count) != 1) { |
1193 | struct sighand_struct *newsighand; |
1194 | /* |
1195 | * This ->sighand is shared with the CLONE_SIGHAND |
1196 | * but not CLONE_THREAD task, switch to the new one. |
1197 | */ |
1198 | newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL); |
1199 | if (!newsighand) |
1200 | return -ENOMEM; |
1201 | |
1202 | refcount_set(&newsighand->count, 1); |
1203 | memcpy(newsighand->action, oldsighand->action, |
1204 | sizeof(newsighand->action)); |
1205 | |
1206 | write_lock_irq(&tasklist_lock); |
1207 | spin_lock(&oldsighand->siglock); |
1208 | rcu_assign_pointer(tsk->sighand, newsighand); |
1209 | spin_unlock(&oldsighand->siglock); |
1210 | write_unlock_irq(&tasklist_lock); |
1211 | |
1212 | __cleanup_sighand(oldsighand); |
1213 | } |
1214 | |
1215 | BUG_ON(!thread_group_leader(tsk)); |
1216 | return 0; |
1217 | |
1218 | killed: |
1219 | /* protects against exit_notify() and __exit_signal() */ |
1220 | read_lock(&tasklist_lock); |
1221 | sig->group_exit_task = NULL; |
1222 | sig->notify_count = 0; |
1223 | read_unlock(&tasklist_lock); |
1224 | return -EAGAIN; |
1225 | } |
1226 | |
1227 | char *__get_task_comm(char *buf, size_t buf_size, struct task_struct *tsk) |
1228 | { |
1229 | task_lock(tsk); |
1230 | strncpy(buf, tsk->comm, buf_size); |
1231 | task_unlock(tsk); |
1232 | return buf; |
1233 | } |
1234 | EXPORT_SYMBOL_GPL(__get_task_comm); |
1235 | |
1236 | /* |
1237 | * These functions flushes out all traces of the currently running executable |
1238 | * so that a new one can be started |
1239 | */ |
1240 | |
1241 | void __set_task_comm(struct task_struct *tsk, const char *buf, bool exec) |
1242 | { |
1243 | task_lock(tsk); |
1244 | trace_task_rename(tsk, buf); |
1245 | strlcpy(tsk->comm, buf, sizeof(tsk->comm)); |
1246 | task_unlock(tsk); |
1247 | perf_event_comm(tsk, exec); |
1248 | } |
1249 | |
1250 | /* |
1251 | * Calling this is the point of no return. None of the failures will be |
1252 | * seen by userspace since either the process is already taking a fatal |
1253 | * signal (via de_thread() or coredump), or will have SEGV raised |
1254 | * (after exec_mmap()) by search_binary_handlers (see below). |
1255 | */ |
1256 | int flush_old_exec(struct linux_binprm * bprm) |
1257 | { |
1258 | int retval; |
1259 | |
1260 | /* |
1261 | * Make sure we have a private signal table and that |
1262 | * we are unassociated from the previous thread group. |
1263 | */ |
1264 | retval = de_thread(current); |
1265 | if (retval) |
1266 | goto out; |
1267 | |
1268 | /* |
1269 | * Must be called _before_ exec_mmap() as bprm->mm is |
1270 | * not visibile until then. This also enables the update |
1271 | * to be lockless. |
1272 | */ |
1273 | set_mm_exe_file(bprm->mm, bprm->file); |
1274 | |
1275 | /* |
1276 | * Release all of the old mmap stuff |
1277 | */ |
1278 | acct_arg_size(bprm, 0); |
1279 | retval = exec_mmap(bprm->mm); |
1280 | if (retval) |
1281 | goto out; |
1282 | |
1283 | /* |
1284 | * After clearing bprm->mm (to mark that current is using the |
1285 | * prepared mm now), we have nothing left of the original |
1286 | * process. If anything from here on returns an error, the check |
1287 | * in search_binary_handler() will SEGV current. |
1288 | */ |
1289 | bprm->mm = NULL; |
