Commit | Line | Data |
---|---|---|
1da177e4 LT |
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 | ||
1da177e4 LT |
25 | #include <linux/slab.h> |
26 | #include <linux/file.h> | |
27 | #include <linux/mman.h> | |
28 | #include <linux/a.out.h> | |
29 | #include <linux/stat.h> | |
30 | #include <linux/fcntl.h> | |
31 | #include <linux/smp_lock.h> | |
74aadce9 | 32 | #include <linux/string.h> |
1da177e4 LT |
33 | #include <linux/init.h> |
34 | #include <linux/pagemap.h> | |
35 | #include <linux/highmem.h> | |
36 | #include <linux/spinlock.h> | |
37 | #include <linux/key.h> | |
38 | #include <linux/personality.h> | |
39 | #include <linux/binfmts.h> | |
40 | #include <linux/swap.h> | |
41 | #include <linux/utsname.h> | |
84d73786 | 42 | #include <linux/pid_namespace.h> |
1da177e4 LT |
43 | #include <linux/module.h> |
44 | #include <linux/namei.h> | |
45 | #include <linux/proc_fs.h> | |
46 | #include <linux/ptrace.h> | |
47 | #include <linux/mount.h> | |
48 | #include <linux/security.h> | |
49 | #include <linux/syscalls.h> | |
50 | #include <linux/rmap.h> | |
8f0ab514 | 51 | #include <linux/tsacct_kern.h> |
9f46080c | 52 | #include <linux/cn_proc.h> |
473ae30b | 53 | #include <linux/audit.h> |
1da177e4 LT |
54 | |
55 | #include <asm/uaccess.h> | |
56 | #include <asm/mmu_context.h> | |
b6a2fea3 | 57 | #include <asm/tlb.h> |
1da177e4 LT |
58 | |
59 | #ifdef CONFIG_KMOD | |
60 | #include <linux/kmod.h> | |
61 | #endif | |
62 | ||
63 | int core_uses_pid; | |
71ce92f3 | 64 | char core_pattern[CORENAME_MAX_SIZE] = "core"; |
d6e71144 AC |
65 | int suid_dumpable = 0; |
66 | ||
1da177e4 LT |
67 | /* The maximal length of core_pattern is also specified in sysctl.c */ |
68 | ||
e4dc1b14 | 69 | static LIST_HEAD(formats); |
1da177e4 LT |
70 | static DEFINE_RWLOCK(binfmt_lock); |
71 | ||
72 | int register_binfmt(struct linux_binfmt * fmt) | |
73 | { | |
1da177e4 LT |
74 | if (!fmt) |
75 | return -EINVAL; | |
1da177e4 | 76 | write_lock(&binfmt_lock); |
e4dc1b14 | 77 | list_add(&fmt->lh, &formats); |
1da177e4 LT |
78 | write_unlock(&binfmt_lock); |
79 | return 0; | |
80 | } | |
81 | ||
82 | EXPORT_SYMBOL(register_binfmt); | |
83 | ||
f6b450d4 | 84 | void unregister_binfmt(struct linux_binfmt * fmt) |
1da177e4 | 85 | { |
1da177e4 | 86 | write_lock(&binfmt_lock); |
e4dc1b14 | 87 | list_del(&fmt->lh); |
1da177e4 | 88 | write_unlock(&binfmt_lock); |
1da177e4 LT |
89 | } |
90 | ||
91 | EXPORT_SYMBOL(unregister_binfmt); | |
92 | ||
93 | static inline void put_binfmt(struct linux_binfmt * fmt) | |
94 | { | |
95 | module_put(fmt->module); | |
96 | } | |
97 | ||
98 | /* | |
99 | * Note that a shared library must be both readable and executable due to | |
100 | * security reasons. | |
101 | * | |
102 | * Also note that we take the address to load from from the file itself. | |
103 | */ | |
104 | asmlinkage long sys_uselib(const char __user * library) | |
105 | { | |
106 | struct file * file; | |
107 | struct nameidata nd; | |
108 | int error; | |
109 | ||
b500531e | 110 | error = __user_path_lookup_open(library, LOOKUP_FOLLOW, &nd, FMODE_READ|FMODE_EXEC); |
1da177e4 LT |
111 | if (error) |
112 | goto out; | |
113 | ||
114 | error = -EINVAL; | |
115 | if (!S_ISREG(nd.dentry->d_inode->i_mode)) | |
116 | goto exit; | |
117 | ||
e4543edd | 118 | error = vfs_permission(&nd, MAY_READ | MAY_EXEC); |
1da177e4 LT |
119 | if (error) |
120 | goto exit; | |
121 | ||
abe8be3a | 122 | file = nameidata_to_filp(&nd, O_RDONLY|O_LARGEFILE); |
1da177e4 LT |
123 | error = PTR_ERR(file); |
124 | if (IS_ERR(file)) | |
125 | goto out; | |
126 | ||
127 | error = -ENOEXEC; | |
128 | if(file->f_op) { | |
129 | struct linux_binfmt * fmt; | |
130 | ||
131 | read_lock(&binfmt_lock); | |
e4dc1b14 | 132 | list_for_each_entry(fmt, &formats, lh) { |
1da177e4 LT |
133 | if (!fmt->load_shlib) |
134 | continue; | |
135 | if (!try_module_get(fmt->module)) | |
136 | continue; | |
137 | read_unlock(&binfmt_lock); | |
138 | error = fmt->load_shlib(file); | |
139 | read_lock(&binfmt_lock); | |
140 | put_binfmt(fmt); | |
141 | if (error != -ENOEXEC) | |
142 | break; | |
143 | } | |
144 | read_unlock(&binfmt_lock); | |
145 | } | |
146 | fput(file); | |
147 | out: | |
148 | return error; | |
149 | exit: | |
834f2a4a | 150 | release_open_intent(&nd); |
1da177e4 LT |
151 | path_release(&nd); |
152 | goto out; | |
153 | } | |
154 | ||
b6a2fea3 OW |
155 | #ifdef CONFIG_MMU |
156 | ||
157 | static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, | |
158 | int write) | |
159 | { | |
160 | struct page *page; | |
161 | int ret; | |
162 | ||
163 | #ifdef CONFIG_STACK_GROWSUP | |
164 | if (write) { | |
165 | ret = expand_stack_downwards(bprm->vma, pos); | |
166 | if (ret < 0) | |
167 | return NULL; | |
168 | } | |
169 | #endif | |
