Commit | Line | Data |
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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * linux/fs/exec.c | |
4 | * | |
5 | * Copyright (C) 1991, 1992 Linus Torvalds | |
6 | */ | |
7 | ||
8 | /* | |
9 | * #!-checking implemented by tytso. | |
10 | */ | |
11 | /* | |
12 | * Demand-loading implemented 01.12.91 - no need to read anything but | |
13 | * the header into memory. The inode of the executable is put into | |
14 | * "current->executable", and page faults do the actual loading. Clean. | |
15 | * | |
16 | * Once more I can proudly say that linux stood up to being changed: it | |
17 | * was less than 2 hours work to get demand-loading completely implemented. | |
18 | * | |
19 | * Demand loading changed July 1993 by Eric Youngdale. Use mmap instead, | |
20 | * current->executable is only used by the procfs. This allows a dispatch | |
21 | * table to check for several different types of binary formats. We keep | |
22 | * trying until we recognize the file or we run out of supported binary | |
613cc2b6 | 23 | * formats. |
1da177e4 LT |
24 | */ |
25 | ||
1da177e4 LT |
26 | #include <linux/slab.h> |
27 | #include <linux/file.h> | |
9f3acc31 | 28 | #include <linux/fdtable.h> |
ba92a43d | 29 | #include <linux/mm.h> |
615d6e87 | 30 | #include <linux/vmacache.h> |
1da177e4 LT |
31 | #include <linux/stat.h> |
32 | #include <linux/fcntl.h> | |
ba92a43d | 33 | #include <linux/swap.h> |
74aadce9 | 34 | #include <linux/string.h> |
1da177e4 | 35 | #include <linux/init.h> |
6e84f315 | 36 | #include <linux/sched/mm.h> |
f7ccbae4 | 37 | #include <linux/sched/coredump.h> |
3f07c014 | 38 | #include <linux/sched/signal.h> |
6a3827d7 | 39 | #include <linux/sched/numa_balancing.h> |
29930025 | 40 | #include <linux/sched/task.h> |
ca5b172b | 41 | #include <linux/pagemap.h> |
cdd6c482 | 42 | #include <linux/perf_event.h> |
1da177e4 LT |
43 | #include <linux/highmem.h> |
44 | #include <linux/spinlock.h> | |
45 | #include <linux/key.h> | |
46 | #include <linux/personality.h> | |
47 | #include <linux/binfmts.h> | |
1da177e4 | 48 | #include <linux/utsname.h> |
84d73786 | 49 | #include <linux/pid_namespace.h> |
1da177e4 LT |
50 | #include <linux/module.h> |
51 | #include <linux/namei.h> | |
1da177e4 LT |
52 | #include <linux/mount.h> |
53 | #include <linux/security.h> | |
54 | #include <linux/syscalls.h> | |
8f0ab514 | 55 | #include <linux/tsacct_kern.h> |
9f46080c | 56 | #include <linux/cn_proc.h> |
473ae30b | 57 | #include <linux/audit.h> |
6341c393 | 58 | #include <linux/tracehook.h> |
5f4123be | 59 | #include <linux/kmod.h> |
6110e3ab | 60 | #include <linux/fsnotify.h> |
5ad4e53b | 61 | #include <linux/fs_struct.h> |
3d5992d2 | 62 | #include <linux/oom.h> |
0e028465 | 63 | #include <linux/compat.h> |
b44a7dfc | 64 | #include <linux/vmalloc.h> |
1da177e4 | 65 | |
7c0f6ba6 | 66 | #include <linux/uaccess.h> |
1da177e4 | 67 | #include <asm/mmu_context.h> |
b6a2fea3 | 68 | #include <asm/tlb.h> |
43d2b113 KH |
69 | |
70 | #include <trace/events/task.h> | |
a6f76f23 | 71 | #include "internal.h" |
1da177e4 | 72 | |
4ff16c25 DS |
73 | #include <trace/events/sched.h> |
74 | ||
56305aa9 EB |
75 | static int bprm_creds_from_file(struct linux_binprm *bprm); |
76 | ||
d6e71144 AC |
77 | int suid_dumpable = 0; |
78 | ||
e4dc1b14 | 79 | static LIST_HEAD(formats); |
1da177e4 LT |
80 | static DEFINE_RWLOCK(binfmt_lock); |
81 | ||
8fc3dc5a | 82 | void __register_binfmt(struct linux_binfmt * fmt, int insert) |
1da177e4 | 83 | { |
8fc3dc5a | 84 | BUG_ON(!fmt); |
92eaa565 ON |
85 | if (WARN_ON(!fmt->load_binary)) |
86 | return; | |
1da177e4 | 87 | write_lock(&binfmt_lock); |
74641f58 IK |
88 | insert ? list_add(&fmt->lh, &formats) : |
89 | list_add_tail(&fmt->lh, &formats); | |
1da177e4 | 90 | write_unlock(&binfmt_lock); |
1da177e4 LT |
91 | } |
92 | ||
74641f58 | 93 | EXPORT_SYMBOL(__register_binfmt); |
1da177e4 | 94 | |
f6b450d4 | 95 | void unregister_binfmt(struct linux_binfmt * fmt) |
1da177e4 | 96 | { |
1da177e4 | 97 | write_lock(&binfmt_lock); |
e4dc1b14 | 98 | list_del(&fmt->lh); |
1da177e4 | 99 | write_unlock(&binfmt_lock); |
1da177e4 LT |
100 | } |
101 | ||
102 | EXPORT_SYMBOL(unregister_binfmt); | |
103 | ||
104 | static inline void put_binfmt(struct linux_binfmt * fmt) | |
105 | { | |
106 | module_put(fmt->module); | |
107 | } | |
108 | ||
90f8572b EB |
109 | bool path_noexec(const struct path *path) |
110 | { | |
111 | return (path->mnt->mnt_flags & MNT_NOEXEC) || | |
112 | (path->mnt->mnt_sb->s_iflags & SB_I_NOEXEC); | |
113 | } | |
114 | ||
69369a70 | 115 | #ifdef CONFIG_USELIB |
1da177e4 LT |
116 | /* |
117 | * Note that a shared library must be both readable and executable due to | |
118 | * security reasons. | |
119 | * | |
120 | * Also note that we take the address to load from from the file itself. | |
121 | */ | |
1e7bfb21 | 122 | SYSCALL_DEFINE1(uselib, const char __user *, library) |
1da177e4 | 123 | { |
72c2d531 | 124 | struct linux_binfmt *fmt; |
964bd183 | 125 | struct file *file; |
91a27b2a | 126 | struct filename *tmp = getname(library); |
964bd183 | 127 | int error = PTR_ERR(tmp); |
47c805dc AV |
128 | static const struct open_flags uselib_flags = { |
129 | .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC, | |
62fb4a15 | 130 | .acc_mode = MAY_READ | MAY_EXEC, |
f9652e10 AV |
131 | .intent = LOOKUP_OPEN, |
132 | .lookup_flags = LOOKUP_FOLLOW, | |
47c805dc | 133 | }; |
964bd183 | 134 | |
6e8341a1 AV |
135 | if (IS_ERR(tmp)) |
136 | goto out; | |
137 | ||
f9652e10 | 138 | file = do_filp_open(AT_FDCWD, tmp, &uselib_flags); |
6e8341a1 AV |
139 | putname(tmp); |
140 | error = PTR_ERR(file); | |
141 | if (IS_ERR(file)) | |
1da177e4 LT |
142 | goto out; |
143 | ||
144 | error = -EINVAL; | |
496ad9aa | 145 | if (!S_ISREG(file_inode(file)->i_mode)) |
1da177e4 LT |
146 | goto exit; |
147 | ||
30524472 | 148 | error = -EACCES; |
90f8572b | 149 | if (path_noexec(&file->f_path)) |
1da177e4 LT |
150 | goto exit; |
151 | ||
2a12a9d7 | 152 | fsnotify_open(file); |
6110e3ab | 153 | |
1da177e4 | 154 | error = -ENOEXEC; |
1da177e4 | 155 | |
72c2d531 AV |
156 | read_lock(&binfmt_lock); |
157 | list_for_each_entry(fmt, &formats, lh) { | |
158 | if (!fmt->load_shlib) | |
159 | continue; | |
160 | if (!try_module_get(fmt->module)) | |
161 | continue; | |
1da177e4 | 162 | read_unlock(&binfmt_lock); |
72c2d531 AV |
163 | error = fmt->load_shlib(file); |
164 | read_lock(&binfmt_lock); | |
165 | put_binfmt(fmt); | |
166 | if (error != -ENOEXEC) | |
167 | break; | |
1da177e4 | 168 | } |
72c2d531 | 169 | read_unlock(&binfmt_lock); |
6e8341a1 | 170 | exit: |
1da177e4 LT |
171 | fput(file); |
172 | out: | |
173 | return error; | |
1da177e4 | 174 | } |
69369a70 | 175 | #endif /* #ifdef CONFIG_USELIB */ |
1da177e4 | 176 | |
b6a2fea3 | 177 | #ifdef CONFIG_MMU |
ae6b585e ON |
178 | /* |
179 | * The nascent bprm->mm is not visible until exec_mmap() but it can | |
180 | * use a lot of memory, account these pages in current->mm temporary | |
181 | * for oom_badness()->get_mm_rss(). Once exec succeeds or fails, we | |
182 | * change the counter back via acct_arg_size(0). | |
183 | */ | |
0e028465 | 184 | static void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) |
3c77f845 ON |
185 | { |
186 | struct mm_struct *mm = current->mm; | |
187 | long diff = (long)(pages - bprm->vma_pages); | |
188 | ||
189 | if (!mm || !diff) | |
190 | return; | |
191 | ||
192 | bprm->vma_pages = pages; | |
3c77f845 | 193 | add_mm_counter(mm, MM_ANONPAGES, diff); |
3c77f845 ON |
194 | } |
195 | ||
0e028465 | 196 | static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, |
b6a2fea3 OW |
197 | int write) |
198 | { | |
199 | struct page *page; | |
200 | int ret; | |
9beae1ea | 201 | unsigned int gup_flags = FOLL_FORCE; |
b6a2fea3 OW |
202 | |
203 | #ifdef CONFIG_STACK_GROWSUP | |
204 | if (write) { | |
d05f3169 | 205 | ret = expand_downwards(bprm->vma, pos); |
b6a2fea3 OW |
206 | if (ret < 0) |
207 | return NULL; | |
208 | } | |
209 | #endif | |
9beae1ea LS |
210 | |
211 | if (write) | |
212 | gup_flags |= FOLL_WRITE; | |
213 | ||
1e987790 DH |
214 | /* |
215 | * We are doing an exec(). 'current' is the process | |
216 | * doing the exec and bprm->mm is the new process's mm. | |
217 | */ | |
9beae1ea | 218 | ret = get_user_pages_remote(current, bprm->mm, pos, 1, gup_flags, |
5b56d49f | 219 | &page, NULL, NULL); |
b6a2fea3 OW |
220 | if (ret <= 0) |
221 | return NULL; | |
222 | ||
655c16a8 ON |
223 | if (write) |
224 | acct_arg_size(bprm, vma_pages(bprm->vma)); | |
b6a2fea3 OW |
225 | |
226 | return page; | |
227 | } | |
228 | ||
229 | static void put_arg_page(struct page *page) | |
230 | { | |
231 | put_page(page); | |
232 | } | |
233 | ||
b6a2fea3 OW |
234 | static void free_arg_pages(struct linux_binprm *bprm) |
235 | { | |
236 | } | |
237 | ||
238 | static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, | |
239 | struct page *page) | |
240 | { | |
241 | flush_cache_page(bprm->vma, pos, page_to_pfn(page)); | |
242 | } | |
243 | ||
244 | static int __bprm_mm_init(struct linux_binprm *bprm) | |
245 | { | |
eaccbfa5 | 246 | int err; |
b6a2fea3 OW |
247 | struct vm_area_struct *vma = NULL; |
248 | struct mm_struct *mm = bprm->mm; | |
249 | ||
490fc053 | 250 | bprm->vma = vma = vm_area_alloc(mm); |
b6a2fea3 | 251 | if (!vma) |
eaccbfa5 | 252 | return -ENOMEM; |
bfd40eaf | 253 | vma_set_anonymous(vma); |
b6a2fea3 | 254 | |
d8ed45c5 | 255 | if (mmap_write_lock_killable(mm)) { |
f268dfe9 MH |
256 | err = -EINTR; |
257 | goto err_free; | |
258 | } | |
b6a2fea3 OW |
259 | |
260 | /* | |
261 | * Place the stack at the largest stack address the architecture | |
262 | * supports. Later, we'll move this to an appropriate place. We don't | |
263 | * use STACK_TOP because that can depend on attributes which aren't | |
264 | * configured yet. | |
265 | */ | |
aacb3d17 | 266 | BUILD_BUG_ON(VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUP); |
b6a2fea3 OW |
267 | vma->vm_end = STACK_TOP_MAX; |
268 | vma->vm_start = vma->vm_end - PAGE_SIZE; | |
d9104d1c | 269 | vma->vm_flags = VM_SOFTDIRTY | VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP; |