1290 | |
1291 | set_fs(USER_DS); |
1292 | current->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD | |
1293 | PF_NOFREEZE | PF_NO_SETAFFINITY); |
1294 | flush_thread(); |
1295 | current->personality &= ~bprm->per_clear; |
1296 | |
1297 | /* |
1298 | * We have to apply CLOEXEC before we change whether the process is |
1299 | * dumpable (in setup_new_exec) to avoid a race with a process in userspace |
1300 | * trying to access the should-be-closed file descriptors of a process |
1301 | * undergoing exec(2). |
1302 | */ |
1303 | do_close_on_exec(current->files); |
1304 | return 0; |
1305 | |
1306 | out: |
1307 | return retval; |
1308 | } |
1309 | EXPORT_SYMBOL(flush_old_exec); |
1310 | |
1311 | void would_dump(struct linux_binprm *bprm, struct file *file) |
1312 | { |
1313 | struct inode *inode = file_inode(file); |
1314 | if (inode_permission(inode, MAY_READ) < 0) { |
1315 | struct user_namespace *old, *user_ns; |
1316 | bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; |
1317 | |
1318 | /* Ensure mm->user_ns contains the executable */ |
1319 | user_ns = old = bprm->mm->user_ns; |
1320 | while ((user_ns != &init_user_ns) && |
1321 | !privileged_wrt_inode_uidgid(user_ns, inode)) |
1322 | user_ns = user_ns->parent; |
1323 | |
1324 | if (old != user_ns) { |
1325 | bprm->mm->user_ns = get_user_ns(user_ns); |
1326 | put_user_ns(old); |
1327 | } |
1328 | } |
1329 | } |
1330 | EXPORT_SYMBOL(would_dump); |
1331 | |
1332 | void setup_new_exec(struct linux_binprm * bprm) |
1333 | { |
1334 | /* |
1335 | * Once here, prepare_binrpm() will not be called any more, so |
1336 | * the final state of setuid/setgid/fscaps can be merged into the |
1337 | * secureexec flag. |
1338 | */ |
1339 | bprm->secureexec |= bprm->cap_elevated; |
1340 | |
1341 | if (bprm->secureexec) { |
1342 | /* Make sure parent cannot signal privileged process. */ |
1343 | current->pdeath_signal = 0; |
1344 | |
1345 | /* |
1346 | * For secureexec, reset the stack limit to sane default to |
1347 | * avoid bad behavior from the prior rlimits. This has to |
1348 | * happen before arch_pick_mmap_layout(), which examines |
1349 | * RLIMIT_STACK, but after the point of no return to avoid |
1350 | * needing to clean up the change on failure. |
1351 | */ |
1352 | if (bprm->rlim_stack.rlim_cur > _STK_LIM) |
1353 | bprm->rlim_stack.rlim_cur = _STK_LIM; |
1354 | } |
1355 | |
1356 | arch_pick_mmap_layout(current->mm, &bprm->rlim_stack); |
1357 | |
1358 | current->sas_ss_sp = current->sas_ss_size = 0; |
1359 | |
1360 | /* |
1361 | * Figure out dumpability. Note that this checking only of current |
1362 | * is wrong, but userspace depends on it. This should be testing |
1363 | * bprm->secureexec instead. |
1364 | */ |
1365 | if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP || |
1366 | !(uid_eq(current_euid(), current_uid()) && |
1367 | gid_eq(current_egid(), current_gid()))) |
1368 | set_dumpable(current->mm, suid_dumpable); |
1369 | else |
1370 | set_dumpable(current->mm, SUID_DUMP_USER); |
1371 | |
1372 | arch_setup_new_exec(); |
1373 | perf_event_exec(); |
1374 | __set_task_comm(current, kbasename(bprm->filename), true); |
1375 | |
1376 | /* Set the new mm task size. We have to do that late because it may |