170 | ret = get_user_pages(current, bprm->mm, pos, | |
171 | 1, write, 1, &page, NULL); | |
172 | if (ret <= 0) | |
173 | return NULL; | |
174 | ||
175 | if (write) { | |
176 | struct rlimit *rlim = current->signal->rlim; | |
177 | unsigned long size = bprm->vma->vm_end - bprm->vma->vm_start; | |
178 | ||
179 | /* | |
180 | * Limit to 1/4-th the stack size for the argv+env strings. | |
181 | * This ensures that: | |
182 | * - the remaining binfmt code will not run out of stack space, | |
183 | * - the program will have a reasonable amount of stack left | |
184 | * to work from. | |
185 | */ | |
186 | if (size > rlim[RLIMIT_STACK].rlim_cur / 4) { | |
187 | put_page(page); | |
188 | return NULL; | |
189 | } | |
190 | } | |
191 | ||
192 | return page; | |
193 | } | |
194 | ||
195 | static void put_arg_page(struct page *page) | |
196 | { | |
197 | put_page(page); | |
198 | } | |
199 | ||
200 | static void free_arg_page(struct linux_binprm *bprm, int i) | |
201 | { | |
202 | } | |
203 | ||
204 | static void free_arg_pages(struct linux_binprm *bprm) | |
205 | { | |
206 | } | |
207 | ||
208 | static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, | |
209 | struct page *page) | |
210 | { | |
211 | flush_cache_page(bprm->vma, pos, page_to_pfn(page)); | |
212 | } | |
213 | ||
214 | static int __bprm_mm_init(struct linux_binprm *bprm) | |
215 | { | |
216 | int err = -ENOMEM; | |
217 | struct vm_area_struct *vma = NULL; | |
218 | struct mm_struct *mm = bprm->mm; | |
219 | ||
220 | bprm->vma = vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL); | |
221 | if (!vma) | |
222 | goto err; | |
223 | ||
224 | down_write(&mm->mmap_sem); | |
225 | vma->vm_mm = mm; | |
226 | ||
227 | /* | |
228 | * Place the stack at the largest stack address the architecture | |
229 | * supports. Later, we'll move this to an appropriate place. We don't | |
230 | * use STACK_TOP because that can depend on attributes which aren't | |
231 | * configured yet. | |
232 | */ | |
233 | vma->vm_end = STACK_TOP_MAX; | |
234 | vma->vm_start = vma->vm_end - PAGE_SIZE; | |
235 | ||
236 | vma->vm_flags = VM_STACK_FLAGS; | |
3ed75eb8 | 237 | vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); |
b6a2fea3 OW |
238 | err = insert_vm_struct(mm, vma); |
239 | if (err) { | |
240 | up_write(&mm->mmap_sem); | |
241 | goto err; | |
242 | } | |
243 | ||
244 | mm->stack_vm = mm->total_vm = 1; | |
245 | up_write(&mm->mmap_sem); | |
246 | ||
247 | bprm->p = vma->vm_end - sizeof(void *); | |
248 | ||
249 | return 0; | |
250 | ||
251 | err: | |
252 | if (vma) { | |
253 | bprm->vma = NULL; | |
254 | kmem_cache_free(vm_area_cachep, vma); | |
255 | } | |
256 | ||
257 | return err; | |
258 | } | |
259 | ||
260 | static bool valid_arg_len(struct linux_binprm *bprm, long len) | |
261 | { | |
262 | return len <= MAX_ARG_STRLEN; | |
263 | } | |
264 | ||
265 | #else | |
266 | ||
267 | static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, | |
268 | int write) | |
269 | { | |
270 | struct page *page; | |
271 | ||
272 | page = bprm->page[pos / PAGE_SIZE]; | |
273 | if (!page && write) { | |
274 | page = alloc_page(GFP_HIGHUSER|__GFP_ZERO); | |
275 | if (!page) | |
276 | return NULL; | |
277 | bprm->page[pos / PAGE_SIZE] = page; | |
278 | } | |
279 | ||
280 | return page; | |
281 | } | |
282 | ||
283 | static void put_arg_page(struct page *page) | |
284 | { | |
285 | } | |
286 | ||
287 | static void free_arg_page(struct linux_binprm *bprm, int i) | |
288 | { | |
289 | if (bprm->page[i]) { | |
290 | __free_page(bprm->page[i]); | |
291 | bprm->page[i] = NULL; | |
292 | } | |
293 | } | |
294 | ||
295 | static void free_arg_pages(struct linux_binprm *bprm) | |
296 | { | |
297 | int i; | |
298 | ||
299 | for (i = 0; i < MAX_ARG_PAGES; i++) | |
300 | free_arg_page(bprm, i); | |
301 | } | |
302 | ||
303 | static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, | |
304 | struct page *page) | |
305 | { | |
306 | } | |
307 | ||
308 | static int __bprm_mm_init(struct linux_binprm *bprm) | |
309 | { | |
310 | bprm->p = PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *); | |
311 | return 0; | |
312 | } | |
313 | ||
314 | static bool valid_arg_len(struct linux_binprm *bprm, long len) | |
315 | { | |
316 | return len <= bprm->p; | |
317 | } | |
318 | ||
319 | #endif /* CONFIG_MMU */ | |
320 | ||
321 | /* | |
322 | * Create a new mm_struct and populate it with a temporary stack | |
323 | * vm_area_struct. We don't have enough context at this point to set the stack | |
324 | * flags, permissions, and offset, so we use temporary values. We'll update | |
325 | * them later in setup_arg_pages(). | |
326 | */ | |
327 | int bprm_mm_init(struct linux_binprm *bprm) | |
328 | { | |
329 | int err; | |
330 | struct mm_struct *mm = NULL; | |
331 | ||