3ed75eb8 | 270 | vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); |
462e635e | 271 | |
b6a2fea3 | 272 | err = insert_vm_struct(mm, vma); |
eaccbfa5 | 273 | if (err) |
b6a2fea3 | 274 | goto err; |
b6a2fea3 OW |
275 | |
276 | mm->stack_vm = mm->total_vm = 1; | |
d8ed45c5 | 277 | mmap_write_unlock(mm); |
b6a2fea3 | 278 | bprm->p = vma->vm_end - sizeof(void *); |
b6a2fea3 | 279 | return 0; |
b6a2fea3 | 280 | err: |
d8ed45c5 | 281 | mmap_write_unlock(mm); |
f268dfe9 | 282 | err_free: |
eaccbfa5 | 283 | bprm->vma = NULL; |
3928d4f5 | 284 | vm_area_free(vma); |
b6a2fea3 OW |
285 | return err; |
286 | } | |
287 | ||
288 | static bool valid_arg_len(struct linux_binprm *bprm, long len) | |
289 | { | |
290 | return len <= MAX_ARG_STRLEN; | |
291 | } | |
292 | ||
293 | #else | |
294 | ||
0e028465 | 295 | static inline void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) |
3c77f845 ON |
296 | { |
297 | } | |
298 | ||
0e028465 | 299 | static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, |
b6a2fea3 OW |
300 | int write) |
301 | { | |
302 | struct page *page; | |
303 | ||
304 | page = bprm->page[pos / PAGE_SIZE]; | |
305 | if (!page && write) { | |
306 | page = alloc_page(GFP_HIGHUSER|__GFP_ZERO); | |
307 | if (!page) | |
308 | return NULL; | |
309 | bprm->page[pos / PAGE_SIZE] = page; | |
310 | } | |
311 | ||
312 | return page; | |
313 | } | |
314 | ||
315 | static void put_arg_page(struct page *page) | |
316 | { | |
317 | } | |
318 | ||
319 | static void free_arg_page(struct linux_binprm *bprm, int i) | |
320 | { | |
321 | if (bprm->page[i]) { | |
322 | __free_page(bprm->page[i]); | |
323 | bprm->page[i] = NULL; | |
324 | } | |
325 | } | |
326 | ||
327 | static void free_arg_pages(struct linux_binprm *bprm) | |
328 | { | |
329 | int i; | |
330 | ||
331 | for (i = 0; i < MAX_ARG_PAGES; i++) | |
332 | free_arg_page(bprm, i); | |
333 | } | |
334 | ||
335 | static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, | |
336 | struct page *page) | |
337 | { | |
338 | } | |
339 | ||
340 | static int __bprm_mm_init(struct linux_binprm *bprm) | |
341 | { | |
342 | bprm->p = PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *); | |
343 | return 0; | |
344 | } | |
345 | ||
346 | static bool valid_arg_len(struct linux_binprm *bprm, long len) | |
347 | { | |
348 | return len <= bprm->p; | |
349 | } | |
350 | ||
351 | #endif /* CONFIG_MMU */ | |
352 | ||
353 | /* | |
354 | * Create a new mm_struct and populate it with a temporary stack | |
355 | * vm_area_struct. We don't have enough context at this point to set the stack | |
356 | * flags, permissions, and offset, so we use temporary values. We'll update | |
357 | * them later in setup_arg_pages(). | |
358 | */ | |
9cc64cea | 359 | static int bprm_mm_init(struct linux_binprm *bprm) |
b6a2fea3 OW |
360 | { |
361 | int err; | |
362 | struct mm_struct *mm = NULL; | |
363 | ||
364 | bprm->mm = mm = mm_alloc(); | |
365 | err = -ENOMEM; | |
366 | if (!mm) | |
367 | goto err; | |
368 | ||
c31dbb14 KC |
369 | /* Save current stack limit for all calculations made during exec. */ |
370 | task_lock(current->group_leader); | |
371 | bprm->rlim_stack = current->signal->rlim[RLIMIT_STACK]; | |
372 | task_unlock(current->group_leader); | |
373 | ||
b6a2fea3 OW |
374 | err = __bprm_mm_init(bprm); |
375 | if (err) | |
376 | goto err; | |
377 | ||
378 | return 0; | |
379 | ||
380 | err: | |
381 | if (mm) { | |
382 | bprm->mm = NULL; | |
383 | mmdrop(mm); | |
384 | } | |
385 | ||
386 | return err; | |
387 | } | |
388 | ||
ba2d0162 | 389 | struct user_arg_ptr { |
0e028465 ON |
390 | #ifdef CONFIG_COMPAT |
391 | bool is_compat; | |
392 | #endif | |
393 | union { | |
394 | const char __user *const __user *native; | |
395 | #ifdef CONFIG_COMPAT | |
38b983b3 | 396 | const compat_uptr_t __user *compat; |
0e028465 ON |
397 | #endif |
398 | } ptr; | |
ba2d0162 ON |
399 | }; |
400 | ||
401 | static const char __user *get_user_arg_ptr(struct user_arg_ptr argv, int nr) | |
1d1dbf81 | 402 | { |
0e028465 ON |
403 | const char __user *native; |
404 | ||
405 | #ifdef CONFIG_COMPAT | |
406 | if (unlikely(argv.is_compat)) { | |
407 | compat_uptr_t compat; | |
408 | ||
409 | if (get_user(compat, argv.ptr.compat + nr)) | |
410 | return ERR_PTR(-EFAULT); | |
1d1dbf81 | 411 | |
0e028465 ON |
412 | return compat_ptr(compat); |
413 | } | |
414 | #endif | |
415 | ||
416 | if (get_user(native, argv.ptr.native + nr)) | |
1d1dbf81 ON |
417 | return ERR_PTR(-EFAULT); |
418 | ||
0e028465 | 419 | return native; |
1d1dbf81 ON |
420 | } |
421 | ||
1da177e4 LT |
422 | /* |
423 | * count() counts the number of strings in array ARGV. | |
424 | */ | |
ba2d0162 | 425 | static int count(struct user_arg_ptr argv, int max) |
1da177e4 LT |
426 | { |
427 | int i = 0; | |
428 | ||
0e028465 | 429 | if (argv.ptr.native != NULL) { |
1da177e4 | 430 | for (;;) { |
1d1dbf81 | 431 | const char __user *p = get_user_arg_ptr(argv, i); |
1da177e4 | 432 | |
1da177e4 LT |
433 | if (!p) |
434 | break; | |
1d1dbf81 ON |
435 | |
436 | if (IS_ERR(p)) | |
437 | return -EFAULT; | |
438 | ||
6d92d4f6 | 439 | if (i >= max) |
1da177e4 | 440 | return -E2BIG; |
6d92d4f6 | 441 | ++i; |
9aea5a65 RM |
442 | |
443 | if (fatal_signal_pending(current)) | |
444 | return -ERESTARTNOHAND; | |
1da177e4 LT |
445 | cond_resched(); |
446 | } | |
447 | } | |
448 | return i; | |
449 | } | |
450 | ||
be619f7f EB |
451 | static int count_strings_kernel(const char *const *argv) |
452 | { | |
453 | int i; | |
454 | ||
455 | if (!argv) | |
456 | return 0; | |
457 | ||
458 | for (i = 0; argv[i]; ++i) { | |
459 | if (i >= MAX_ARG_STRINGS) | |
460 | return -E2BIG; | |
461 | if (fatal_signal_pending(current)) | |
462 | return -ERESTARTNOHAND; | |
463 | cond_resched(); | |
464 | } | |
465 | return i; | |
466 | } | |
467 | ||
d8b9cd54 | 468 | static int bprm_stack_limits(struct linux_binprm *bprm) |
655c16a8 ON |
469 | { |
470 | unsigned long limit, ptr_size; | |
471 | ||
655c16a8 ON |
472 | /* |
473 | * Limit to 1/4 of the max stack size or 3/4 of _STK_LIM | |
474 | * (whichever is smaller) for the argv+env strings. | |
475 | * This ensures that: | |
476 | * - the remaining binfmt code will not run out of stack space, | |
477 | * - the program will have a reasonable amount of stack left | |
478 | * to work from. | |
479 | */ | |
480 | limit = _STK_LIM / 4 * 3; | |
481 | limit = min(limit, bprm->rlim_stack.rlim_cur / 4); | |
482 | /* | |
483 | * We've historically supported up to 32 pages (ARG_MAX) | |
484 | * of argument strings even with small stacks | |
485 | */ | |
486 | limit = max_t(unsigned long, limit, ARG_MAX); | |
487 | /* | |
488 | * We must account for the size of all the argv and envp pointers to | |
489 | * the argv and envp strings, since they will also take up space in | |
490 | * the stack. They aren't stored until much later when we can't | |
491 | * signal to the parent that the child has run out of stack space. | |
492 | * Instead, calculate it here so it's possible to fail gracefully. | |
493 | */ | |
494 | ptr_size = (bprm->argc + bprm->envc) * sizeof(void *); | |
495 | if (limit <= ptr_size) | |
496 | return -E2BIG; | |
497 | limit -= ptr_size; | |
498 | ||
499 | bprm->argmin = bprm->p - limit; | |
500 | return 0; | |
501 | } | |
502 | ||
1da177e4 | 503 | /* |
b6a2fea3 OW |
504 | * 'copy_strings()' copies argument/environment strings from the old |
505 | * processes's memory to the new process's stack. The call to get_user_pages() | |
506 | * ensures the destination page is created and not swapped out. | |
1da177e4 | 507 | */ |
ba2d0162 | 508 | static int copy_strings(int argc, struct user_arg_ptr argv, |
75c96f85 | 509 | struct linux_binprm *bprm) |
1da177e4 LT |
510 | { |
511 | struct page *kmapped_page = NULL; | |
512 | char *kaddr = NULL; | |
b6a2fea3 | 513 | unsigned long kpos = 0; |
1da177e4 LT |
514 | int ret; |
515 | ||
516 | while (argc-- > 0) { | |
d7627467 | 517 | const char __user *str; |
1da177e4 LT |
518 | int len; |
519 | unsigned long pos; | |
520 | ||
1d1dbf81 ON |
521 | ret = -EFAULT; |
522 | str = get_user_arg_ptr(argv, argc); | |
523 | if (IS_ERR(str)) | |
1da177e4 | 524 | goto out; |
1da177e4 | 525 | |
1d1dbf81 ON |
526 | len = strnlen_user(str, MAX_ARG_STRLEN); |
527 | if (!len) | |
528 | goto out; | |
529 | ||
530 | ret = -E2BIG; | |
531 | if (!valid_arg_len(bprm, len)) | |
1da177e4 | 532 | goto out; |
1da177e4 | 533 | |
b6a2fea3 | 534 | /* We're going to work our way backwords. */ |
1da177e4 | 535 | pos = bprm->p; |
b6a2fea3 OW |
536 | str += len; |
537 | bprm->p -= len; | |
655c16a8 ON |
538 | #ifdef CONFIG_MMU |
539 | if (bprm->p < bprm->argmin) | |
540 | goto out; | |
541 | #endif | |
1da177e4 LT |
542 | |
543 | while (len > 0) { | |
1da177e4 | 544 | int offset, bytes_to_copy; |
1da177e4 | 545 | |
9aea5a65 RM |
546 | if (fatal_signal_pending(current)) { |
547 | ret = -ERESTARTNOHAND; | |
548 | goto out; | |
549 | } | |
7993bc1f RM |
550 | cond_resched(); |
551 | ||
1da177e4 | 552 | offset = pos % PAGE_SIZE; |
b6a2fea3 OW |
553 | if (offset == 0) |
554 | offset = PAGE_SIZE; | |
555 | ||
556 | bytes_to_copy = offset; | |
557 | if (bytes_to_copy > len) | |
558 | bytes_to_copy = len; | |
559 | ||
560 | offset -= bytes_to_copy; | |
561 | pos -= bytes_to_copy; | |
562 | str -= bytes_to_copy; | |
563 | len -= bytes_to_copy; | |
564 | ||
565 | if (!kmapped_page || kpos != (pos & PAGE_MASK)) { | |
566 | struct page *page; | |
567 | ||
568 | page = get_arg_page(bprm, pos, 1); | |
1da177e4 | 569 | if (!page) { |
b6a2fea3 | 570 | ret = -E2BIG; |
1da177e4 LT |
571 | goto out; |
572 | } | |
1da177e4 | 573 | |
b6a2fea3 OW |
574 | if (kmapped_page) { |
575 | flush_kernel_dcache_page(kmapped_page); | |
1da177e4 | 576 | kunmap(kmapped_page); |
b6a2fea3 OW |
577 | put_arg_page(kmapped_page); |
578 | } | |
1da177e4 LT |
579 | kmapped_page = page; |
580 | kaddr = kmap(kmapped_page); | |
b6a2fea3 OW |
581 | kpos = pos & PAGE_MASK; |
582 | flush_arg_page(bprm, kpos, kmapped_page); | |
1da177e4 | 583 | } |
b6a2fea3 | 584 | if (copy_from_user(kaddr+offset, str, bytes_to_copy)) { |