1377 | * depend on TIF_32BIT which is only updated in flush_thread() on |
1378 | * some architectures like powerpc |
1379 | */ |
1380 | current->mm->task_size = TASK_SIZE; |
1381 | |
1382 | /* An exec changes our domain. We are no longer part of the thread |
1383 | group */ |
1384 | current->self_exec_id++; |
1385 | flush_signal_handlers(current, 0); |
1386 | } |
1387 | EXPORT_SYMBOL(setup_new_exec); |
1388 | |
1389 | /* Runs immediately before start_thread() takes over. */ |
1390 | void finalize_exec(struct linux_binprm *bprm) |
1391 | { |
1392 | /* Store any stack rlimit changes before starting thread. */ |
1393 | task_lock(current->group_leader); |
1394 | current->signal->rlim[RLIMIT_STACK] = bprm->rlim_stack; |
1395 | task_unlock(current->group_leader); |
1396 | } |
1397 | EXPORT_SYMBOL(finalize_exec); |
1398 | |
1399 | /* |
1400 | * Prepare credentials and lock ->cred_guard_mutex. |
1401 | * install_exec_creds() commits the new creds and drops the lock. |
1402 | * Or, if exec fails before, free_bprm() should release ->cred and |
1403 | * and unlock. |
1404 | */ |
1405 | static int prepare_bprm_creds(struct linux_binprm *bprm) |
1406 | { |
1407 | if (mutex_lock_interruptible(¤t->signal->cred_guard_mutex)) |
1408 | return -ERESTARTNOINTR; |
1409 | |
1410 | bprm->cred = prepare_exec_creds(); |
1411 | if (likely(bprm->cred)) |
1412 | return 0; |
1413 | |
1414 | mutex_unlock(¤t->signal->cred_guard_mutex); |
1415 | return -ENOMEM; |
1416 | } |
1417 | |
1418 | static void free_bprm(struct linux_binprm *bprm) |
1419 | { |
1420 | free_arg_pages(bprm); |
1421 | if (bprm->cred) { |
1422 | mutex_unlock(¤t->signal->cred_guard_mutex); |
1423 | abort_creds(bprm->cred); |
1424 | } |
1425 | if (bprm->file) { |
1426 | allow_write_access(bprm->file); |
1427 | fput(bprm->file); |
1428 | } |
1429 | /* If a binfmt changed the interp, free it. */ |
1430 | if (bprm->interp != bprm->filename) |
1431 | kfree(bprm->interp); |
1432 | kfree(bprm); |
1433 | } |
1434 | |
1435 | int bprm_change_interp(const char *interp, struct linux_binprm *bprm) |
1436 | { |
1437 | /* If a binfmt changed the interp, free it first. */ |
1438 | if (bprm->interp != bprm->filename) |
1439 | kfree(bprm->interp); |
1440 | bprm->interp = kstrdup(interp, GFP_KERNEL); |
1441 | if (!bprm->interp) |
1442 | return -ENOMEM; |
1443 | return 0; |
1444 | } |
1445 | EXPORT_SYMBOL(bprm_change_interp); |
1446 | |
1447 | /* |
1448 | * install the new credentials for this executable |
1449 | */ |
1450 | void install_exec_creds(struct linux_binprm *bprm) |
1451 | { |
1452 | security_bprm_committing_creds(bprm); |
1453 | |
1454 | commit_creds(bprm->cred); |
1455 | bprm->cred = NULL; |
1456 | |
1457 | /* |
1458 | * Disable monitoring for regular users |
1459 | * when executing setuid binaries. Must |
1460 | * wait until new credentials are committed |
1461 | * by commit_creds() above |
1462 | */ |
1463 | if (get_dumpable(current->mm) != SUID_DUMP_USER) |
1464 | perf_event_exit_task(current); |
1465 | /* |
1466 | * cred_guard_mutex must be held at least to this point to prevent |
1467 | * ptrace_attach() from altering our determination of the task's |
1468 | * credentials; any time after this it may be unlocked. |
1469 | */ |
1470 | security_bprm_committed_creds(bprm); |