332 | bprm->mm = mm = mm_alloc(); | |
333 | err = -ENOMEM; | |
334 | if (!mm) | |
335 | goto err; | |
336 | ||
337 | err = init_new_context(current, mm); | |
338 | if (err) | |
339 | goto err; | |
340 | ||
341 | err = __bprm_mm_init(bprm); | |
342 | if (err) | |
343 | goto err; | |
344 | ||
345 | return 0; | |
346 | ||
347 | err: | |
348 | if (mm) { | |
349 | bprm->mm = NULL; | |
350 | mmdrop(mm); | |
351 | } | |
352 | ||
353 | return err; | |
354 | } | |
355 | ||
1da177e4 LT |
356 | /* |
357 | * count() counts the number of strings in array ARGV. | |
358 | */ | |
359 | static int count(char __user * __user * argv, int max) | |
360 | { | |
361 | int i = 0; | |
362 | ||
363 | if (argv != NULL) { | |
364 | for (;;) { | |
365 | char __user * p; | |
366 | ||
367 | if (get_user(p, argv)) | |
368 | return -EFAULT; | |
369 | if (!p) | |
370 | break; | |
371 | argv++; | |
372 | if(++i > max) | |
373 | return -E2BIG; | |
374 | cond_resched(); | |
375 | } | |
376 | } | |
377 | return i; | |
378 | } | |
379 | ||
380 | /* | |
b6a2fea3 OW |
381 | * 'copy_strings()' copies argument/environment strings from the old |
382 | * processes's memory to the new process's stack. The call to get_user_pages() | |
383 | * ensures the destination page is created and not swapped out. | |
1da177e4 | 384 | */ |
75c96f85 AB |
385 | static int copy_strings(int argc, char __user * __user * argv, |
386 | struct linux_binprm *bprm) | |
1da177e4 LT |
387 | { |
388 | struct page *kmapped_page = NULL; | |
389 | char *kaddr = NULL; | |
b6a2fea3 | 390 | unsigned long kpos = 0; |
1da177e4 LT |
391 | int ret; |
392 | ||
393 | while (argc-- > 0) { | |
394 | char __user *str; | |
395 | int len; | |
396 | unsigned long pos; | |
397 | ||
398 | if (get_user(str, argv+argc) || | |
b6a2fea3 | 399 | !(len = strnlen_user(str, MAX_ARG_STRLEN))) { |
1da177e4 LT |
400 | ret = -EFAULT; |
401 | goto out; | |
402 | } | |
403 | ||
b6a2fea3 | 404 | if (!valid_arg_len(bprm, len)) { |
1da177e4 LT |
405 | ret = -E2BIG; |
406 | goto out; | |
407 | } | |
408 | ||
b6a2fea3 | 409 | /* We're going to work our way backwords. */ |
1da177e4 | 410 | pos = bprm->p; |
b6a2fea3 OW |
411 | str += len; |
412 | bprm->p -= len; | |
1da177e4 LT |
413 | |
414 | while (len > 0) { | |
1da177e4 | 415 | int offset, bytes_to_copy; |
1da177e4 LT |
416 | |
417 | offset = pos % PAGE_SIZE; | |
b6a2fea3 OW |
418 | if (offset == 0) |
419 | offset = PAGE_SIZE; | |
420 | ||
421 | bytes_to_copy = offset; | |
422 | if (bytes_to_copy > len) | |
423 | bytes_to_copy = len; | |
424 | ||
425 | offset -= bytes_to_copy; | |
426 | pos -= bytes_to_copy; | |
427 | str -= bytes_to_copy; | |
428 | len -= bytes_to_copy; | |
429 | ||
430 | if (!kmapped_page || kpos != (pos & PAGE_MASK)) { | |
431 | struct page *page; | |
432 | ||
433 | page = get_arg_page(bprm, pos, 1); | |
1da177e4 | 434 | if (!page) { |
b6a2fea3 | 435 | ret = -E2BIG; |
1da177e4 LT |
436 | goto out; |
437 | } | |
1da177e4 | 438 | |
b6a2fea3 OW |
439 | if (kmapped_page) { |
440 | flush_kernel_dcache_page(kmapped_page); | |
1da177e4 | 441 | kunmap(kmapped_page); |
b6a2fea3 OW |
442 | put_arg_page(kmapped_page); |
443 | } | |
1da177e4 LT |
444 | kmapped_page = page; |
445 | kaddr = kmap(kmapped_page); | |
b6a2fea3 OW |
446 | kpos = pos & PAGE_MASK; |
447 | flush_arg_page(bprm, kpos, kmapped_page); | |
1da177e4 | 448 | } |
b6a2fea3 | 449 | if (copy_from_user(kaddr+offset, str, bytes_to_copy)) { |
1da177e4 LT |
450 | ret = -EFAULT; |
451 | goto out; | |
452 | } | |
1da177e4 LT |
453 | } |
454 | } | |
455 | ret = 0; | |
456 | out: | |
b6a2fea3 OW |
457 | if (kmapped_page) { |
458 | flush_kernel_dcache_page(kmapped_page); | |
1da177e4 | 459 | kunmap(kmapped_page); |
b6a2fea3 OW |
460 | put_arg_page(kmapped_page); |
461 | } | |
1da177e4 LT |
462 | return ret; |
463 | } | |
464 | ||
465 | /* | |
466 | * Like copy_strings, but get argv and its values from kernel memory. | |
467 | */ | |
468 | int copy_strings_kernel(int argc,char ** argv, struct linux_binprm *bprm) | |
469 | { | |
470 | int r; | |
471 | mm_segment_t oldfs = get_fs(); | |
472 | set_fs(KERNEL_DS); | |
473 | r = copy_strings(argc, (char __user * __user *)argv, bprm); | |
474 | set_fs(oldfs); | |
475 | return r; | |
476 | } | |
1da177e4 LT |
477 | EXPORT_SYMBOL(copy_strings_kernel); |
478 | ||
479 | #ifdef CONFIG_MMU | |
b6a2fea3 | 480 | |
1da177e4 | 481 | /* |
b6a2fea3 OW |
482 | * During bprm_mm_init(), we create a temporary stack at STACK_TOP_MAX. Once |
483 | * the binfmt code determines where the new stack should reside, we shift it to | |
484 | * its final location. The process proceeds as follows: | |
1da177e4 | 485 | * |
b6a2fea3 OW |
486 | * 1) Use shift to calculate the new vma endpoints. |
487 | * 2) Extend vma to cover both the old and new ranges. This ensures the | |