1da177e4 LT |
585 | ret = -EFAULT; |
586 | goto out; | |
587 | } | |
1da177e4 LT |
588 | } |
589 | } | |
590 | ret = 0; | |
591 | out: | |
b6a2fea3 OW |
592 | if (kmapped_page) { |
593 | flush_kernel_dcache_page(kmapped_page); | |
1da177e4 | 594 | kunmap(kmapped_page); |
b6a2fea3 OW |
595 | put_arg_page(kmapped_page); |
596 | } | |
1da177e4 LT |
597 | return ret; |
598 | } | |
599 | ||
600 | /* | |
986db2d1 | 601 | * Copy and argument/environment string from the kernel to the processes stack. |
1da177e4 | 602 | */ |
986db2d1 | 603 | int copy_string_kernel(const char *arg, struct linux_binprm *bprm) |
1da177e4 | 604 | { |
762a3af6 CH |
605 | int len = strnlen(arg, MAX_ARG_STRLEN) + 1 /* terminating NUL */; |
606 | unsigned long pos = bprm->p; | |
607 | ||
608 | if (len == 0) | |
609 | return -EFAULT; | |
610 | if (!valid_arg_len(bprm, len)) | |
611 | return -E2BIG; | |
612 | ||
613 | /* We're going to work our way backwards. */ | |
614 | arg += len; | |
615 | bprm->p -= len; | |
616 | if (IS_ENABLED(CONFIG_MMU) && bprm->p < bprm->argmin) | |
617 | return -E2BIG; | |
ba2d0162 | 618 | |
762a3af6 CH |
619 | while (len > 0) { |
620 | unsigned int bytes_to_copy = min_t(unsigned int, len, | |
621 | min_not_zero(offset_in_page(pos), PAGE_SIZE)); | |
622 | struct page *page; | |
623 | char *kaddr; | |
ba2d0162 | 624 | |
762a3af6 CH |
625 | pos -= bytes_to_copy; |
626 | arg -= bytes_to_copy; | |
627 | len -= bytes_to_copy; | |
ba2d0162 | 628 | |
762a3af6 CH |
629 | page = get_arg_page(bprm, pos, 1); |
630 | if (!page) | |
631 | return -E2BIG; | |
632 | kaddr = kmap_atomic(page); | |
633 | flush_arg_page(bprm, pos & PAGE_MASK, page); | |
634 | memcpy(kaddr + offset_in_page(pos), arg, bytes_to_copy); | |
635 | flush_kernel_dcache_page(page); | |
636 | kunmap_atomic(kaddr); | |
637 | put_arg_page(page); | |
638 | } | |
639 | ||
640 | return 0; | |
1da177e4 | 641 | } |
986db2d1 | 642 | EXPORT_SYMBOL(copy_string_kernel); |
1da177e4 | 643 | |
be619f7f EB |
644 | static int copy_strings_kernel(int argc, const char *const *argv, |
645 | struct linux_binprm *bprm) | |
646 | { | |
647 | while (argc-- > 0) { | |
648 | int ret = copy_string_kernel(argv[argc], bprm); | |
649 | if (ret < 0) | |
650 | return ret; | |
651 | if (fatal_signal_pending(current)) | |
652 | return -ERESTARTNOHAND; | |
653 | cond_resched(); | |
654 | } | |
655 | return 0; | |
656 | } | |
657 | ||
1da177e4 | 658 | #ifdef CONFIG_MMU |
b6a2fea3 | 659 | |
1da177e4 | 660 | /* |
b6a2fea3 OW |
661 | * During bprm_mm_init(), we create a temporary stack at STACK_TOP_MAX. Once |
662 | * the binfmt code determines where the new stack should reside, we shift it to | |
663 | * its final location. The process proceeds as follows: | |
1da177e4 | 664 | * |
b6a2fea3 OW |
665 | * 1) Use shift to calculate the new vma endpoints. |
666 | * 2) Extend vma to cover both the old and new ranges. This ensures the | |
667 | * arguments passed to subsequent functions are consistent. | |
668 | * 3) Move vma's page tables to the new range. | |
669 | * 4) Free up any cleared pgd range. | |
670 | * 5) Shrink the vma to cover only the new range. | |
1da177e4 | 671 | */ |
b6a2fea3 | 672 | static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) |
1da177e4 LT |
673 | { |
674 | struct mm_struct *mm = vma->vm_mm; | |
b6a2fea3 OW |
675 | unsigned long old_start = vma->vm_start; |
676 | unsigned long old_end = vma->vm_end; | |
677 | unsigned long length = old_end - old_start; | |
678 | unsigned long new_start = old_start - shift; | |
679 | unsigned long new_end = old_end - shift; | |
d16dfc55 | 680 | struct mmu_gather tlb; |
1da177e4 | 681 | |
b6a2fea3 | 682 | BUG_ON(new_start > new_end); |
1da177e4 | 683 | |
b6a2fea3 OW |
684 | /* |
685 | * ensure there are no vmas between where we want to go | |
686 | * and where we are | |
687 | */ | |
688 | if (vma != find_vma(mm, new_start)) | |
689 | return -EFAULT; | |
690 | ||
691 | /* | |
692 | * cover the whole range: [new_start, old_end) | |
693 | */ | |
5beb4930 RR |
694 | if (vma_adjust(vma, new_start, old_end, vma->vm_pgoff, NULL)) |
695 | return -ENOMEM; | |
b6a2fea3 OW |
696 | |
697 | /* | |
698 | * move the page tables downwards, on failure we rely on | |
699 | * process cleanup to remove whatever mess we made. | |
700 | */ | |
701 | if (length != move_page_tables(vma, old_start, | |
38a76013 | 702 | vma, new_start, length, false)) |
b6a2fea3 OW |
703 | return -ENOMEM; |
704 | ||
705 | lru_add_drain(); | |
2b047252 | 706 | tlb_gather_mmu(&tlb, mm, old_start, old_end); |
b6a2fea3 OW |
707 | if (new_end > old_start) { |
708 | /* | |
709 | * when the old and new regions overlap clear from new_end. | |
710 | */ | |
d16dfc55 | 711 | free_pgd_range(&tlb, new_end, old_end, new_end, |
6ee8630e | 712 | vma->vm_next ? vma->vm_next->vm_start : USER_PGTABLES_CEILING); |
b6a2fea3 OW |
713 | } else { |
714 | /* | |
715 | * otherwise, clean from old_start; this is done to not touch | |
716 | * the address space in [new_end, old_start) some architectures | |
717 | * have constraints on va-space that make this illegal (IA64) - | |
718 | * for the others its just a little faster. | |
719 | */ | |
d16dfc55 | 720 | free_pgd_range(&tlb, old_start, old_end, new_end, |
6ee8630e | 721 | vma->vm_next ? vma->vm_next->vm_start : USER_PGTABLES_CEILING); |
1da177e4 | 722 | } |
2b047252 | 723 | tlb_finish_mmu(&tlb, old_start, old_end); |
b6a2fea3 OW |
724 | |
725 | /* | |
5beb4930 | 726 | * Shrink the vma to just the new range. Always succeeds. |
b6a2fea3 OW |
727 | */ |
728 | vma_adjust(vma, new_start, new_end, vma->vm_pgoff, NULL); | |
729 | ||
730 | return 0; | |
1da177e4 LT |
731 | } |
732 | ||
b6a2fea3 OW |
733 | /* |
734 | * Finalizes the stack vm_area_struct. The flags and permissions are updated, | |
735 | * the stack is optionally relocated, and some extra space is added. | |
736 | */ | |
1da177e4 LT |
737 | int setup_arg_pages(struct linux_binprm *bprm, |
738 | unsigned long stack_top, | |
739 | int executable_stack) | |
740 | { | |
b6a2fea3 OW |
741 | unsigned long ret; |
742 | unsigned long stack_shift; | |
1da177e4 | 743 | struct mm_struct *mm = current->mm; |
b6a2fea3 OW |
744 | struct vm_area_struct *vma = bprm->vma; |
745 | struct vm_area_struct *prev = NULL; | |
746 | unsigned long vm_flags; | |
747 | unsigned long stack_base; | |
803bf5ec MN |
748 | unsigned long stack_size; |
749 | unsigned long stack_expand; | |
750 | unsigned long rlim_stack; | |
1da177e4 LT |
751 | |
752 | #ifdef CONFIG_STACK_GROWSUP | |
d71f290b | 753 | /* Limit stack size */ |
c31dbb14 | 754 | stack_base = bprm->rlim_stack.rlim_max; |
d71f290b JH |
755 | if (stack_base > STACK_SIZE_MAX) |
756 | stack_base = STACK_SIZE_MAX; | |
1da177e4 | 757 | |
d045c77c HD |
758 | /* Add space for stack randomization. */ |
759 | stack_base += (STACK_RND_MASK << PAGE_SHIFT); | |
760 | ||
b6a2fea3 OW |
761 | /* Make sure we didn't let the argument array grow too large. */ |
762 | if (vma->vm_end - vma->vm_start > stack_base) | |
763 | return -ENOMEM; | |
1da177e4 | 764 | |
b6a2fea3 | 765 | stack_base = PAGE_ALIGN(stack_top - stack_base); |
1da177e4 | 766 | |
b6a2fea3 OW |
767 | stack_shift = vma->vm_start - stack_base; |
768 | mm->arg_start = bprm->p - stack_shift; | |
769 | bprm->p = vma->vm_end - stack_shift; | |
1da177e4 | 770 | #else |
b6a2fea3 OW |
771 | stack_top = arch_align_stack(stack_top); |
772 | stack_top = PAGE_ALIGN(stack_top); | |
1b528181 RM |
773 | |
774 | if (unlikely(stack_top < mmap_min_addr) || | |
775 | unlikely(vma->vm_end - vma->vm_start >= stack_top - mmap_min_addr)) | |
776 | return -ENOMEM; | |
777 | ||
b6a2fea3 OW |
778 | stack_shift = vma->vm_end - stack_top; |
779 | ||
780 | bprm->p -= stack_shift; | |
1da177e4 | 781 | mm->arg_start = bprm->p; |
1da177e4 LT |
782 | #endif |
783 | ||
1da177e4 | 784 | if (bprm->loader) |
b6a2fea3 OW |
785 | bprm->loader -= stack_shift; |
786 | bprm->exec -= stack_shift; | |
1da177e4 | 787 | |
d8ed45c5 | 788 | if (mmap_write_lock_killable(mm)) |
f268dfe9 MH |
789 | return -EINTR; |
790 | ||
96a8e13e | 791 | vm_flags = VM_STACK_FLAGS; |
b6a2fea3 OW |
792 | |
793 | /* | |
794 | * Adjust stack execute permissions; explicitly enable for | |
795 | * EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X and leave alone | |
796 | * (arch default) otherwise. | |
797 | */ | |
798 | if (unlikely(executable_stack == EXSTACK_ENABLE_X)) | |
799 | vm_flags |= VM_EXEC; | |
800 | else if (executable_stack == EXSTACK_DISABLE_X) | |
801 | vm_flags &= ~VM_EXEC; | |
802 | vm_flags |= mm->def_flags; | |
a8bef8ff | 803 | vm_flags |= VM_STACK_INCOMPLETE_SETUP; |
b6a2fea3 OW |
804 | |
805 | ret = mprotect_fixup(vma, &prev, vma->vm_start, vma->vm_end, | |
806 | vm_flags); | |
807 | if (ret) | |
808 | goto out_unlock; | |
809 | BUG_ON(prev != vma); | |
810 | ||
47a2ebb7 AD |
811 | if (unlikely(vm_flags & VM_EXEC)) { |
812 | pr_warn_once("process '%pD4' started with executable stack\n", | |
813 | bprm->file); | |
814 | } | |
815 | ||
b6a2fea3 OW |
816 | /* Move stack pages down in memory. */ |
817 | if (stack_shift) { | |
818 | ret = shift_arg_pages(vma, stack_shift); | |
fc63cf23 AB |
819 | if (ret) |
820 | goto out_unlock; | |
1da177e4 LT |
821 | } |
822 | ||
a8bef8ff MG |
823 | /* mprotect_fixup is overkill to remove the temporary stack flags */ |
824 | vma->vm_flags &= ~VM_STACK_INCOMPLETE_SETUP; | |
825 | ||
5ef097dd | 826 | stack_expand = 131072UL; /* randomly 32*4k (or 2*64k) pages */ |
803bf5ec MN |
827 | stack_size = vma->vm_end - vma->vm_start; |
828 | /* | |
829 | * Align this down to a page boundary as expand_stack | |
830 | * will align it up. | |
831 | */ | |
c31dbb14 | 832 | rlim_stack = bprm->rlim_stack.rlim_cur & PAGE_MASK; |
b6a2fea3 | 833 | #ifdef CONFIG_STACK_GROWSUP |
803bf5ec MN |
834 | if (stack_size + stack_expand > rlim_stack) |
835 | stack_base = vma->vm_start + rlim_stack; | |
836 | else | |
837 | stack_base = vma->vm_end + stack_expand; | |
b6a2fea3 | 838 | #else |
803bf5ec MN |
839 | if (stack_size + stack_expand > rlim_stack) |
840 | stack_base = vma->vm_end - rlim_stack; | |