1471 | mutex_unlock(¤t->signal->cred_guard_mutex); |
1472 | } |
1473 | EXPORT_SYMBOL(install_exec_creds); |
1474 | |
1475 | /* |
1476 | * determine how safe it is to execute the proposed program |
1477 | * - the caller must hold ->cred_guard_mutex to protect against |
1478 | * PTRACE_ATTACH or seccomp thread-sync |
1479 | */ |
1480 | static void check_unsafe_exec(struct linux_binprm *bprm) |
1481 | { |
1482 | struct task_struct *p = current, *t; |
1483 | unsigned n_fs; |
1484 | |
1485 | if (p->ptrace) |
1486 | bprm->unsafe |= LSM_UNSAFE_PTRACE; |
1487 | |
1488 | /* |
1489 | * This isn't strictly necessary, but it makes it harder for LSMs to |
1490 | * mess up. |
1491 | */ |
1492 | if (task_no_new_privs(current)) |
1493 | bprm->unsafe |= LSM_UNSAFE_NO_NEW_PRIVS; |
1494 | |
1495 | t = p; |
1496 | n_fs = 1; |
1497 | spin_lock(&p->fs->lock); |
1498 | rcu_read_lock(); |
1499 | while_each_thread(p, t) { |
1500 | if (t->fs == p->fs) |
1501 | n_fs++; |
1502 | } |
1503 | rcu_read_unlock(); |
1504 | |
1505 | if (p->fs->users > n_fs) |
1506 | bprm->unsafe |= LSM_UNSAFE_SHARE; |
1507 | else |
1508 | p->fs->in_exec = 1; |
1509 | spin_unlock(&p->fs->lock); |
1510 | } |
1511 | |
1512 | static void bprm_fill_uid(struct linux_binprm *bprm) |
1513 | { |
1514 | struct inode *inode; |
1515 | unsigned int mode; |
1516 | kuid_t uid; |
1517 | kgid_t gid; |
1518 | |
1519 | /* |
1520 | * Since this can be called multiple times (via prepare_binprm), |
1521 | * we must clear any previous work done when setting set[ug]id |
1522 | * bits from any earlier bprm->file uses (for example when run |
1523 | * first for a setuid script then again for its interpreter). |
1524 | */ |
1525 | bprm->cred->euid = current_euid(); |
1526 | bprm->cred->egid = current_egid(); |
1527 | |
1528 | if (!mnt_may_suid(bprm->file->f_path.mnt)) |
1529 | return; |
1530 | |
1531 | if (task_no_new_privs(current)) |
1532 | return; |
1533 | |
1534 | inode = bprm->file->f_path.dentry->d_inode; |
1535 | mode = READ_ONCE(inode->i_mode); |
1536 | if (!(mode & (S_ISUID|S_ISGID))) |
1537 | return; |
1538 | |
1539 | /* Be careful if suid/sgid is set */ |
1540 | inode_lock(inode); |
1541 | |
1542 | /* reload atomically mode/uid/gid now that lock held */ |
1543 | mode = inode->i_mode; |
1544 | uid = inode->i_uid; |
1545 | gid = inode->i_gid; |
1546 | inode_unlock(inode); |
1547 | |
1548 | /* We ignore suid/sgid if there are no mappings for them in the ns */ |
1549 | if (!kuid_has_mapping(bprm->cred->user_ns, uid) || |
1550 | !kgid_has_mapping(bprm->cred->user_ns, gid)) |
1551 | return; |
1552 | |
1553 | if (mode & S_ISUID) { |
1554 | bprm->per_clear |= PER_CLEAR_ON_SETID; |
1555 | bprm->cred->euid = uid; |
1556 | } |
1557 | |
1558 | if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { |
1559 | bprm->per_clear |= PER_CLEAR_ON_SETID; |
1560 | bprm->cred->egid = gid; |
1561 | } |
1562 | } |
1563 | |
1564 | /* |
1565 | * Fill the binprm structure from the inode. |
1566 | * Check permissions, then read the first BINPRM_BUF_SIZE bytes |
1567 | * |
1568 | * This may be called multiple times for binary chains (scripts for example). |
1569 | */ |
1570 | int prepare_binprm(struct linux_binprm *bprm) |
1571 | { |
1572 | int retval; |
1573 | loff_t pos = 0; |