488 | * arguments passed to subsequent functions are consistent. | |
489 | * 3) Move vma's page tables to the new range. | |
490 | * 4) Free up any cleared pgd range. | |
491 | * 5) Shrink the vma to cover only the new range. | |
1da177e4 | 492 | */ |
b6a2fea3 | 493 | static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) |
1da177e4 LT |
494 | { |
495 | struct mm_struct *mm = vma->vm_mm; | |
b6a2fea3 OW |
496 | unsigned long old_start = vma->vm_start; |
497 | unsigned long old_end = vma->vm_end; | |
498 | unsigned long length = old_end - old_start; | |
499 | unsigned long new_start = old_start - shift; | |
500 | unsigned long new_end = old_end - shift; | |
501 | struct mmu_gather *tlb; | |
1da177e4 | 502 | |
b6a2fea3 | 503 | BUG_ON(new_start > new_end); |
1da177e4 | 504 | |
b6a2fea3 OW |
505 | /* |
506 | * ensure there are no vmas between where we want to go | |
507 | * and where we are | |
508 | */ | |
509 | if (vma != find_vma(mm, new_start)) | |
510 | return -EFAULT; | |
511 | ||
512 | /* | |
513 | * cover the whole range: [new_start, old_end) | |
514 | */ | |
515 | vma_adjust(vma, new_start, old_end, vma->vm_pgoff, NULL); | |
516 | ||
517 | /* | |
518 | * move the page tables downwards, on failure we rely on | |
519 | * process cleanup to remove whatever mess we made. | |
520 | */ | |
521 | if (length != move_page_tables(vma, old_start, | |
522 | vma, new_start, length)) | |
523 | return -ENOMEM; | |
524 | ||
525 | lru_add_drain(); | |
526 | tlb = tlb_gather_mmu(mm, 0); | |
527 | if (new_end > old_start) { | |
528 | /* | |
529 | * when the old and new regions overlap clear from new_end. | |
530 | */ | |
531 | free_pgd_range(&tlb, new_end, old_end, new_end, | |
532 | vma->vm_next ? vma->vm_next->vm_start : 0); | |
533 | } else { | |
534 | /* | |
535 | * otherwise, clean from old_start; this is done to not touch | |
536 | * the address space in [new_end, old_start) some architectures | |
537 | * have constraints on va-space that make this illegal (IA64) - | |
538 | * for the others its just a little faster. | |
539 | */ | |
540 | free_pgd_range(&tlb, old_start, old_end, new_end, | |
541 | vma->vm_next ? vma->vm_next->vm_start : 0); | |
1da177e4 | 542 | } |
b6a2fea3 OW |
543 | tlb_finish_mmu(tlb, new_end, old_end); |
544 | ||
545 | /* | |
546 | * shrink the vma to just the new range. | |
547 | */ | |
548 | vma_adjust(vma, new_start, new_end, vma->vm_pgoff, NULL); | |
549 | ||
550 | return 0; | |
1da177e4 LT |
551 | } |
552 | ||
553 | #define EXTRA_STACK_VM_PAGES 20 /* random */ | |
554 | ||
b6a2fea3 OW |
555 | /* |
556 | * Finalizes the stack vm_area_struct. The flags and permissions are updated, | |
557 | * the stack is optionally relocated, and some extra space is added. | |
558 | */ | |
1da177e4 LT |
559 | int setup_arg_pages(struct linux_binprm *bprm, |
560 | unsigned long stack_top, | |
561 | int executable_stack) | |
562 | { | |
b6a2fea3 OW |
563 | unsigned long ret; |
564 | unsigned long stack_shift; | |
1da177e4 | 565 | struct mm_struct *mm = current->mm; |
b6a2fea3 OW |
566 | struct vm_area_struct *vma = bprm->vma; |
567 | struct vm_area_struct *prev = NULL; | |
568 | unsigned long vm_flags; | |
569 | unsigned long stack_base; | |
1da177e4 LT |
570 | |
571 | #ifdef CONFIG_STACK_GROWSUP | |
1da177e4 LT |
572 | /* Limit stack size to 1GB */ |
573 | stack_base = current->signal->rlim[RLIMIT_STACK].rlim_max; | |
574 | if (stack_base > (1 << 30)) | |
575 | stack_base = 1 << 30; | |
1da177e4 | 576 | |
b6a2fea3 OW |
577 | /* Make sure we didn't let the argument array grow too large. */ |
578 | if (vma->vm_end - vma->vm_start > stack_base) | |
579 | return -ENOMEM; | |
1da177e4 | 580 | |
b6a2fea3 | 581 | stack_base = PAGE_ALIGN(stack_top - stack_base); |
1da177e4 | 582 | |
b6a2fea3 OW |
583 | stack_shift = vma->vm_start - stack_base; |
584 | mm->arg_start = bprm->p - stack_shift; | |
585 | bprm->p = vma->vm_end - stack_shift; | |
1da177e4 | 586 | #else |
b6a2fea3 OW |
587 | stack_top = arch_align_stack(stack_top); |
588 | stack_top = PAGE_ALIGN(stack_top); | |
589 | stack_shift = vma->vm_end - stack_top; | |
590 | ||
591 | bprm->p -= stack_shift; | |
1da177e4 | 592 | mm->arg_start = bprm->p; |
1da177e4 LT |
593 | #endif |
594 | ||
1da177e4 | 595 | if (bprm->loader) |
b6a2fea3 OW |
596 | bprm->loader -= stack_shift; |
597 | bprm->exec -= stack_shift; | |
1da177e4 | 598 | |
1da177e4 | 599 | down_write(&mm->mmap_sem); |
b6a2fea3 OW |
600 | vm_flags = vma->vm_flags; |
601 | ||
602 | /* | |
603 | * Adjust stack execute permissions; explicitly enable for | |
604 | * EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X and leave alone | |
605 | * (arch default) otherwise. | |
606 | */ | |
607 | if (unlikely(executable_stack == EXSTACK_ENABLE_X)) | |