841 | else | |
842 | stack_base = vma->vm_start - stack_expand; | |
b6a2fea3 | 843 | #endif |
3af9e859 | 844 | current->mm->start_stack = bprm->p; |
b6a2fea3 OW |
845 | ret = expand_stack(vma, stack_base); |
846 | if (ret) | |
847 | ret = -EFAULT; | |
848 | ||
849 | out_unlock: | |
d8ed45c5 | 850 | mmap_write_unlock(mm); |
fc63cf23 | 851 | return ret; |
1da177e4 | 852 | } |
1da177e4 LT |
853 | EXPORT_SYMBOL(setup_arg_pages); |
854 | ||
7e7ec6a9 NP |
855 | #else |
856 | ||
857 | /* | |
858 | * Transfer the program arguments and environment from the holding pages | |
859 | * onto the stack. The provided stack pointer is adjusted accordingly. | |
860 | */ | |
861 | int transfer_args_to_stack(struct linux_binprm *bprm, | |
862 | unsigned long *sp_location) | |
863 | { | |
864 | unsigned long index, stop, sp; | |
865 | int ret = 0; | |
866 | ||
867 | stop = bprm->p >> PAGE_SHIFT; | |
868 | sp = *sp_location; | |
869 | ||
870 | for (index = MAX_ARG_PAGES - 1; index >= stop; index--) { | |
871 | unsigned int offset = index == stop ? bprm->p & ~PAGE_MASK : 0; | |
872 | char *src = kmap(bprm->page[index]) + offset; | |
873 | sp -= PAGE_SIZE - offset; | |
874 | if (copy_to_user((void *) sp, src, PAGE_SIZE - offset) != 0) | |
875 | ret = -EFAULT; | |
876 | kunmap(bprm->page[index]); | |
877 | if (ret) | |
878 | goto out; | |
879 | } | |
880 | ||
881 | *sp_location = sp; | |
882 | ||
883 | out: | |
884 | return ret; | |
885 | } | |
886 | EXPORT_SYMBOL(transfer_args_to_stack); | |
887 | ||
1da177e4 LT |
888 | #endif /* CONFIG_MMU */ |
889 | ||
51f39a1f | 890 | static struct file *do_open_execat(int fd, struct filename *name, int flags) |
1da177e4 | 891 | { |
1da177e4 | 892 | struct file *file; |
e56b6a5d | 893 | int err; |
51f39a1f | 894 | struct open_flags open_exec_flags = { |
47c805dc | 895 | .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC, |
62fb4a15 | 896 | .acc_mode = MAY_EXEC, |
f9652e10 AV |
897 | .intent = LOOKUP_OPEN, |
898 | .lookup_flags = LOOKUP_FOLLOW, | |
47c805dc | 899 | }; |
1da177e4 | 900 | |
51f39a1f DD |
901 | if ((flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0) |
902 | return ERR_PTR(-EINVAL); | |
903 | if (flags & AT_SYMLINK_NOFOLLOW) | |
904 | open_exec_flags.lookup_flags &= ~LOOKUP_FOLLOW; | |
905 | if (flags & AT_EMPTY_PATH) | |
906 | open_exec_flags.lookup_flags |= LOOKUP_EMPTY; | |
907 | ||
908 | file = do_filp_open(fd, name, &open_exec_flags); | |
6e8341a1 | 909 | if (IS_ERR(file)) |
e56b6a5d CH |
910 | goto out; |
911 | ||
912 | err = -EACCES; | |
496ad9aa | 913 | if (!S_ISREG(file_inode(file)->i_mode)) |
6e8341a1 | 914 | goto exit; |
e56b6a5d | 915 | |
90f8572b | 916 | if (path_noexec(&file->f_path)) |
6e8341a1 | 917 | goto exit; |
e56b6a5d CH |
918 | |
919 | err = deny_write_access(file); | |
6e8341a1 AV |
920 | if (err) |
921 | goto exit; | |
1da177e4 | 922 | |
51f39a1f DD |
923 | if (name->name[0] != '\0') |
924 | fsnotify_open(file); | |
925 | ||
6e8341a1 | 926 | out: |
e56b6a5d CH |
927 | return file; |
928 | ||
6e8341a1 AV |
929 | exit: |
930 | fput(file); | |
e56b6a5d CH |
931 | return ERR_PTR(err); |
932 | } | |
c4ad8f98 LT |
933 | |
934 | struct file *open_exec(const char *name) | |
935 | { | |
51689104 PM |
936 | struct filename *filename = getname_kernel(name); |
937 | struct file *f = ERR_CAST(filename); | |
938 | ||
939 | if (!IS_ERR(filename)) { | |
940 | f = do_open_execat(AT_FDCWD, filename, 0); | |
941 | putname(filename); | |
942 | } | |
943 | return f; | |
c4ad8f98 | 944 | } |
1da177e4 LT |
945 | EXPORT_SYMBOL(open_exec); |
946 | ||
b44a7dfc | 947 | int kernel_read_file(struct file *file, void **buf, loff_t *size, |
bc8ca5b9 | 948 | loff_t max_size, enum kernel_read_file_id id) |
b44a7dfc MZ |
949 | { |
950 | loff_t i_size, pos; | |
951 | ssize_t bytes = 0; | |
952 | int ret; | |
953 | ||
954 | if (!S_ISREG(file_inode(file)->i_mode) || max_size < 0) | |
955 | return -EINVAL; | |
956 | ||
7bd698b3 | 957 | ret = deny_write_access(file); |
39eeb4fb MZ |
958 | if (ret) |
959 | return ret; | |
960 | ||
7bd698b3 | 961 | ret = security_kernel_read_file(file, id); |
39d637af | 962 | if (ret) |
7bd698b3 | 963 | goto out; |
39d637af | 964 | |
b44a7dfc | 965 | i_size = i_size_read(file_inode(file)); |
39d637af DK |
966 | if (i_size <= 0) { |
967 | ret = -EINVAL; | |
968 | goto out; | |
969 | } | |
691115c3 EB |
970 | if (i_size > SIZE_MAX || (max_size > 0 && i_size > max_size)) { |
971 | ret = -EFBIG; | |
972 | goto out; | |
973 | } | |
b44a7dfc | 974 | |
a098ecd2 SB |
975 | if (id != READING_FIRMWARE_PREALLOC_BUFFER) |
976 | *buf = vmalloc(i_size); | |
39d637af DK |
977 | if (!*buf) { |
978 | ret = -ENOMEM; | |
979 | goto out; | |
980 | } | |
b44a7dfc MZ |
981 | |
982 | pos = 0; | |
983 | while (pos < i_size) { | |
bdd1d2d3 | 984 | bytes = kernel_read(file, *buf + pos, i_size - pos, &pos); |
b44a7dfc MZ |
985 | if (bytes < 0) { |
986 | ret = bytes; | |
f612acfa | 987 | goto out_free; |
b44a7dfc MZ |
988 | } |
989 | ||
990 | if (bytes == 0) | |
991 | break; | |
b44a7dfc MZ |
992 | } |
993 | ||
994 | if (pos != i_size) { | |
995 | ret = -EIO; | |
39d637af | 996 | goto out_free; |
b44a7dfc MZ |
997 | } |
998 | ||
bc8ca5b9 | 999 | ret = security_kernel_post_read_file(file, *buf, i_size, id); |
b44a7dfc MZ |
1000 | if (!ret) |
1001 | *size = pos; | |
1002 | ||
39d637af | 1003 | out_free: |
b44a7dfc | 1004 | if (ret < 0) { |
a098ecd2 SB |
1005 | if (id != READING_FIRMWARE_PREALLOC_BUFFER) { |
1006 | vfree(*buf); | |
1007 | *buf = NULL; | |
1008 | } | |
b44a7dfc | 1009 | } |
39d637af DK |
1010 | |
1011 | out: | |
1012 | allow_write_access(file); | |
b44a7dfc MZ |
1013 | return ret; |
1014 | } | |
1015 | EXPORT_SYMBOL_GPL(kernel_read_file); | |
1016 | ||
711aab1d | 1017 | int kernel_read_file_from_path(const char *path, void **buf, loff_t *size, |
09596b94 MZ |
1018 | loff_t max_size, enum kernel_read_file_id id) |
1019 | { | |
1020 | struct file *file; | |
1021 | int ret; | |
1022 | ||
1023 | if (!path || !*path) | |
1024 | return -EINVAL; | |
1025 | ||
1026 | file = filp_open(path, O_RDONLY, 0); | |
1027 | if (IS_ERR(file)) | |
1028 | return PTR_ERR(file); | |
1029 | ||
1030 | ret = kernel_read_file(file, buf, size, max_size, id); | |
1031 | fput(file); | |
1032 | return ret; | |
1033 | } | |
1034 | EXPORT_SYMBOL_GPL(kernel_read_file_from_path); | |
1035 | ||
901cff7c TM |
1036 | int kernel_read_file_from_path_initns(const char *path, void **buf, |
1037 | loff_t *size, loff_t max_size, | |
1038 | enum kernel_read_file_id id) | |
1039 | { | |
1040 | struct file *file; | |
1041 | struct path root; | |
1042 | int ret; | |
1043 | ||
1044 | if (!path || !*path) | |
1045 | return -EINVAL; | |
1046 | ||
1047 | task_lock(&init_task); | |
1048 | get_fs_root(init_task.fs, &root); | |
1049 | task_unlock(&init_task); | |
1050 | ||
1051 | file = file_open_root(root.dentry, root.mnt, path, O_RDONLY, 0); | |
1052 | path_put(&root); | |
1053 | if (IS_ERR(file)) | |
1054 | return PTR_ERR(file); | |
1055 | ||
1056 | ret = kernel_read_file(file, buf, size, max_size, id); | |
1057 | fput(file); | |
1058 | return ret; | |
1059 | } | |
1060 | EXPORT_SYMBOL_GPL(kernel_read_file_from_path_initns); | |
1061 | ||
b844f0ec MZ |
1062 | int kernel_read_file_from_fd(int fd, void **buf, loff_t *size, loff_t max_size, |
1063 | enum kernel_read_file_id id) | |
1064 | { | |
1065 | struct fd f = fdget(fd); | |
1066 | int ret = -EBADF; | |
1067 | ||
1068 | if (!f.file) | |
1069 | goto out; | |
1070 | ||
1071 | ret = kernel_read_file(f.file, buf, size, max_size, id); | |
1072 | out: | |
1073 | fdput(f); | |
1074 | return ret; | |
1075 | } | |
1076 | EXPORT_SYMBOL_GPL(kernel_read_file_from_fd); | |
1077 | ||
48304f79 CH |
1078 | #if defined(CONFIG_HAVE_AOUT) || defined(CONFIG_BINFMT_FLAT) || \ |
1079 | defined(CONFIG_BINFMT_ELF_FDPIC) | |
3dc20cb2 AV |
1080 | ssize_t read_code(struct file *file, unsigned long addr, loff_t pos, size_t len) |
1081 | { | |
ec695579 | 1082 | ssize_t res = vfs_read(file, (void __user *)addr, len, &pos); |
3dc20cb2 | 1083 | if (res > 0) |
bce2b68b | 1084 | flush_icache_user_range(addr, addr + len); |
3dc20cb2 AV |
1085 | return res; |
1086 | } | |
1087 | EXPORT_SYMBOL(read_code); | |
48304f79 | 1088 | #endif |
3dc20cb2 | 1089 | |
eea96732 EB |
1090 | /* |
1091 | * Maps the mm_struct mm into the current task struct. | |
1092 | * On success, this function returns with the mutex | |
1093 | * exec_update_mutex locked. | |
1094 | */ | |
1da177e4 LT |
1095 | static int exec_mmap(struct mm_struct *mm) |
1096 | { | |
1097 | struct task_struct *tsk; | |
615d6e87 | 1098 | struct mm_struct *old_mm, *active_mm; |
eea96732 | 1099 | int ret; |
1da177e4 LT |
1100 | |
1101 | /* Notify parent that we're no longer interested in the old VM */ | |
1102 | tsk = current; | |
1103 | old_mm = current->mm; | |
4610ba7a | 1104 | exec_mm_release(tsk, old_mm); |
a28bf136 EB |
1105 | if (old_mm) |
1106 | sync_mm_rss(old_mm); | |
1da177e4 | 1107 | |
eea96732 EB |
1108 | ret = mutex_lock_killable(&tsk->signal->exec_update_mutex); |
1109 | if (ret) | |
1110 | return ret; | |
1111 | ||
1da177e4 LT |
1112 | if (old_mm) { |
1113 | /* | |
1114 | * Make sure that if there is a core dump in progress | |
1115 | * for the old mm, we get out and die instead of going | |
c1e8d7c6 | 1116 | * through with the exec. We must hold mmap_lock around |
999d9fc1 | 1117 | * checking core_state and changing tsk->mm. |
1da177e4 | 1118 | */ |
d8ed45c5 | 1119 | mmap_read_lock(old_mm); |
999d9fc1 | 1120 | if (unlikely(old_mm->core_state)) { |
d8ed45c5 | 1121 | mmap_read_unlock(old_mm); |
eea96732 | 1122 | mutex_unlock(&tsk->signal->exec_update_mutex); |
1da177e4 LT |
1123 | return -EINTR; |
1124 | } | |
1125 | } | |
eea96732 | 1126 | |
1da177e4 LT |
1127 | task_lock(tsk); |
1128 | active_mm = tsk->active_mm; | |
227a4aad | 1129 | membarrier_exec_mmap(mm); |
1da177e4 LT |
1130 | tsk->mm = mm; |
1131 | tsk->active_mm = mm; | |
1132 | activate_mm(active_mm, mm); | |
615d6e87 DB |
1133 | tsk->mm->vmacache_seqnum = 0; |
1134 | vmacache_flush(tsk); | |
1da177e4 | 1135 | task_unlock(tsk); |
1da177e4 | 1136 | if (old_mm) { |