1574 | |
1575 | bprm_fill_uid(bprm); |
1576 | |
1577 | /* fill in binprm security blob */ |
1578 | retval = security_bprm_set_creds(bprm); |
1579 | if (retval) |
1580 | return retval; |
1581 | bprm->called_set_creds = 1; |
1582 | |
1583 | memset(bprm->buf, 0, BINPRM_BUF_SIZE); |
1584 | return kernel_read(bprm->file, bprm->buf, BINPRM_BUF_SIZE, &pos); |
1585 | } |
1586 | |
1587 | EXPORT_SYMBOL(prepare_binprm); |
1588 | |
1589 | /* |
1590 | * Arguments are '\0' separated strings found at the location bprm->p |
1591 | * points to; chop off the first by relocating brpm->p to right after |
1592 | * the first '\0' encountered. |
1593 | */ |
1594 | int remove_arg_zero(struct linux_binprm *bprm) |
1595 | { |
1596 | int ret = 0; |
1597 | unsigned long offset; |
1598 | char *kaddr; |
1599 | struct page *page; |
1600 | |
1601 | if (!bprm->argc) |
1602 | return 0; |
1603 | |
1604 | do { |
1605 | offset = bprm->p & ~PAGE_MASK; |
1606 | page = get_arg_page(bprm, bprm->p, 0); |
1607 | if (!page) { |
1608 | ret = -EFAULT; |
1609 | goto out; |
1610 | } |
1611 | kaddr = kmap_atomic(page); |
1612 | |
1613 | for (; offset < PAGE_SIZE && kaddr[offset]; |
1614 | offset++, bprm->p++) |
1615 | ; |
1616 | |
1617 | kunmap_atomic(kaddr); |
1618 | put_arg_page(page); |
1619 | } while (offset == PAGE_SIZE); |
1620 | |
1621 | bprm->p++; |
1622 | bprm->argc--; |
1623 | ret = 0; |
1624 | |
1625 | out: |
1626 | return ret; |
1627 | } |
1628 | EXPORT_SYMBOL(remove_arg_zero); |
1629 | |
1630 | #define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e)) |
1631 | /* |
1632 | * cycle the list of binary formats handler, until one recognizes the image |
1633 | */ |
1634 | int search_binary_handler(struct linux_binprm *bprm) |
1635 | { |
1636 | bool need_retry = IS_ENABLED(CONFIG_MODULES); |
1637 | struct linux_binfmt *fmt; |
1638 | int retval; |
1639 | |
1640 | /* This allows 4 levels of binfmt rewrites before failing hard. */ |
1641 | if (bprm->recursion_depth > 5) |
1642 | return -ELOOP; |
1643 | |
1644 | retval = security_bprm_check(bprm); |
1645 | if (retval) |
1646 | return retval; |
1647 | |
1648 | retval = -ENOENT; |
1649 | retry: |
1650 | read_lock(&binfmt_lock); |
1651 | list_for_each_entry(fmt, &formats, lh) { |
1652 | if (!try_module_get(fmt->module)) |
1653 | continue; |
1654 | read_unlock(&binfmt_lock); |
1655 | bprm->recursion_depth++; |
1656 | retval = fmt->load_binary(bprm); |
1657 | read_lock(&binfmt_lock); |
1658 | put_binfmt(fmt); |
1659 | bprm->recursion_depth--; |
1660 | if (retval < 0 && !bprm->mm) { |
1661 | /* we got to flush_old_exec() and failed after it */ |
1662 | read_unlock(&binfmt_lock); |
1663 | force_sigsegv(SIGSEGV, current); |
1664 | return retval; |
1665 | } |
1666 | if (retval != -ENOEXEC || !bprm->file) { |
1667 | read_unlock(&binfmt_lock); |
1668 | return retval; |
1669 | } |
1670 | } |
1671 | read_unlock(&binfmt_lock); |
1672 | |
1673 | if (need_retry) { |
1674 | if (printable(bprm->buf[0]) && printable(bprm->buf[1]) && |
1675 | printable(bprm->buf[2]) && printable(bprm->buf[3])) |
1676 | return retval; |
1677 | if (request_module("binfmt-%04x" , *(ushort *)(bprm->buf + 2)) < 0) |
1678 | return retval; |
1679 | need_retry = false; |
1680 | goto retry; |
1681 | } |
1682 | |