608 | vm_flags |= VM_EXEC; | |
609 | else if (executable_stack == EXSTACK_DISABLE_X) | |
610 | vm_flags &= ~VM_EXEC; | |
611 | vm_flags |= mm->def_flags; | |
612 | ||
613 | ret = mprotect_fixup(vma, &prev, vma->vm_start, vma->vm_end, | |
614 | vm_flags); | |
615 | if (ret) | |
616 | goto out_unlock; | |
617 | BUG_ON(prev != vma); | |
618 | ||
619 | /* Move stack pages down in memory. */ | |
620 | if (stack_shift) { | |
621 | ret = shift_arg_pages(vma, stack_shift); | |
622 | if (ret) { | |
1da177e4 | 623 | up_write(&mm->mmap_sem); |
1da177e4 LT |
624 | return ret; |
625 | } | |
1da177e4 LT |
626 | } |
627 | ||
b6a2fea3 OW |
628 | #ifdef CONFIG_STACK_GROWSUP |
629 | stack_base = vma->vm_end + EXTRA_STACK_VM_PAGES * PAGE_SIZE; | |
630 | #else | |
631 | stack_base = vma->vm_start - EXTRA_STACK_VM_PAGES * PAGE_SIZE; | |
632 | #endif | |
633 | ret = expand_stack(vma, stack_base); | |
634 | if (ret) | |
635 | ret = -EFAULT; | |
636 | ||
637 | out_unlock: | |
1da177e4 | 638 | up_write(&mm->mmap_sem); |
1da177e4 LT |
639 | return 0; |
640 | } | |
1da177e4 LT |
641 | EXPORT_SYMBOL(setup_arg_pages); |
642 | ||
1da177e4 LT |
643 | #endif /* CONFIG_MMU */ |
644 | ||
645 | struct file *open_exec(const char *name) | |
646 | { | |
647 | struct nameidata nd; | |
648 | int err; | |
649 | struct file *file; | |
650 | ||
b500531e | 651 | err = path_lookup_open(AT_FDCWD, name, LOOKUP_FOLLOW, &nd, FMODE_READ|FMODE_EXEC); |
1da177e4 LT |
652 | file = ERR_PTR(err); |
653 | ||
654 | if (!err) { | |
655 | struct inode *inode = nd.dentry->d_inode; | |
656 | file = ERR_PTR(-EACCES); | |
1a159dd2 | 657 | if (S_ISREG(inode->i_mode)) { |
e4543edd | 658 | int err = vfs_permission(&nd, MAY_EXEC); |
1da177e4 LT |
659 | file = ERR_PTR(err); |
660 | if (!err) { | |
abe8be3a AK |
661 | file = nameidata_to_filp(&nd, |
662 | O_RDONLY|O_LARGEFILE); | |
1da177e4 LT |
663 | if (!IS_ERR(file)) { |
664 | err = deny_write_access(file); | |
665 | if (err) { | |
666 | fput(file); | |
667 | file = ERR_PTR(err); | |
668 | } | |
669 | } | |
670 | out: | |
671 | return file; | |
672 | } | |
673 | } | |
834f2a4a | 674 | release_open_intent(&nd); |
1da177e4 LT |
675 | path_release(&nd); |
676 | } | |
677 | goto out; | |
678 | } | |
679 | ||
680 | EXPORT_SYMBOL(open_exec); | |
681 | ||
682 | int kernel_read(struct file *file, unsigned long offset, | |
683 | char *addr, unsigned long count) | |
684 | { | |
685 | mm_segment_t old_fs; | |
686 | loff_t pos = offset; | |
687 | int result; | |
688 | ||
689 | old_fs = get_fs(); | |
690 | set_fs(get_ds()); | |
691 | /* The cast to a user pointer is valid due to the set_fs() */ | |
692 | result = vfs_read(file, (void __user *)addr, count, &pos); | |
693 | set_fs(old_fs); | |
694 | return result; | |
695 | } | |
696 | ||
697 | EXPORT_SYMBOL(kernel_read); | |
698 | ||
699 | static int exec_mmap(struct mm_struct *mm) | |
700 | { | |
701 | struct task_struct *tsk; | |
702 | struct mm_struct * old_mm, *active_mm; | |
703 | ||
704 | /* Notify parent that we're no longer interested in the old VM */ | |
705 | tsk = current; | |
706 | old_mm = current->mm; | |
707 | mm_release(tsk, old_mm); | |
708 | ||
709 | if (old_mm) { | |
710 | /* | |
711 | * Make sure that if there is a core dump in progress | |
712 | * for the old mm, we get out and die instead of going | |
713 | * through with the exec. We must hold mmap_sem around | |
714 | * checking core_waiters and changing tsk->mm. The | |
715 | * core-inducing thread will increment core_waiters for | |
716 | * each thread whose ->mm == old_mm. | |
717 | */ | |
718 | down_read(&old_mm->mmap_sem); | |
719 | if (unlikely(old_mm->core_waiters)) { | |
720 | up_read(&old_mm->mmap_sem); | |
721 | return -EINTR; | |
722 | } | |
723 | } | |
724 | task_lock(tsk); | |
725 | active_mm = tsk->active_mm; | |
726 | tsk->mm = mm; | |
727 | tsk->active_mm = mm; | |
728 | activate_mm(active_mm, mm); | |
729 | task_unlock(tsk); | |
730 | arch_pick_mmap_layout(mm); | |
731 | if (old_mm) { | |
732 | up_read(&old_mm->mmap_sem); | |
7dddb12c | 733 | BUG_ON(active_mm != old_mm); |
1da177e4 LT |
734 | mmput(old_mm); |
735 | return 0; | |
736 | } | |
737 | mmdrop(active_mm); | |
738 | return 0; | |
739 | } | |
740 | ||
741 | /* | |
742 | * This function makes sure the current process has its own signal table, | |
743 | * so that flush_signal_handlers can later reset the handlers without | |
744 | * disturbing other processes. (Other processes might share the signal | |
745 | * table via the CLONE_SIGHAND option to clone().) | |
746 | */ | |
858119e1 | 747 | static int de_thread(struct task_struct *tsk) |
1da177e4 LT |
748 | { |
749 | struct signal_struct *sig = tsk->signal; | |
b2c903b8 | 750 | struct sighand_struct *oldsighand = tsk->sighand; |
1da177e4 | 751 | spinlock_t *lock = &oldsighand->siglock; |