d8ed45c5 | 1137 | mmap_read_unlock(old_mm); |
7dddb12c | 1138 | BUG_ON(active_mm != old_mm); |
701085b2 | 1139 | setmax_mm_hiwater_rss(&tsk->signal->maxrss, old_mm); |
31a78f23 | 1140 | mm_update_next_owner(old_mm); |
1da177e4 LT |
1141 | mmput(old_mm); |
1142 | return 0; | |
1143 | } | |
1144 | mmdrop(active_mm); | |
1145 | return 0; | |
1146 | } | |
1147 | ||
858119e1 | 1148 | static int de_thread(struct task_struct *tsk) |
1da177e4 LT |
1149 | { |
1150 | struct signal_struct *sig = tsk->signal; | |
b2c903b8 | 1151 | struct sighand_struct *oldsighand = tsk->sighand; |
1da177e4 | 1152 | spinlock_t *lock = &oldsighand->siglock; |
1da177e4 | 1153 | |
aafe6c2a | 1154 | if (thread_group_empty(tsk)) |
1da177e4 LT |
1155 | goto no_thread_group; |
1156 | ||
1157 | /* | |
1158 | * Kill all other threads in the thread group. | |
1da177e4 | 1159 | */ |
1da177e4 | 1160 | spin_lock_irq(lock); |
ed5d2cac | 1161 | if (signal_group_exit(sig)) { |
1da177e4 LT |
1162 | /* |
1163 | * Another group action in progress, just | |
1164 | * return so that the signal is processed. | |
1165 | */ | |
1166 | spin_unlock_irq(lock); | |
1da177e4 LT |
1167 | return -EAGAIN; |
1168 | } | |
d344193a | 1169 | |
ed5d2cac | 1170 | sig->group_exit_task = tsk; |
d344193a ON |
1171 | sig->notify_count = zap_other_threads(tsk); |
1172 | if (!thread_group_leader(tsk)) | |
1173 | sig->notify_count--; | |
1da177e4 | 1174 | |
d344193a | 1175 | while (sig->notify_count) { |
d5bbd43d | 1176 | __set_current_state(TASK_KILLABLE); |
1da177e4 | 1177 | spin_unlock_irq(lock); |
a72173ec | 1178 | schedule(); |
08d405c8 | 1179 | if (__fatal_signal_pending(tsk)) |
d5bbd43d | 1180 | goto killed; |
1da177e4 LT |
1181 | spin_lock_irq(lock); |
1182 | } | |
1da177e4 LT |
1183 | spin_unlock_irq(lock); |
1184 | ||
1185 | /* | |
1186 | * At this point all other threads have exited, all we have to | |
1187 | * do is to wait for the thread group leader to become inactive, | |
1188 | * and to assume its PID: | |
1189 | */ | |
aafe6c2a | 1190 | if (!thread_group_leader(tsk)) { |
8187926b | 1191 | struct task_struct *leader = tsk->group_leader; |
6db840fa | 1192 | |
6db840fa | 1193 | for (;;) { |
780de9dd | 1194 | cgroup_threadgroup_change_begin(tsk); |
6db840fa | 1195 | write_lock_irq(&tasklist_lock); |
dfcce791 KT |
1196 | /* |
1197 | * Do this under tasklist_lock to ensure that | |
1198 | * exit_notify() can't miss ->group_exit_task | |
1199 | */ | |
1200 | sig->notify_count = -1; | |
6db840fa ON |
1201 | if (likely(leader->exit_state)) |
1202 | break; | |
d5bbd43d | 1203 | __set_current_state(TASK_KILLABLE); |
6db840fa | 1204 | write_unlock_irq(&tasklist_lock); |
780de9dd | 1205 | cgroup_threadgroup_change_end(tsk); |
a72173ec | 1206 | schedule(); |
08d405c8 | 1207 | if (__fatal_signal_pending(tsk)) |
d5bbd43d | 1208 | goto killed; |
6db840fa | 1209 | } |
1da177e4 | 1210 | |
f5e90281 RM |
1211 | /* |
1212 | * The only record we have of the real-time age of a | |
1213 | * process, regardless of execs it's done, is start_time. | |
1214 | * All the past CPU time is accumulated in signal_struct | |
1215 | * from sister threads now dead. But in this non-leader | |
1216 | * exec, nothing survives from the original leader thread, | |
1217 | * whose birth marks the true age of this process now. | |
1218 | * When we take on its identity by switching to its PID, we | |
1219 | * also take its birthdate (always earlier than our own). | |
1220 | */ | |
aafe6c2a | 1221 | tsk->start_time = leader->start_time; |
cf25e24d | 1222 | tsk->start_boottime = leader->start_boottime; |
f5e90281 | 1223 | |
bac0abd6 | 1224 | BUG_ON(!same_thread_group(leader, tsk)); |
1da177e4 LT |
1225 | /* |
1226 | * An exec() starts a new thread group with the | |
1227 | * TGID of the previous thread group. Rehash the | |
1228 | * two threads with a switched PID, and release | |
1229 | * the former thread group leader: | |
1230 | */ | |
d73d6529 EB |
1231 | |
1232 | /* Become a process group leader with the old leader's pid. | |
c18258c6 | 1233 | * The old leader becomes a thread of the this thread group. |
d73d6529 | 1234 | */ |
6b03d130 | 1235 | exchange_tids(tsk, leader); |
6883f81a | 1236 | transfer_pid(leader, tsk, PIDTYPE_TGID); |
aafe6c2a EB |
1237 | transfer_pid(leader, tsk, PIDTYPE_PGID); |
1238 | transfer_pid(leader, tsk, PIDTYPE_SID); | |
9cd80bbb | 1239 | |
aafe6c2a | 1240 | list_replace_rcu(&leader->tasks, &tsk->tasks); |
9cd80bbb | 1241 | list_replace_init(&leader->sibling, &tsk->sibling); |
1da177e4 | 1242 | |
aafe6c2a EB |
1243 | tsk->group_leader = tsk; |
1244 | leader->group_leader = tsk; | |
de12a787 | 1245 | |
aafe6c2a | 1246 | tsk->exit_signal = SIGCHLD; |
087806b1 | 1247 | leader->exit_signal = -1; |
962b564c ON |
1248 | |
1249 | BUG_ON(leader->exit_state != EXIT_ZOMBIE); | |
1250 | leader->exit_state = EXIT_DEAD; | |
eac1b5e5 ON |
1251 | |
1252 | /* | |
1253 | * We are going to release_task()->ptrace_unlink() silently, | |
1254 | * the tracer can sleep in do_wait(). EXIT_DEAD guarantees | |
1255 | * the tracer wont't block again waiting for this thread. | |
1256 | */ | |
1257 | if (unlikely(leader->ptrace)) | |
1258 | __wake_up_parent(leader, leader->parent); | |
1da177e4 | 1259 | write_unlock_irq(&tasklist_lock); |
780de9dd | 1260 | cgroup_threadgroup_change_end(tsk); |
8187926b ON |
1261 | |
1262 | release_task(leader); | |
ed5d2cac | 1263 | } |
1da177e4 | 1264 | |
6db840fa ON |
1265 | sig->group_exit_task = NULL; |
1266 | sig->notify_count = 0; | |
1da177e4 LT |
1267 | |
1268 | no_thread_group: | |
e6368253 ON |
1269 | /* we have changed execution domain */ |
1270 | tsk->exit_signal = SIGCHLD; | |
1271 | ||
02169155 EB |
1272 | BUG_ON(!thread_group_leader(tsk)); |
1273 | return 0; | |
1274 | ||
1275 | killed: | |
1276 | /* protects against exit_notify() and __exit_signal() */ | |
1277 | read_lock(&tasklist_lock); | |
1278 | sig->group_exit_task = NULL; | |
1279 | sig->notify_count = 0; | |
1280 | read_unlock(&tasklist_lock); | |
1281 | return -EAGAIN; | |
1282 | } | |
1283 | ||
1284 | ||
7a60ef48 EB |
1285 | /* |
1286 | * This function makes sure the current process has its own signal table, | |
1287 | * so that flush_signal_handlers can later reset the handlers without | |
1288 | * disturbing other processes. (Other processes might share the signal | |
1289 | * table via the CLONE_SIGHAND option to clone().) | |
1290 | */ | |
02169155 EB |
1291 | static int unshare_sighand(struct task_struct *me) |
1292 | { | |
1293 | struct sighand_struct *oldsighand = me->sighand; | |
329f7dba | 1294 | |
d036bda7 | 1295 | if (refcount_read(&oldsighand->count) != 1) { |
b2c903b8 | 1296 | struct sighand_struct *newsighand; |
1da177e4 | 1297 | /* |
b2c903b8 ON |
1298 | * This ->sighand is shared with the CLONE_SIGHAND |
1299 | * but not CLONE_THREAD task, switch to the new one. | |
1da177e4 | 1300 | */ |
b2c903b8 ON |
1301 | newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL); |
1302 | if (!newsighand) | |
1303 | return -ENOMEM; | |
1304 | ||
d036bda7 | 1305 | refcount_set(&newsighand->count, 1); |
1da177e4 LT |
1306 | memcpy(newsighand->action, oldsighand->action, |
1307 | sizeof(newsighand->action)); | |
1308 | ||
1309 | write_lock_irq(&tasklist_lock); | |
1310 | spin_lock(&oldsighand->siglock); | |
02169155 | 1311 | rcu_assign_pointer(me->sighand, newsighand); |
1da177e4 LT |
1312 | spin_unlock(&oldsighand->siglock); |
1313 | write_unlock_irq(&tasklist_lock); | |
1314 | ||
fba2afaa | 1315 | __cleanup_sighand(oldsighand); |
1da177e4 | 1316 | } |
1da177e4 LT |
1317 | return 0; |
1318 | } | |
0840a90d | 1319 | |
3756f640 | 1320 | char *__get_task_comm(char *buf, size_t buf_size, struct task_struct *tsk) |
1da177e4 | 1321 | { |
1da177e4 | 1322 | task_lock(tsk); |
3756f640 | 1323 | strncpy(buf, tsk->comm, buf_size); |
1da177e4 | 1324 | task_unlock(tsk); |
59714d65 | 1325 | return buf; |
1da177e4 | 1326 | } |
3756f640 | 1327 | EXPORT_SYMBOL_GPL(__get_task_comm); |
1da177e4 | 1328 | |
6a6d27de AV |
1329 | /* |
1330 | * These functions flushes out all traces of the currently running executable | |
1331 | * so that a new one can be started | |
1332 | */ | |
1333 | ||
82b89778 | 1334 | void __set_task_comm(struct task_struct *tsk, const char *buf, bool exec) |
1da177e4 LT |
1335 | { |
1336 | task_lock(tsk); | |
43d2b113 | 1337 | trace_task_rename(tsk, buf); |
1da177e4 LT |
1338 | strlcpy(tsk->comm, buf, sizeof(tsk->comm)); |
1339 | task_unlock(tsk); | |
82b89778 | 1340 | perf_event_comm(tsk, exec); |
1da177e4 LT |
1341 | } |
1342 | ||
a9208e42 KC |
1343 | /* |
1344 | * Calling this is the point of no return. None of the failures will be | |
1345 | * seen by userspace since either the process is already taking a fatal | |
1346 | * signal (via de_thread() or coredump), or will have SEGV raised | |
13c432b5 | 1347 | * (after exec_mmap()) by search_binary_handler (see below). |
a9208e42 | 1348 | */ |
2388777a | 1349 | int begin_new_exec(struct linux_binprm * bprm) |
1da177e4 | 1350 | { |
2ca7be7d | 1351 | struct task_struct *me = current; |
221af7f8 | 1352 | int retval; |
1da177e4 | 1353 | |
56305aa9 EB |
1354 | /* Once we are committed compute the creds */ |
1355 | retval = bprm_creds_from_file(bprm); | |
1356 | if (retval) | |
1357 | return retval; | |
1358 | ||
6834e0bb EB |
1359 | /* |
1360 | * Ensure all future errors are fatal. | |
1361 | */ | |
1362 | bprm->point_of_no_return = true; | |
1363 | ||
1da177e4 | 1364 | /* |
02169155 | 1365 | * Make this the only thread in the thread group. |
1da177e4 | 1366 | */ |
2ca7be7d | 1367 | retval = de_thread(me); |
1da177e4 LT |
1368 | if (retval) |
1369 | goto out; | |
1370 | ||
6e399cd1 DB |
1371 | /* |
1372 | * Must be called _before_ exec_mmap() as bprm->mm is | |
1373 | * not visibile until then. This also enables the update | |
1374 | * to be lockless. | |
1375 | */ | |
925d1c40 | 1376 | set_mm_exe_file(bprm->mm, bprm->file); |
6e399cd1 | 1377 | |
b8a61c9e | 1378 | /* If the binary is not readable then enforce mm->dumpable=0 */ |
f87d1c95 | 1379 | would_dump(bprm, bprm->file); |
b8a61c9e EB |
1380 | if (bprm->have_execfd) |