1683 | return retval; |
1684 | } |
1685 | EXPORT_SYMBOL(search_binary_handler); |
1686 | |
1687 | static int exec_binprm(struct linux_binprm *bprm) |
1688 | { |
1689 | pid_t old_pid, old_vpid; |
1690 | int ret; |
1691 | |
1692 | /* Need to fetch pid before load_binary changes it */ |
1693 | old_pid = current->pid; |
1694 | rcu_read_lock(); |
1695 | old_vpid = task_pid_nr_ns(current, task_active_pid_ns(current->parent)); |
1696 | rcu_read_unlock(); |
1697 | |
1698 | ret = search_binary_handler(bprm); |
1699 | if (ret >= 0) { |
1700 | audit_bprm(bprm); |
1701 | trace_sched_process_exec(current, old_pid, bprm); |
1702 | ptrace_event(PTRACE_EVENT_EXEC, old_vpid); |
1703 | proc_exec_connector(current); |
1704 | } |
1705 | |
1706 | return ret; |
1707 | } |
1708 | |
1709 | /* |
1710 | * sys_execve() executes a new program. |
1711 | */ |
1712 | static int __do_execve_file(int fd, struct filename *filename, |
1713 | struct user_arg_ptr argv, |
1714 | struct user_arg_ptr envp, |
1715 | int flags, struct file *file) |
1716 | { |
1717 | char *pathbuf = NULL; |
1718 | struct linux_binprm *bprm; |
1719 | struct files_struct *displaced; |
1720 | int retval; |
1721 | |
1722 | if (IS_ERR(filename)) |
1723 | return PTR_ERR(filename); |
1724 | |
1725 | /* |
1726 | * We move the actual failure in case of RLIMIT_NPROC excess from |
1727 | * set*uid() to execve() because too many poorly written programs |
1728 | * don't check setuid() return code. Here we additionally recheck |
1729 | * whether NPROC limit is still exceeded. |
1730 | */ |
1731 | if ((current->flags & PF_NPROC_EXCEEDED) && |
1732 | atomic_read(¤t_user()->processes) > rlimit(RLIMIT_NPROC)) { |
1733 | retval = -EAGAIN; |
1734 | goto out_ret; |
1735 | } |
1736 | |
1737 | /* We're below the limit (still or again), so we don't want to make |
1738 | * further execve() calls fail. */ |
1739 | current->flags &= ~PF_NPROC_EXCEEDED; |
1740 | |
1741 | retval = unshare_files(&displaced); |
1742 | if (retval) |
1743 | goto out_ret; |
1744 | |
1745 | retval = -ENOMEM; |
1746 | bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); |
1747 | if (!bprm) |
1748 | goto out_files; |
1749 | |
1750 | retval = prepare_bprm_creds(bprm); |
1751 | if (retval) |
1752 | goto out_free; |
1753 | |
1754 | check_unsafe_exec(bprm); |
1755 | current->in_execve = 1; |
1756 | |
1757 | if (!file) |
1758 | file = do_open_execat(fd, filename, flags); |
1759 | retval = PTR_ERR(file); |
1760 | if (IS_ERR(file)) |
1761 | goto out_unmark; |
1762 | |
1763 | sched_exec(); |
1764 | |
1765 | bprm->file = file; |
1766 | if (!filename) { |
1767 | bprm->filename = "none" ; |
1768 | } else if (fd == AT_FDCWD || filename->name[0] == '/') { |
1769 | bprm->filename = filename->name; |
1770 | } else { |
1771 | if (filename->name[0] == '\0') |
1772 | pathbuf = kasprintf(GFP_KERNEL, "/dev/fd/%d" , fd); |
1773 | else |
1774 | pathbuf = kasprintf(GFP_KERNEL, "/dev/fd/%d/%s" , |
1775 | fd, filename->name); |
1776 | if (!pathbuf) { |
1777 | retval = -ENOMEM; |
1778 | goto out_unmark; |
1779 | } |
1780 | /* |
1781 | * Record that a name derived from an O_CLOEXEC fd will be |
1782 | * inaccessible after exec. Relies on having exclusive access to |
1783 | * current->files (due to unshare_files above). |