329f7dba | 752 | struct task_struct *leader = NULL; |
1da177e4 LT |
753 | int count; |
754 | ||
aafe6c2a | 755 | if (thread_group_empty(tsk)) |
1da177e4 LT |
756 | goto no_thread_group; |
757 | ||
758 | /* | |
759 | * Kill all other threads in the thread group. | |
760 | * We must hold tasklist_lock to call zap_other_threads. | |
761 | */ | |
762 | read_lock(&tasklist_lock); | |
763 | spin_lock_irq(lock); | |
ed5d2cac | 764 | if (signal_group_exit(sig)) { |
1da177e4 LT |
765 | /* |
766 | * Another group action in progress, just | |
767 | * return so that the signal is processed. | |
768 | */ | |
769 | spin_unlock_irq(lock); | |
770 | read_unlock(&tasklist_lock); | |
1da177e4 LT |
771 | return -EAGAIN; |
772 | } | |
1434261c ON |
773 | |
774 | /* | |
775 | * child_reaper ignores SIGKILL, change it now. | |
776 | * Reparenting needs write_lock on tasklist_lock, | |
777 | * so it is safe to do it under read_lock. | |
778 | */ | |
88f21d81 | 779 | if (unlikely(tsk->group_leader == task_child_reaper(tsk))) |
2894d650 | 780 | task_active_pid_ns(tsk)->child_reaper = tsk; |
1434261c | 781 | |
ed5d2cac | 782 | sig->group_exit_task = tsk; |
aafe6c2a | 783 | zap_other_threads(tsk); |
1da177e4 LT |
784 | read_unlock(&tasklist_lock); |
785 | ||
fea9d175 ON |
786 | /* Account for the thread group leader hanging around: */ |
787 | count = thread_group_leader(tsk) ? 1 : 2; | |
6db840fa | 788 | sig->notify_count = count; |
1da177e4 | 789 | while (atomic_read(&sig->count) > count) { |
1da177e4 LT |
790 | __set_current_state(TASK_UNINTERRUPTIBLE); |
791 | spin_unlock_irq(lock); | |
792 | schedule(); | |
793 | spin_lock_irq(lock); | |
794 | } | |
1da177e4 LT |
795 | spin_unlock_irq(lock); |
796 | ||
797 | /* | |
798 | * At this point all other threads have exited, all we have to | |
799 | * do is to wait for the thread group leader to become inactive, | |
800 | * and to assume its PID: | |
801 | */ | |
aafe6c2a | 802 | if (!thread_group_leader(tsk)) { |
aafe6c2a | 803 | leader = tsk->group_leader; |
6db840fa ON |
804 | |
805 | sig->notify_count = -1; | |
806 | for (;;) { | |
807 | write_lock_irq(&tasklist_lock); | |
808 | if (likely(leader->exit_state)) | |
809 | break; | |
810 | __set_current_state(TASK_UNINTERRUPTIBLE); | |
811 | write_unlock_irq(&tasklist_lock); | |
812 | schedule(); | |
813 | } | |
1da177e4 | 814 | |
f5e90281 RM |
815 | /* |
816 | * The only record we have of the real-time age of a | |
817 | * process, regardless of execs it's done, is start_time. | |
818 | * All the past CPU time is accumulated in signal_struct | |
819 | * from sister threads now dead. But in this non-leader | |
820 | * exec, nothing survives from the original leader thread, | |
821 | * whose birth marks the true age of this process now. | |
822 | * When we take on its identity by switching to its PID, we | |
823 | * also take its birthdate (always earlier than our own). | |
824 | */ | |
aafe6c2a | 825 | tsk->start_time = leader->start_time; |
f5e90281 | 826 | |
bac0abd6 PE |
827 | BUG_ON(!same_thread_group(leader, tsk)); |
828 | BUG_ON(has_group_leader_pid(tsk)); | |
1da177e4 LT |
829 | /* |
830 | * An exec() starts a new thread group with the | |
831 | * TGID of the previous thread group. Rehash the | |
832 | * two threads with a switched PID, and release | |
833 | * the former thread group leader: | |
834 | */ | |
d73d6529 EB |
835 | |
836 | /* Become a process group leader with the old leader's pid. | |
c18258c6 EB |
837 | * The old leader becomes a thread of the this thread group. |
838 | * Note: The old leader also uses this pid until release_task | |
d73d6529 EB |
839 | * is called. Odd but simple and correct. |
840 | */ | |
aafe6c2a EB |
841 | detach_pid(tsk, PIDTYPE_PID); |
842 | tsk->pid = leader->pid; | |
3743ca05 | 843 | attach_pid(tsk, PIDTYPE_PID, task_pid(leader)); |
aafe6c2a EB |
844 | transfer_pid(leader, tsk, PIDTYPE_PGID); |
845 | transfer_pid(leader, tsk, PIDTYPE_SID); | |
846 | list_replace_rcu(&leader->tasks, &tsk->tasks); | |
1da177e4 | 847 | |
aafe6c2a EB |
848 | tsk->group_leader = tsk; |
849 | leader->group_leader = tsk; | |
de12a787 | 850 | |
aafe6c2a | 851 | tsk->exit_signal = SIGCHLD; |
962b564c ON |
852 | |
853 | BUG_ON(leader->exit_state != EXIT_ZOMBIE); | |
854 | leader->exit_state = EXIT_DEAD; | |
1da177e4 LT |
855 | |
856 | write_unlock_irq(&tasklist_lock); | |
ed5d2cac | 857 | } |
1da177e4 | 858 | |
6db840fa ON |
859 | sig->group_exit_task = NULL; |
860 | sig->notify_count = 0; | |
1da177e4 LT |
861 | |
862 | no_thread_group: | |
1da177e4 | 863 | exit_itimers(sig); |
329f7dba ON |
864 | if (leader) |
865 | release_task(leader); | |
866 | ||
b2c903b8 ON |
867 | if (atomic_read(&oldsighand->count) != 1) { |
868 | struct sighand_struct *newsighand; | |