1381 | would_dump(bprm, bprm->executable); | |
f87d1c95 | 1382 | |
1da177e4 LT |
1383 | /* |
1384 | * Release all of the old mmap stuff | |
1385 | */ | |
3c77f845 | 1386 | acct_arg_size(bprm, 0); |
1da177e4 LT |
1387 | retval = exec_mmap(bprm->mm); |
1388 | if (retval) | |
fd8328be | 1389 | goto out; |
1da177e4 | 1390 | |
a9208e42 | 1391 | bprm->mm = NULL; |
7ab02af4 | 1392 | |
ccf0fa6b EB |
1393 | #ifdef CONFIG_POSIX_TIMERS |
1394 | exit_itimers(me->signal); | |
1395 | flush_itimer_signals(); | |
1396 | #endif | |
1397 | ||
1398 | /* | |
1399 | * Make the signal table private. | |
1400 | */ | |
1401 | retval = unshare_sighand(me); | |
1402 | if (retval) | |
89826cce | 1403 | goto out_unlock; |
ccf0fa6b | 1404 | |
dac853ae | 1405 | set_fs(USER_DS); |
2ca7be7d | 1406 | me->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD | |
b88fae64 | 1407 | PF_NOFREEZE | PF_NO_SETAFFINITY); |
7ab02af4 | 1408 | flush_thread(); |
2ca7be7d | 1409 | me->personality &= ~bprm->per_clear; |
7ab02af4 | 1410 | |
613cc2b6 AS |
1411 | /* |
1412 | * We have to apply CLOEXEC before we change whether the process is | |
1413 | * dumpable (in setup_new_exec) to avoid a race with a process in userspace | |
1414 | * trying to access the should-be-closed file descriptors of a process | |
1415 | * undergoing exec(2). | |
1416 | */ | |
2ca7be7d | 1417 | do_close_on_exec(me->files); |
f84df2a6 | 1418 | |
64701dee | 1419 | if (bprm->secureexec) { |
fe8993b3 | 1420 | /* Make sure parent cannot signal privileged process. */ |
7d503feb | 1421 | me->pdeath_signal = 0; |
fe8993b3 | 1422 | |
64701dee KC |
1423 | /* |
1424 | * For secureexec, reset the stack limit to sane default to | |
1425 | * avoid bad behavior from the prior rlimits. This has to | |
1426 | * happen before arch_pick_mmap_layout(), which examines | |
1427 | * RLIMIT_STACK, but after the point of no return to avoid | |
779f4e1c | 1428 | * needing to clean up the change on failure. |
64701dee | 1429 | */ |
c31dbb14 KC |
1430 | if (bprm->rlim_stack.rlim_cur > _STK_LIM) |
1431 | bprm->rlim_stack.rlim_cur = _STK_LIM; | |
64701dee KC |
1432 | } |
1433 | ||
7d503feb | 1434 | me->sas_ss_sp = me->sas_ss_size = 0; |
1da177e4 | 1435 | |
e816c201 KC |
1436 | /* |
1437 | * Figure out dumpability. Note that this checking only of current | |
1438 | * is wrong, but userspace depends on it. This should be testing | |
1439 | * bprm->secureexec instead. | |
1440 | */ | |
473d8963 | 1441 | if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP || |
e816c201 KC |
1442 | !(uid_eq(current_euid(), current_uid()) && |
1443 | gid_eq(current_egid(), current_gid()))) | |
6c5d5238 | 1444 | set_dumpable(current->mm, suid_dumpable); |
473d8963 KC |
1445 | else |
1446 | set_dumpable(current->mm, SUID_DUMP_USER); | |
d6e71144 | 1447 | |
e041e328 | 1448 | perf_event_exec(); |
7d503feb | 1449 | __set_task_comm(me, kbasename(bprm->filename), true); |
1da177e4 | 1450 | |
1da177e4 LT |
1451 | /* An exec changes our domain. We are no longer part of the thread |
1452 | group */ | |
7d503feb EB |
1453 | WRITE_ONCE(me->self_exec_id, me->self_exec_id + 1); |
1454 | flush_signal_handlers(me, 0); | |
96ecee29 EB |
1455 | |
1456 | /* | |
1457 | * install the new credentials for this executable | |
1458 | */ | |
1459 | security_bprm_committing_creds(bprm); | |
1460 | ||
1461 | commit_creds(bprm->cred); | |
1462 | bprm->cred = NULL; | |
1463 | ||
1464 | /* | |
1465 | * Disable monitoring for regular users | |
1466 | * when executing setuid binaries. Must | |
1467 | * wait until new credentials are committed | |
1468 | * by commit_creds() above | |
1469 | */ | |
7d503feb EB |
1470 | if (get_dumpable(me->mm) != SUID_DUMP_USER) |
1471 | perf_event_exit_task(me); | |
96ecee29 EB |
1472 | /* |
1473 | * cred_guard_mutex must be held at least to this point to prevent | |
1474 | * ptrace_attach() from altering our determination of the task's | |
1475 | * credentials; any time after this it may be unlocked. | |
1476 | */ | |
1477 | security_bprm_committed_creds(bprm); | |
b8a61c9e EB |
1478 | |
1479 | /* Pass the opened binary to the interpreter. */ | |
1480 | if (bprm->have_execfd) { | |
1481 | retval = get_unused_fd_flags(0); | |
1482 | if (retval < 0) | |
1483 | goto out_unlock; | |
1484 | fd_install(retval, bprm->executable); | |
1485 | bprm->executable = NULL; | |
1486 | bprm->execfd = retval; | |
1487 | } | |
221af7f8 LT |
1488 | return 0; |
1489 | ||
df9e4d2c EB |
1490 | out_unlock: |
1491 | mutex_unlock(&me->signal->exec_update_mutex); | |
221af7f8 LT |
1492 | out: |
1493 | return retval; | |
1494 | } | |
2388777a | 1495 | EXPORT_SYMBOL(begin_new_exec); |
221af7f8 | 1496 | |
1b5d783c AV |
1497 | void would_dump(struct linux_binprm *bprm, struct file *file) |
1498 | { | |
f84df2a6 EB |
1499 | struct inode *inode = file_inode(file); |
1500 | if (inode_permission(inode, MAY_READ) < 0) { | |
1501 | struct user_namespace *old, *user_ns; | |
1b5d783c | 1502 | bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; |
f84df2a6 EB |
1503 | |
1504 | /* Ensure mm->user_ns contains the executable */ | |
1505 | user_ns = old = bprm->mm->user_ns; | |
1506 | while ((user_ns != &init_user_ns) && | |
1507 | !privileged_wrt_inode_uidgid(user_ns, inode)) | |
1508 | user_ns = user_ns->parent; | |
1509 | ||
1510 | if (old != user_ns) { | |
1511 | bprm->mm->user_ns = get_user_ns(user_ns); | |
1512 | put_user_ns(old); | |
1513 | } | |
1514 | } | |
1b5d783c AV |
1515 | } |
1516 | EXPORT_SYMBOL(would_dump); | |
1517 | ||
221af7f8 LT |
1518 | void setup_new_exec(struct linux_binprm * bprm) |
1519 | { | |
df9e4d2c EB |
1520 | /* Setup things that can depend upon the personality */ |
1521 | struct task_struct *me = current; | |
1da177e4 | 1522 | |
df9e4d2c | 1523 | arch_pick_mmap_layout(me->mm, &bprm->rlim_stack); |
d6e71144 | 1524 | |
e9ea1e7f | 1525 | arch_setup_new_exec(); |
1da177e4 | 1526 | |
0551fbd2 BH |
1527 | /* Set the new mm task size. We have to do that late because it may |
1528 | * depend on TIF_32BIT which is only updated in flush_thread() on | |
1529 | * some architectures like powerpc | |
1530 | */ | |
df9e4d2c | 1531 | me->mm->task_size = TASK_SIZE; |
7d503feb EB |
1532 | mutex_unlock(&me->signal->exec_update_mutex); |
1533 | mutex_unlock(&me->signal->cred_guard_mutex); | |
1da177e4 | 1534 | } |
221af7f8 | 1535 | EXPORT_SYMBOL(setup_new_exec); |
1da177e4 | 1536 | |
b8383831 KC |
1537 | /* Runs immediately before start_thread() takes over. */ |
1538 | void finalize_exec(struct linux_binprm *bprm) | |
1539 | { | |
c31dbb14 KC |
1540 | /* Store any stack rlimit changes before starting thread. */ |
1541 | task_lock(current->group_leader); | |
1542 | current->signal->rlim[RLIMIT_STACK] = bprm->rlim_stack; | |
1543 | task_unlock(current->group_leader); | |
b8383831 KC |
1544 | } |
1545 | EXPORT_SYMBOL(finalize_exec); | |
1546 | ||
a2a8474c ON |
1547 | /* |
1548 | * Prepare credentials and lock ->cred_guard_mutex. | |
96ecee29 | 1549 | * setup_new_exec() commits the new creds and drops the lock. |
a2a8474c ON |
1550 | * Or, if exec fails before, free_bprm() should release ->cred and |
1551 | * and unlock. | |
1552 | */ | |
4addd264 | 1553 | static int prepare_bprm_creds(struct linux_binprm *bprm) |
a2a8474c | 1554 | { |
9b1bf12d | 1555 | if (mutex_lock_interruptible(¤t->signal->cred_guard_mutex)) |
a2a8474c ON |
1556 | return -ERESTARTNOINTR; |
1557 | ||
1558 | bprm->cred = prepare_exec_creds(); | |
1559 | if (likely(bprm->cred)) | |
1560 | return 0; | |
1561 | ||
9b1bf12d | 1562 | mutex_unlock(¤t->signal->cred_guard_mutex); |
a2a8474c ON |
1563 | return -ENOMEM; |
1564 | } | |
1565 | ||
c4ad8f98 | 1566 | static void free_bprm(struct linux_binprm *bprm) |
a2a8474c | 1567 | { |
f18ac551 EB |
1568 | if (bprm->mm) { |
1569 | acct_arg_size(bprm, 0); | |
1570 | mmput(bprm->mm); | |
1571 | } | |
a2a8474c ON |
1572 | free_arg_pages(bprm); |
1573 | if (bprm->cred) { | |
9b1bf12d | 1574 | mutex_unlock(¤t->signal->cred_guard_mutex); |
a2a8474c ON |
1575 | abort_creds(bprm->cred); |
1576 | } | |
63e46b95 ON |
1577 | if (bprm->file) { |
1578 | allow_write_access(bprm->file); | |
1579 | fput(bprm->file); | |
1580 | } | |
b8a61c9e EB |
1581 | if (bprm->executable) |
1582 | fput(bprm->executable); | |
b66c5984 KC |
1583 | /* If a binfmt changed the interp, free it. */ |
1584 | if (bprm->interp != bprm->filename) | |
1585 | kfree(bprm->interp); | |
60d9ad1d | 1586 | kfree(bprm->fdpath); |
a2a8474c ON |
1587 | kfree(bprm); |
1588 | } | |
1589 | ||
60d9ad1d | 1590 | static struct linux_binprm *alloc_bprm(int fd, struct filename *filename) |
0a8f36eb EB |
1591 | { |
1592 | struct linux_binprm *bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); | |
60d9ad1d | 1593 | int retval = -ENOMEM; |
0a8f36eb | 1594 | if (!bprm) |
60d9ad1d EB |
1595 | goto out; |
1596 | ||
1597 | if (fd == AT_FDCWD || filename->name[0] == '/') { | |
1598 | bprm->filename = filename->name; | |
1599 | } else { | |
1600 | if (filename->name[0] == '\0') | |
1601 | bprm->fdpath = kasprintf(GFP_KERNEL, "/dev/fd/%d", fd); | |
1602 | else | |
1603 | bprm->fdpath = kasprintf(GFP_KERNEL, "/dev/fd/%d/%s", | |
1604 | fd, filename->name); | |
1605 | if (!bprm->fdpath) | |
1606 | goto out_free; | |
1607 | ||
1608 | bprm->filename = bprm->fdpath; | |
1609 | } | |
1610 | bprm->interp = bprm->filename; | |
f18ac551 EB |
1611 | |
1612 | retval = bprm_mm_init(bprm); | |
1613 | if (retval) | |
1614 | goto out_free; | |
0a8f36eb | 1615 | return bprm; |
60d9ad1d EB |
1616 | |
1617 | out_free: | |
1618 | free_bprm(bprm); | |
1619 | out: | |
1620 | return ERR_PTR(retval); | |
0a8f36eb EB |
1621 | } |
1622 | ||
c2315c18 | 1623 | int bprm_change_interp(const char *interp, struct linux_binprm *bprm) |
b66c5984 KC |
1624 | { |
1625 | /* If a binfmt changed the interp, free it first. */ | |
1626 | if (bprm->interp != bprm->filename) | |
1627 | kfree(bprm->interp); | |
1628 | bprm->interp = kstrdup(interp, GFP_KERNEL); | |
1629 | if (!bprm->interp) | |
1630 | return -ENOMEM; | |
1631 | return 0; | |
1632 | } | |
1633 | EXPORT_SYMBOL(bprm_change_interp); | |
1634 | ||