1784 | */ |
1785 | if (close_on_exec(fd, rcu_dereference_raw(current->files->fdt))) |
1786 | bprm->interp_flags |= BINPRM_FLAGS_PATH_INACCESSIBLE; |
1787 | bprm->filename = pathbuf; |
1788 | } |
1789 | bprm->interp = bprm->filename; |
1790 | |
1791 | retval = bprm_mm_init(bprm); |
1792 | if (retval) |
1793 | goto out_unmark; |
1794 | |
1795 | retval = prepare_arg_pages(bprm, argv, envp); |
1796 | if (retval < 0) |
1797 | goto out; |
1798 | |
1799 | retval = prepare_binprm(bprm); |
1800 | if (retval < 0) |
1801 | goto out; |
1802 | |
1803 | retval = copy_strings_kernel(1, &bprm->filename, bprm); |
1804 | if (retval < 0) |
1805 | goto out; |
1806 | |
1807 | bprm->exec = bprm->p; |
1808 | retval = copy_strings(bprm->envc, envp, bprm); |
1809 | if (retval < 0) |
1810 | goto out; |
1811 | |
1812 | retval = copy_strings(bprm->argc, argv, bprm); |
1813 | if (retval < 0) |
1814 | goto out; |
1815 | |
1816 | would_dump(bprm, bprm->file); |
1817 | |
1818 | retval = exec_binprm(bprm); |
1819 | if (retval < 0) |
1820 | goto out; |
1821 | |
1822 | /* execve succeeded */ |
1823 | current->fs->in_exec = 0; |
1824 | current->in_execve = 0; |
1825 | membarrier_execve(current); |
1826 | rseq_execve(current); |
1827 | acct_update_integrals(current); |
1828 | task_numa_free(current); |
1829 | free_bprm(bprm); |
1830 | kfree(pathbuf); |
1831 | if (filename) |
1832 | putname(filename); |
1833 | if (displaced) |
1834 | put_files_struct(displaced); |
1835 | return retval; |
1836 | |
1837 | out: |
1838 | if (bprm->mm) { |
1839 | acct_arg_size(bprm, 0); |
1840 | mmput(bprm->mm); |
1841 | } |
1842 | |
1843 | out_unmark: |
1844 | current->fs->in_exec = 0; |
1845 | current->in_execve = 0; |
1846 | |
1847 | out_free: |
1848 | free_bprm(bprm); |
1849 | kfree(pathbuf); |
1850 | |
1851 | out_files: |
1852 | if (displaced) |
1853 | reset_files_struct(displaced); |
1854 | out_ret: |
1855 | if (filename) |
1856 | putname(filename); |
1857 | return retval; |
1858 | } |
1859 | |
1860 | static int do_execveat_common(int fd, struct filename *filename, |
1861 | struct user_arg_ptr argv, |
1862 | struct user_arg_ptr envp, |
1863 | int flags) |
1864 | { |
1865 | return __do_execve_file(fd, filename, argv, envp, flags, NULL); |
1866 | } |
1867 | |
1868 | int do_execve_file(struct file *file, void *__argv, void *__envp) |
1869 | { |
1870 | struct user_arg_ptr argv = { .ptr.native = __argv }; |
1871 | struct user_arg_ptr envp = { .ptr.native = __envp }; |
1872 | |
1873 | return __do_execve_file(AT_FDCWD, NULL, argv, envp, 0, file); |
1874 | } |
1875 | |
1876 | int do_execve(struct filename *filename, |
1877 | const char __user *const __user *__argv, |
1878 | const char __user *const __user *__envp) |
1879 | { |
1880 | struct user_arg_ptr argv = { .ptr.native = __argv }; |
1881 | struct user_arg_ptr envp = { .ptr.native = __envp }; |
1882 | return do_execveat_common(AT_FDCWD, filename, argv, envp, 0); |
1883 | } |
1884 | |
1885 | int do_execveat(int fd, struct filename *filename, |
1886 | const char __user *const __user *__argv, |
1887 | const char __user *const __user *__envp, |
1888 | int flags) |
1889 | { |
1890 | struct user_arg_ptr argv = { .ptr.native = __argv }; |
1891 | struct user_arg_ptr envp = { .ptr.native = __envp }; |