1da177e4 | 869 | /* |
b2c903b8 ON |
870 | * This ->sighand is shared with the CLONE_SIGHAND |
871 | * but not CLONE_THREAD task, switch to the new one. | |
1da177e4 | 872 | */ |
b2c903b8 ON |
873 | newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL); |
874 | if (!newsighand) | |
875 | return -ENOMEM; | |
876 | ||
1da177e4 LT |
877 | atomic_set(&newsighand->count, 1); |
878 | memcpy(newsighand->action, oldsighand->action, | |
879 | sizeof(newsighand->action)); | |
880 | ||
881 | write_lock_irq(&tasklist_lock); | |
882 | spin_lock(&oldsighand->siglock); | |
aafe6c2a | 883 | rcu_assign_pointer(tsk->sighand, newsighand); |
1da177e4 LT |
884 | spin_unlock(&oldsighand->siglock); |
885 | write_unlock_irq(&tasklist_lock); | |
886 | ||
fba2afaa | 887 | __cleanup_sighand(oldsighand); |
1da177e4 LT |
888 | } |
889 | ||
aafe6c2a | 890 | BUG_ON(!thread_group_leader(tsk)); |
1da177e4 LT |
891 | return 0; |
892 | } | |
0840a90d | 893 | |
1da177e4 LT |
894 | /* |
895 | * These functions flushes out all traces of the currently running executable | |
896 | * so that a new one can be started | |
897 | */ | |
858119e1 | 898 | static void flush_old_files(struct files_struct * files) |
1da177e4 LT |
899 | { |
900 | long j = -1; | |
badf1662 | 901 | struct fdtable *fdt; |
1da177e4 LT |
902 | |
903 | spin_lock(&files->file_lock); | |
904 | for (;;) { | |
905 | unsigned long set, i; | |
906 | ||
907 | j++; | |
908 | i = j * __NFDBITS; | |
badf1662 | 909 | fdt = files_fdtable(files); |
bbea9f69 | 910 | if (i >= fdt->max_fds) |
1da177e4 | 911 | break; |
badf1662 | 912 | set = fdt->close_on_exec->fds_bits[j]; |
1da177e4 LT |
913 | if (!set) |
914 | continue; | |
badf1662 | 915 | fdt->close_on_exec->fds_bits[j] = 0; |
1da177e4 LT |
916 | spin_unlock(&files->file_lock); |
917 | for ( ; set ; i++,set >>= 1) { | |
918 | if (set & 1) { | |
919 | sys_close(i); | |
920 | } | |
921 | } | |
922 | spin_lock(&files->file_lock); | |
923 | ||
924 | } | |
925 | spin_unlock(&files->file_lock); | |
926 | } | |
927 | ||
59714d65 | 928 | char *get_task_comm(char *buf, struct task_struct *tsk) |
1da177e4 LT |
929 | { |
930 | /* buf must be at least sizeof(tsk->comm) in size */ | |
931 | task_lock(tsk); | |
932 | strncpy(buf, tsk->comm, sizeof(tsk->comm)); | |
933 | task_unlock(tsk); | |
59714d65 | 934 | return buf; |
1da177e4 LT |
935 | } |
936 | ||
937 | void set_task_comm(struct task_struct *tsk, char *buf) | |
938 | { | |
939 | task_lock(tsk); | |
940 | strlcpy(tsk->comm, buf, sizeof(tsk->comm)); | |
941 | task_unlock(tsk); | |
942 | } | |
943 | ||
944 | int flush_old_exec(struct linux_binprm * bprm) | |
945 | { | |
946 | char * name; | |
947 | int i, ch, retval; | |
948 | struct files_struct *files; | |
949 | char tcomm[sizeof(current->comm)]; | |
950 | ||
951 | /* | |
952 | * Make sure we have a private signal table and that | |
953 | * we are unassociated from the previous thread group. | |
954 | */ | |
955 | retval = de_thread(current); | |
956 | if (retval) | |
957 | goto out; | |
958 | ||
959 | /* | |
960 | * Make sure we have private file handles. Ask the | |
961 | * fork helper to do the work for us and the exit | |
962 | * helper to do the cleanup of the old one. | |
963 | */ | |
964 | files = current->files; /* refcounted so safe to hold */ | |
965 | retval = unshare_files(); | |
966 | if (retval) | |
967 | goto out; | |
968 | /* | |
969 | * Release all of the old mmap stuff | |
970 | */ | |
971 | retval = exec_mmap(bprm->mm); | |
972 | if (retval) | |
973 | goto mmap_failed; | |
974 | ||
975 | bprm->mm = NULL; /* We're using it now */ | |
976 | ||
977 | /* This is the point of no return */ | |
1da177e4 LT |
978 | put_files_struct(files); |
979 | ||
980 | current->sas_ss_sp = current->sas_ss_size = 0; | |
981 | ||
982 | if (current->euid == current->uid && current->egid == current->gid) | |
6c5d5238 | 983 | set_dumpable(current->mm, 1); |
d6e71144 | 984 | else |
6c5d5238 | 985 | set_dumpable(current->mm, suid_dumpable); |
d6e71144 | 986 | |
1da177e4 | 987 | name = bprm->filename; |
36772092 PBG |
988 | |
989 | /* Copies the binary name from after last slash */ | |
1da177e4 LT |
990 | for (i=0; (ch = *(name++)) != '\0';) { |
991 | if (ch == '/') | |
36772092 | 992 | i = 0; /* overwrite what we wrote */ |
1da177e4 LT |
993 | else |
994 | if (i < (sizeof(tcomm) - 1)) | |
995 | tcomm[i++] = ch; | |
996 | } | |
997 | tcomm[i] = '\0'; | |
998 | set_task_comm(current, tcomm); | |
999 | ||
1000 | current->flags &= ~PF_RANDOMIZE; | |
1001 | flush_thread(); | |
1002 | ||
0551fbd2 BH |
1003 | /* Set the new mm task size. We have to do that late because it may |
1004 | * depend on TIF_32BIT which is only updated in flush_thread() on | |
1005 | * some architectures like powerpc | |
1006 | */ | |