a6f76f23 DH |
1635 | /* |
1636 | * determine how safe it is to execute the proposed program | |
9b1bf12d | 1637 | * - the caller must hold ->cred_guard_mutex to protect against |
c2e1f2e3 | 1638 | * PTRACE_ATTACH or seccomp thread-sync |
a6f76f23 | 1639 | */ |
9e00cdb0 | 1640 | static void check_unsafe_exec(struct linux_binprm *bprm) |
a6f76f23 | 1641 | { |
0bf2f3ae | 1642 | struct task_struct *p = current, *t; |
f1191b50 | 1643 | unsigned n_fs; |
a6f76f23 | 1644 | |
9227dd2a EB |
1645 | if (p->ptrace) |
1646 | bprm->unsafe |= LSM_UNSAFE_PTRACE; | |
a6f76f23 | 1647 | |
259e5e6c AL |
1648 | /* |
1649 | * This isn't strictly necessary, but it makes it harder for LSMs to | |
1650 | * mess up. | |
1651 | */ | |
1d4457f9 | 1652 | if (task_no_new_privs(current)) |
259e5e6c AL |
1653 | bprm->unsafe |= LSM_UNSAFE_NO_NEW_PRIVS; |
1654 | ||
83f62a2e | 1655 | t = p; |
0bf2f3ae | 1656 | n_fs = 1; |
2a4419b5 | 1657 | spin_lock(&p->fs->lock); |
437f7fdb | 1658 | rcu_read_lock(); |
83f62a2e | 1659 | while_each_thread(p, t) { |
0bf2f3ae DH |
1660 | if (t->fs == p->fs) |
1661 | n_fs++; | |
0bf2f3ae | 1662 | } |
437f7fdb | 1663 | rcu_read_unlock(); |
0bf2f3ae | 1664 | |
9e00cdb0 | 1665 | if (p->fs->users > n_fs) |
a6f76f23 | 1666 | bprm->unsafe |= LSM_UNSAFE_SHARE; |
9e00cdb0 ON |
1667 | else |
1668 | p->fs->in_exec = 1; | |
2a4419b5 | 1669 | spin_unlock(&p->fs->lock); |
a6f76f23 DH |
1670 | } |
1671 | ||
56305aa9 | 1672 | static void bprm_fill_uid(struct linux_binprm *bprm, struct file *file) |
8b01fc86 | 1673 | { |
56305aa9 | 1674 | /* Handle suid and sgid on files */ |
8b01fc86 JH |
1675 | struct inode *inode; |
1676 | unsigned int mode; | |
1677 | kuid_t uid; | |
1678 | kgid_t gid; | |
1679 | ||
56305aa9 | 1680 | if (!mnt_may_suid(file->f_path.mnt)) |
8b01fc86 JH |
1681 | return; |
1682 | ||
1683 | if (task_no_new_privs(current)) | |
1684 | return; | |
1685 | ||
56305aa9 | 1686 | inode = file->f_path.dentry->d_inode; |
8b01fc86 JH |
1687 | mode = READ_ONCE(inode->i_mode); |
1688 | if (!(mode & (S_ISUID|S_ISGID))) | |
1689 | return; | |
1690 | ||
1691 | /* Be careful if suid/sgid is set */ | |
5955102c | 1692 | inode_lock(inode); |
8b01fc86 JH |
1693 | |
1694 | /* reload atomically mode/uid/gid now that lock held */ | |
1695 | mode = inode->i_mode; | |
1696 | uid = inode->i_uid; | |
1697 | gid = inode->i_gid; | |
5955102c | 1698 | inode_unlock(inode); |
8b01fc86 JH |
1699 | |
1700 | /* We ignore suid/sgid if there are no mappings for them in the ns */ | |
1701 | if (!kuid_has_mapping(bprm->cred->user_ns, uid) || | |
1702 | !kgid_has_mapping(bprm->cred->user_ns, gid)) | |
1703 | return; | |
1704 | ||
1705 | if (mode & S_ISUID) { | |
1706 | bprm->per_clear |= PER_CLEAR_ON_SETID; | |
1707 | bprm->cred->euid = uid; | |
1708 | } | |
1709 | ||
1710 | if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { | |
1711 | bprm->per_clear |= PER_CLEAR_ON_SETID; | |
1712 | bprm->cred->egid = gid; | |
1713 | } | |
1714 | } | |
1715 | ||
56305aa9 EB |
1716 | /* |
1717 | * Compute brpm->cred based upon the final binary. | |
1718 | */ | |
1719 | static int bprm_creds_from_file(struct linux_binprm *bprm) | |
1720 | { | |
1721 | /* Compute creds based on which file? */ | |
1722 | struct file *file = bprm->execfd_creds ? bprm->executable : bprm->file; | |
1723 | ||
1724 | bprm_fill_uid(bprm, file); | |
1725 | return security_bprm_creds_from_file(bprm, file); | |
1726 | } | |
1727 | ||
9e00cdb0 ON |
1728 | /* |
1729 | * Fill the binprm structure from the inode. | |
56305aa9 | 1730 | * Read the first BINPRM_BUF_SIZE bytes |
a6f76f23 DH |
1731 | * |
1732 | * This may be called multiple times for binary chains (scripts for example). | |
1da177e4 | 1733 | */ |
8b72ca90 | 1734 | static int prepare_binprm(struct linux_binprm *bprm) |
1da177e4 | 1735 | { |
bdd1d2d3 | 1736 | loff_t pos = 0; |
1da177e4 | 1737 | |
a6f76f23 | 1738 | memset(bprm->buf, 0, BINPRM_BUF_SIZE); |
bdd1d2d3 | 1739 | return kernel_read(bprm->file, bprm->buf, BINPRM_BUF_SIZE, &pos); |
1da177e4 LT |
1740 | } |
1741 | ||
4fc75ff4 NP |
1742 | /* |
1743 | * Arguments are '\0' separated strings found at the location bprm->p | |
1744 | * points to; chop off the first by relocating brpm->p to right after | |
1745 | * the first '\0' encountered. | |
1746 | */ | |
b6a2fea3 | 1747 | int remove_arg_zero(struct linux_binprm *bprm) |
1da177e4 | 1748 | { |
b6a2fea3 OW |
1749 | int ret = 0; |
1750 | unsigned long offset; | |
1751 | char *kaddr; | |
1752 | struct page *page; | |
4fc75ff4 | 1753 | |
b6a2fea3 OW |
1754 | if (!bprm->argc) |
1755 | return 0; | |
1da177e4 | 1756 | |
b6a2fea3 OW |
1757 | do { |
1758 | offset = bprm->p & ~PAGE_MASK; | |
1759 | page = get_arg_page(bprm, bprm->p, 0); | |
1760 | if (!page) { | |
1761 | ret = -EFAULT; | |
1762 | goto out; | |
1763 | } | |
e8e3c3d6 | 1764 | kaddr = kmap_atomic(page); |
4fc75ff4 | 1765 | |
b6a2fea3 OW |
1766 | for (; offset < PAGE_SIZE && kaddr[offset]; |
1767 | offset++, bprm->p++) | |
1768 | ; | |
4fc75ff4 | 1769 | |
e8e3c3d6 | 1770 | kunmap_atomic(kaddr); |
b6a2fea3 | 1771 | put_arg_page(page); |
b6a2fea3 | 1772 | } while (offset == PAGE_SIZE); |
4fc75ff4 | 1773 | |
b6a2fea3 OW |
1774 | bprm->p++; |
1775 | bprm->argc--; | |
1776 | ret = 0; | |
4fc75ff4 | 1777 | |
b6a2fea3 OW |
1778 | out: |
1779 | return ret; | |
1da177e4 | 1780 | } |
1da177e4 LT |
1781 | EXPORT_SYMBOL(remove_arg_zero); |
1782 | ||
cb7b6b1c | 1783 | #define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e)) |
1da177e4 LT |
1784 | /* |
1785 | * cycle the list of binary formats handler, until one recognizes the image | |
1786 | */ | |
bc2bf338 | 1787 | static int search_binary_handler(struct linux_binprm *bprm) |
1da177e4 | 1788 | { |
cb7b6b1c | 1789 | bool need_retry = IS_ENABLED(CONFIG_MODULES); |
1da177e4 | 1790 | struct linux_binfmt *fmt; |
cb7b6b1c | 1791 | int retval; |
1da177e4 | 1792 | |
8b72ca90 EB |
1793 | retval = prepare_binprm(bprm); |
1794 | if (retval < 0) | |
1795 | return retval; | |
d7402698 | 1796 | |
1da177e4 LT |
1797 | retval = security_bprm_check(bprm); |
1798 | if (retval) | |
1799 | return retval; | |
1800 | ||
1da177e4 | 1801 | retval = -ENOENT; |
cb7b6b1c ON |
1802 | retry: |
1803 | read_lock(&binfmt_lock); | |
1804 | list_for_each_entry(fmt, &formats, lh) { | |
1805 | if (!try_module_get(fmt->module)) | |
1806 | continue; | |
1807 | read_unlock(&binfmt_lock); | |
d53ddd01 | 1808 | |
cb7b6b1c | 1809 | retval = fmt->load_binary(bprm); |
d53ddd01 | 1810 | |
19d860a1 AV |
1811 | read_lock(&binfmt_lock); |
1812 | put_binfmt(fmt); | |
bc2bf338 | 1813 | if (bprm->point_of_no_return || (retval != -ENOEXEC)) { |
19d860a1 | 1814 | read_unlock(&binfmt_lock); |
cb7b6b1c | 1815 | return retval; |
1da177e4 | 1816 | } |
1da177e4 | 1817 | } |
cb7b6b1c ON |
1818 | read_unlock(&binfmt_lock); |
1819 | ||
19d860a1 | 1820 | if (need_retry) { |
cb7b6b1c ON |
1821 | if (printable(bprm->buf[0]) && printable(bprm->buf[1]) && |
1822 | printable(bprm->buf[2]) && printable(bprm->buf[3])) | |
1823 | return retval; | |
4e0621a0 ON |
1824 | if (request_module("binfmt-%04x", *(ushort *)(bprm->buf + 2)) < 0) |
1825 | return retval; | |
cb7b6b1c ON |
1826 | need_retry = false; |
1827 | goto retry; | |
1828 | } | |
1829 | ||
1da177e4 LT |
1830 | return retval; |
1831 | } | |
1da177e4 | 1832 | |
5d1baf3b ON |
1833 | static int exec_binprm(struct linux_binprm *bprm) |
1834 | { | |
1835 | pid_t old_pid, old_vpid; | |
bc2bf338 | 1836 | int ret, depth; |
5d1baf3b ON |
1837 | |
1838 | /* Need to fetch pid before load_binary changes it */ | |
1839 | old_pid = current->pid; | |
1840 | rcu_read_lock(); | |
1841 | old_vpid = task_pid_nr_ns(current, task_active_pid_ns(current->parent)); | |
1842 | rcu_read_unlock(); | |
1843 | ||
bc2bf338 EB |
1844 | /* This allows 4 levels of binfmt rewrites before failing hard. */ |
1845 | for (depth = 0;; depth++) { | |
1846 | struct file *exec; | |
1847 | if (depth > 5) | |
1848 | return -ELOOP; | |
1849 | ||
1850 | ret = search_binary_handler(bprm); | |
1851 | if (ret < 0) | |
1852 | return ret; | |
1853 | if (!bprm->interpreter) | |
1854 | break; | |
1855 | ||
1856 | exec = bprm->file; | |
1857 | bprm->file = bprm->interpreter; | |
1858 | bprm->interpreter = NULL; | |
1859 | ||
1860 | allow_write_access(exec); | |
1861 | if (unlikely(bprm->have_execfd)) { | |
1862 | if (bprm->executable) { | |
1863 | fput(exec); | |
1864 | return -ENOEXEC; | |
1865 | } | |
1866 | bprm->executable = exec; | |
1867 | } else | |
1868 | fput(exec); | |
5d1baf3b ON |
1869 | } |
1870 | ||
bc2bf338 EB |
1871 | audit_bprm(bprm); |
1872 | trace_sched_process_exec(current, old_pid, bprm); | |
1873 | ptrace_event(PTRACE_EVENT_EXEC, old_vpid); | |
1874 | proc_exec_connector(current); | |
1875 | return 0; | |
5d1baf3b ON |
1876 | } |
1877 | ||
1da177e4 LT |
1878 | /* |
1879 | * sys_execve() executes a new program. | |
1880 | */ | |
0c9cdff0 EB |
1881 | static int bprm_execve(struct linux_binprm *bprm, |
1882 | int fd, struct filename *filename, int flags) | |
1da177e4 | 1883 | { |
25cf336d | 1884 | struct file *file; |
3b125388 | 1885 | struct files_struct *displaced; |
1da177e4 | 1886 | int retval; |
72fa5997 | 1887 | |
0a8f36eb EB |
1888 | retval = unshare_files(&displaced); |
1889 | if (retval) | |
0c9cdff0 | 1890 | return retval; |
1da177e4 | 1891 | |
a2a8474c ON |
1892 | retval = prepare_bprm_creds(bprm); |
1893 | if (retval) | |
0a8f36eb | 1894 | goto out_files; |
498052bb | 1895 | |
9e00cdb0 | 1896 | check_unsafe_exec(bprm); |
a2a8474c | 1897 | current->in_execve = 1; |
a6f76f23 | 1898 | |
25cf336d | 1899 | file = do_open_execat(fd, filename, flags); |
1da177e4 LT |
1900 | retval = PTR_ERR(file); |
1901 | if (IS_ERR(file)) | |
498052bb | 1902 | goto out_unmark; |
1da177e4 LT |
1903 | |
1904 | sched_exec(); | |
1905 | ||
1da177e4 | 1906 | bprm->file = file; |
60d9ad1d EB |
1907 | /* |
1908 | * Record that a name derived from an O_CLOEXEC fd will be | |
1909 | * inaccessible after exec. Relies on having exclusive access to | |
1910 | * current->files (due to unshare_files above). | |
1911 | */ | |
1912 | if (bprm->fdpath && | |