1892 | |
1893 | return do_execveat_common(fd, filename, argv, envp, flags); |
1894 | } |
1895 | |
1896 | #ifdef CONFIG_COMPAT |
1897 | static int compat_do_execve(struct filename *filename, |
1898 | const compat_uptr_t __user *__argv, |
1899 | const compat_uptr_t __user *__envp) |
1900 | { |
1901 | struct user_arg_ptr argv = { |
1902 | .is_compat = true, |
1903 | .ptr.compat = __argv, |
1904 | }; |
1905 | struct user_arg_ptr envp = { |
1906 | .is_compat = true, |
1907 | .ptr.compat = __envp, |
1908 | }; |
1909 | return do_execveat_common(AT_FDCWD, filename, argv, envp, 0); |
1910 | } |
1911 | |
1912 | static int compat_do_execveat(int fd, struct filename *filename, |
1913 | const compat_uptr_t __user *__argv, |
1914 | const compat_uptr_t __user *__envp, |
1915 | int flags) |
1916 | { |
1917 | struct user_arg_ptr argv = { |
1918 | .is_compat = true, |
1919 | .ptr.compat = __argv, |
1920 | }; |
1921 | struct user_arg_ptr envp = { |
1922 | .is_compat = true, |
1923 | .ptr.compat = __envp, |
1924 | }; |
1925 | return do_execveat_common(fd, filename, argv, envp, flags); |
1926 | } |
1927 | #endif |
1928 | |
1929 | void set_binfmt(struct linux_binfmt *new) |
1930 | { |
1931 | struct mm_struct *mm = current->mm; |
1932 | |
1933 | if (mm->binfmt) |
1934 | module_put(mm->binfmt->module); |
1935 | |
1936 | mm->binfmt = new; |
1937 | if (new) |
1938 | __module_get(new->module); |
1939 | } |
1940 | EXPORT_SYMBOL(set_binfmt); |
1941 | |
1942 | /* |
1943 | * set_dumpable stores three-value SUID_DUMP_* into mm->flags. |
1944 | */ |
1945 | void set_dumpable(struct mm_struct *mm, int value) |
1946 | { |
1947 | if (WARN_ON((unsigned)value > SUID_DUMP_ROOT)) |
1948 | return; |
1949 | |
1950 | set_mask_bits(&mm->flags, MMF_DUMPABLE_MASK, value); |
1951 | } |
1952 | |
1953 | SYSCALL_DEFINE3(execve, |
1954 | const char __user *, filename, |
1955 | const char __user *const __user *, argv, |
1956 | const char __user *const __user *, envp) |
1957 | { |
1958 | return do_execve(getname(filename), argv, envp); |
1959 | } |
1960 | |
1961 | SYSCALL_DEFINE5(execveat, |
1962 | int, fd, const char __user *, filename, |
1963 | const char __user *const __user *, argv, |
1964 | const char __user *const __user *, envp, |
1965 | int, flags) |
1966 | { |
1967 | int lookup_flags = (flags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0; |
1968 | |
1969 | return do_execveat(fd, |
1970 | getname_flags(filename, lookup_flags, NULL), |
1971 | argv, envp, flags); |
1972 | } |
1973 | |
1974 | #ifdef CONFIG_COMPAT |
1975 | COMPAT_SYSCALL_DEFINE3(execve, const char __user *, filename, |
1976 | const compat_uptr_t __user *, argv, |
1977 | const compat_uptr_t __user *, envp) |
1978 | { |
1979 | return compat_do_execve(getname(filename), argv, envp); |
1980 | } |
1981 | |
1982 | COMPAT_SYSCALL_DEFINE5(execveat, int, fd, |
1983 | const char __user *, filename, |
1984 | const compat_uptr_t __user *, argv, |
1985 | const compat_uptr_t __user *, envp, |
1986 | int, flags) |
1987 | { |
1988 | int lookup_flags = (flags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0; |
1989 | |
1990 | return compat_do_execveat(fd, |
1991 | getname_flags(filename, lookup_flags, NULL), |
1992 | argv, envp, flags); |
1993 | } |
1994 | #endif |
1995 | |