1913 | close_on_exec(fd, rcu_dereference_raw(current->files->fdt))) | |
1914 | bprm->interp_flags |= BINPRM_FLAGS_PATH_INACCESSIBLE; | |
1da177e4 | 1915 | |
b8bff599 EB |
1916 | /* Set the unchanging part of bprm->cred */ |
1917 | retval = security_bprm_creds_for_exec(bprm); | |
1918 | if (retval) | |
1da177e4 LT |
1919 | goto out; |
1920 | ||
5d1baf3b | 1921 | retval = exec_binprm(bprm); |
a6f76f23 DH |
1922 | if (retval < 0) |
1923 | goto out; | |
1da177e4 | 1924 | |
a6f76f23 | 1925 | /* execve succeeded */ |
498052bb | 1926 | current->fs->in_exec = 0; |
f9ce1f1c | 1927 | current->in_execve = 0; |
d7822b1e | 1928 | rseq_execve(current); |
a6f76f23 | 1929 | acct_update_integrals(current); |
16d51a59 | 1930 | task_numa_free(current, false); |
a6f76f23 DH |
1931 | if (displaced) |
1932 | put_files_struct(displaced); | |
1933 | return retval; | |
1da177e4 | 1934 | |
a6f76f23 | 1935 | out: |
8890b293 EB |
1936 | /* |
1937 | * If past the point of no return ensure the the code never | |
1938 | * returns to the userspace process. Use an existing fatal | |
1939 | * signal if present otherwise terminate the process with | |
1940 | * SIGSEGV. | |
1941 | */ | |
1942 | if (bprm->point_of_no_return && !fatal_signal_pending(current)) | |
1943 | force_sigsegv(SIGSEGV); | |
1da177e4 | 1944 | |
498052bb | 1945 | out_unmark: |
9e00cdb0 | 1946 | current->fs->in_exec = 0; |
f9ce1f1c | 1947 | current->in_execve = 0; |
a6f76f23 | 1948 | |
0a8f36eb EB |
1949 | out_files: |
1950 | if (displaced) | |
1951 | reset_files_struct(displaced); | |
0c9cdff0 EB |
1952 | |
1953 | return retval; | |
1954 | } | |
1955 | ||
1956 | static int do_execveat_common(int fd, struct filename *filename, | |
1957 | struct user_arg_ptr argv, | |
1958 | struct user_arg_ptr envp, | |
1959 | int flags) | |
1960 | { | |
1961 | struct linux_binprm *bprm; | |
1962 | int retval; | |
1963 | ||
1964 | if (IS_ERR(filename)) | |
1965 | return PTR_ERR(filename); | |
1966 | ||
1967 | /* | |
1968 | * We move the actual failure in case of RLIMIT_NPROC excess from | |
1969 | * set*uid() to execve() because too many poorly written programs | |
1970 | * don't check setuid() return code. Here we additionally recheck | |
1971 | * whether NPROC limit is still exceeded. | |
1972 | */ | |
1973 | if ((current->flags & PF_NPROC_EXCEEDED) && | |
1974 | atomic_read(¤t_user()->processes) > rlimit(RLIMIT_NPROC)) { | |
1975 | retval = -EAGAIN; | |
1976 | goto out_ret; | |
1977 | } | |
1978 | ||
1979 | /* We're below the limit (still or again), so we don't want to make | |
1980 | * further execve() calls fail. */ | |
1981 | current->flags &= ~PF_NPROC_EXCEEDED; | |
1982 | ||
1983 | bprm = alloc_bprm(fd, filename); | |
1984 | if (IS_ERR(bprm)) { | |
1985 | retval = PTR_ERR(bprm); | |
1986 | goto out_ret; | |
1987 | } | |
1988 | ||
d8b9cd54 EB |
1989 | retval = count(argv, MAX_ARG_STRINGS); |
1990 | if (retval < 0) | |
1991 | goto out_free; | |
1992 | bprm->argc = retval; | |
1993 | ||
1994 | retval = count(envp, MAX_ARG_STRINGS); | |
1995 | if (retval < 0) | |
1996 | goto out_free; | |
1997 | bprm->envc = retval; | |
1998 | ||
1999 | retval = bprm_stack_limits(bprm); | |
0c9cdff0 EB |
2000 | if (retval < 0) |
2001 | goto out_free; | |
2002 | ||
2003 | retval = copy_string_kernel(bprm->filename, bprm); | |
2004 | if (retval < 0) | |
2005 | goto out_free; | |
2006 | bprm->exec = bprm->p; | |
2007 | ||
2008 | retval = copy_strings(bprm->envc, envp, bprm); | |
2009 | if (retval < 0) | |
2010 | goto out_free; | |
2011 | ||
2012 | retval = copy_strings(bprm->argc, argv, bprm); | |
2013 | if (retval < 0) | |
2014 | goto out_free; | |
2015 | ||
2016 | retval = bprm_execve(bprm, fd, filename, flags); | |
a6f76f23 | 2017 | out_free: |
08a6fac1 | 2018 | free_bprm(bprm); |
1da177e4 LT |
2019 | |
2020 | out_ret: | |
25cf336d | 2021 | putname(filename); |
1da177e4 LT |
2022 | return retval; |
2023 | } | |
2024 | ||
be619f7f EB |
2025 | int kernel_execve(const char *kernel_filename, |
2026 | const char *const *argv, const char *const *envp) | |
2027 | { | |
2028 | struct filename *filename; | |
2029 | struct linux_binprm *bprm; | |
2030 | int fd = AT_FDCWD; | |
2031 | int retval; | |
2032 | ||
2033 | filename = getname_kernel(kernel_filename); | |
2034 | if (IS_ERR(filename)) | |
2035 | return PTR_ERR(filename); | |
2036 | ||
2037 | bprm = alloc_bprm(fd, filename); | |
2038 | if (IS_ERR(bprm)) { | |
2039 | retval = PTR_ERR(bprm); | |
2040 | goto out_ret; | |
2041 | } | |
2042 | ||
2043 | retval = count_strings_kernel(argv); | |
2044 | if (retval < 0) | |
2045 | goto out_free; | |
2046 | bprm->argc = retval; | |
2047 | ||
2048 | retval = count_strings_kernel(envp); | |
2049 | if (retval < 0) | |
2050 | goto out_free; | |
2051 | bprm->envc = retval; | |
2052 | ||
2053 | retval = bprm_stack_limits(bprm); | |
2054 | if (retval < 0) | |
2055 | goto out_free; | |
2056 | ||
2057 | retval = copy_string_kernel(bprm->filename, bprm); | |
2058 | if (retval < 0) | |
2059 | goto out_free; | |
2060 | bprm->exec = bprm->p; | |
2061 | ||
2062 | retval = copy_strings_kernel(bprm->envc, envp, bprm); | |
2063 | if (retval < 0) | |
2064 | goto out_free; | |
2065 | ||
2066 | retval = copy_strings_kernel(bprm->argc, argv, bprm); | |
2067 | if (retval < 0) | |
2068 | goto out_free; | |
2069 | ||
2070 | retval = bprm_execve(bprm, fd, filename, 0); | |
2071 | out_free: | |
2072 | free_bprm(bprm); | |
2073 | out_ret: | |
2074 | putname(filename); | |
2075 | return retval; | |
2076 | } | |
2077 | ||
2078 | static int do_execve(struct filename *filename, | |
ba2d0162 | 2079 | const char __user *const __user *__argv, |
da3d4c5f | 2080 | const char __user *const __user *__envp) |
ba2d0162 | 2081 | { |
0e028465 ON |
2082 | struct user_arg_ptr argv = { .ptr.native = __argv }; |
2083 | struct user_arg_ptr envp = { .ptr.native = __envp }; | |
51f39a1f DD |
2084 | return do_execveat_common(AT_FDCWD, filename, argv, envp, 0); |
2085 | } | |
2086 | ||
be619f7f | 2087 | static int do_execveat(int fd, struct filename *filename, |
51f39a1f DD |
2088 | const char __user *const __user *__argv, |
2089 | const char __user *const __user *__envp, | |
2090 | int flags) | |
2091 | { | |
2092 | struct user_arg_ptr argv = { .ptr.native = __argv }; | |
2093 | struct user_arg_ptr envp = { .ptr.native = __envp }; | |
2094 | ||
2095 | return do_execveat_common(fd, filename, argv, envp, flags); | |
0e028465 ON |
2096 | } |
2097 | ||
2098 | #ifdef CONFIG_COMPAT | |
c4ad8f98 | 2099 | static int compat_do_execve(struct filename *filename, |
38b983b3 | 2100 | const compat_uptr_t __user *__argv, |
d03d26e5 | 2101 | const compat_uptr_t __user *__envp) |
0e028465 ON |
2102 | { |
2103 | struct user_arg_ptr argv = { | |
2104 | .is_compat = true, | |
2105 | .ptr.compat = __argv, | |
2106 | }; | |
2107 | struct user_arg_ptr envp = { | |
2108 | .is_compat = true, | |
2109 | .ptr.compat = __envp, | |
2110 | }; | |
51f39a1f DD |
2111 | return do_execveat_common(AT_FDCWD, filename, argv, envp, 0); |
2112 | } | |
2113 | ||
2114 | static int compat_do_execveat(int fd, struct filename *filename, | |
2115 | const compat_uptr_t __user *__argv, | |
2116 | const compat_uptr_t __user *__envp, | |
2117 | int flags) | |
2118 | { | |
2119 | struct user_arg_ptr argv = { | |
2120 | .is_compat = true, | |
2121 | .ptr.compat = __argv, | |
2122 | }; | |
2123 | struct user_arg_ptr envp = { | |
2124 | .is_compat = true, | |
2125 | .ptr.compat = __envp, | |
2126 | }; | |
2127 | return do_execveat_common(fd, filename, argv, envp, flags); | |
ba2d0162 | 2128 | } |
0e028465 | 2129 | #endif |
ba2d0162 | 2130 | |
964ee7df | 2131 | void set_binfmt(struct linux_binfmt *new) |
1da177e4 | 2132 | { |
801460d0 HS |
2133 | struct mm_struct *mm = current->mm; |
2134 | ||
2135 | if (mm->binfmt) | |
2136 | module_put(mm->binfmt->module); | |
1da177e4 | 2137 | |
801460d0 | 2138 | mm->binfmt = new; |
964ee7df ON |
2139 | if (new) |
2140 | __module_get(new->module); | |
1da177e4 | 2141 | } |
1da177e4 LT |
2142 | EXPORT_SYMBOL(set_binfmt); |
2143 | ||
6c5d5238 | 2144 | /* |
7288e118 | 2145 | * set_dumpable stores three-value SUID_DUMP_* into mm->flags. |
6c5d5238 KH |
2146 | */ |
2147 | void set_dumpable(struct mm_struct *mm, int value) | |
2148 | { | |
7288e118 ON |
2149 | if (WARN_ON((unsigned)value > SUID_DUMP_ROOT)) |
2150 | return; | |
2151 | ||
26e15225 | 2152 | set_mask_bits(&mm->flags, MMF_DUMPABLE_MASK, value); |
6c5d5238 | 2153 | } |
6c5d5238 | 2154 | |
38b983b3 AV |
2155 | SYSCALL_DEFINE3(execve, |
2156 | const char __user *, filename, | |
2157 | const char __user *const __user *, argv, | |
2158 | const char __user *const __user *, envp) | |
2159 | { | |
c4ad8f98 | 2160 | return do_execve(getname(filename), argv, envp); |
38b983b3 | 2161 | } |
51f39a1f DD |
2162 | |
2163 | SYSCALL_DEFINE5(execveat, | |
2164 | int, fd, const char __user *, filename, | |
2165 | const char __user *const __user *, argv, | |
2166 | const char __user *const __user *, envp, | |
2167 | int, flags) | |
2168 | { | |
2169 | int lookup_flags = (flags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0; | |
2170 | ||
2171 | return do_execveat(fd, | |
2172 | getname_flags(filename, lookup_flags, NULL), | |
2173 | argv, envp, flags); | |
2174 | } | |
2175 | ||
38b983b3 | 2176 | #ifdef CONFIG_COMPAT |
625b1d7e HC |
2177 | COMPAT_SYSCALL_DEFINE3(execve, const char __user *, filename, |
2178 | const compat_uptr_t __user *, argv, | |
2179 | const compat_uptr_t __user *, envp) | |
38b983b3 | 2180 | { |
c4ad8f98 | 2181 | return compat_do_execve(getname(filename), argv, envp); |
38b983b3 | 2182 | } |
51f39a1f DD |
2183 | |
2184 | COMPAT_SYSCALL_DEFINE5(execveat, int, fd, | |
2185 | const char __user *, filename, | |
2186 | const compat_uptr_t __user *, argv, | |
2187 | const compat_uptr_t __user *, envp, | |
2188 | int, flags) | |
2189 | { | |
2190 | int lookup_flags = (flags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0; | |
2191 | ||
2192 | return compat_do_execveat(fd, | |
2193 | getname_flags(filename, lookup_flags, NULL), | |
2194 | argv, envp, flags); | |
2195 | } | |
38b983b3 | 2196 | #endif |