1007 | current->mm->task_size = TASK_SIZE; | |
1008 | ||
d2d56c5f MH |
1009 | if (bprm->e_uid != current->euid || bprm->e_gid != current->egid) { |
1010 | suid_keys(current); | |
1011 | set_dumpable(current->mm, suid_dumpable); | |
1012 | current->pdeath_signal = 0; | |
1013 | } else if (file_permission(bprm->file, MAY_READ) || | |
1014 | (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP)) { | |
1da177e4 | 1015 | suid_keys(current); |
6c5d5238 | 1016 | set_dumpable(current->mm, suid_dumpable); |
1da177e4 LT |
1017 | } |
1018 | ||
1019 | /* An exec changes our domain. We are no longer part of the thread | |
1020 | group */ | |
1021 | ||
1022 | current->self_exec_id++; | |
1023 | ||
1024 | flush_signal_handlers(current, 0); | |
1025 | flush_old_files(current->files); | |
1026 | ||
1027 | return 0; | |
1028 | ||
1029 | mmap_failed: | |
3b9b8ab6 | 1030 | reset_files_struct(current, files); |
1da177e4 LT |
1031 | out: |
1032 | return retval; | |
1033 | } | |
1034 | ||
1035 | EXPORT_SYMBOL(flush_old_exec); | |
1036 | ||
1037 | /* | |
1038 | * Fill the binprm structure from the inode. | |
1039 | * Check permissions, then read the first 128 (BINPRM_BUF_SIZE) bytes | |
1040 | */ | |
1041 | int prepare_binprm(struct linux_binprm *bprm) | |
1042 | { | |
1043 | int mode; | |
0f7fc9e4 | 1044 | struct inode * inode = bprm->file->f_path.dentry->d_inode; |
1da177e4 LT |
1045 | int retval; |
1046 | ||
1047 | mode = inode->i_mode; | |
1da177e4 LT |
1048 | if (bprm->file->f_op == NULL) |
1049 | return -EACCES; | |
1050 | ||
1051 | bprm->e_uid = current->euid; | |
1052 | bprm->e_gid = current->egid; | |
1053 | ||
0f7fc9e4 | 1054 | if(!(bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)) { |
1da177e4 LT |
1055 | /* Set-uid? */ |
1056 | if (mode & S_ISUID) { | |
1057 | current->personality &= ~PER_CLEAR_ON_SETID; | |
1058 | bprm->e_uid = inode->i_uid; | |
1059 | } | |
1060 | ||
1061 | /* Set-gid? */ | |
1062 | /* | |
1063 | * If setgid is set but no group execute bit then this | |
1064 | * is a candidate for mandatory locking, not a setgid | |
1065 | * executable. | |
1066 | */ | |
1067 | if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { | |
1068 | current->personality &= ~PER_CLEAR_ON_SETID; | |
1069 | bprm->e_gid = inode->i_gid; | |
1070 | } | |
1071 | } | |
1072 | ||
1073 | /* fill in binprm security blob */ | |
1074 | retval = security_bprm_set(bprm); | |
1075 | if (retval) | |
1076 | return retval; | |
1077 | ||
1078 | memset(bprm->buf,0,BINPRM_BUF_SIZE); | |
1079 | return kernel_read(bprm->file,0,bprm->buf,BINPRM_BUF_SIZE); | |
1080 | } | |
1081 | ||
1082 | EXPORT_SYMBOL(prepare_binprm); | |
1083 | ||
858119e1 | 1084 | static int unsafe_exec(struct task_struct *p) |
1da177e4 LT |
1085 | { |
1086 | int unsafe = 0; | |
1087 | if (p->ptrace & PT_PTRACED) { | |
1088 | if (p->ptrace & PT_PTRACE_CAP) | |
1089 | unsafe |= LSM_UNSAFE_PTRACE_CAP; | |
1090 | else | |
1091 | unsafe |= LSM_UNSAFE_PTRACE; | |
1092 | } | |
1093 | if (atomic_read(&p->fs->count) > 1 || | |
1094 | atomic_read(&p->files->count) > 1 || | |
1095 | atomic_read(&p->sighand->count) > 1) | |
1096 | unsafe |= LSM_UNSAFE_SHARE; | |
1097 | ||
1098 | return unsafe; | |
1099 | } | |
1100 | ||
1101 | void compute_creds(struct linux_binprm *bprm) | |
1102 | { | |
1103 | int unsafe; | |
1104 | ||
d2d56c5f | 1105 | if (bprm->e_uid != current->uid) { |
1da177e4 | 1106 | suid_keys(current); |
d2d56c5f MH |
1107 | current->pdeath_signal = 0; |
1108 | } | |
1da177e4 LT |
1109 | exec_keys(current); |
1110 | ||
1111 | task_lock(current); | |
1112 | unsafe = unsafe_exec(current); | |
1113 | security_bprm_apply_creds(bprm, unsafe); | |
1114 | task_unlock(current); | |
1115 | security_bprm_post_apply_creds(bprm); | |
1116 | } | |
1da177e4 LT |
1117 | EXPORT_SYMBOL(compute_creds); |
1118 | ||
4fc75ff4 NP |
1119 | /* |
1120 | * Arguments are '\0' separated strings found at the location bprm->p | |
1121 | * points to; chop off the first by relocating brpm->p to right after | |
1122 | * the first '\0' encountered. | |
1123 | */ | |
b6a2fea3 | 1124 | int remove_arg_zero(struct linux_binprm *bprm) |
1da177e4 | 1125 | { |
b6a2fea3 OW |
1126 | int ret = 0; |
1127 | unsigned long offset; | |
1128 | char *kaddr; | |
1129 | struct page *page; | |
4fc75ff4 | 1130 | |
b6a2fea3 OW |
1131 | if (!bprm->argc) |
1132 | return 0; | |
1da177e4 | 1133 | |
b6a2fea3 OW |
1134 | do { |
1135 | offset = bprm->p & ~PAGE_MASK; | |
1136 | page = get_arg_page(bprm, bprm->p, 0); | |
1137 | if (!page) { | |
1138 | ret = -EFAULT; | |
1139 | goto out; | |
1140 | } | |
1141 | kaddr = kmap_atomic(page, KM_USER0); | |
4fc75ff4 | 1142 | |
b6a2fea3 OW |
1143 | for (; offset < PAGE_SIZE && kaddr[offset]; |
1144 | offset++, bprm->p++) | |
1145 | ; | |
4fc75ff4 | 1146 | |
b6a2fea3 OW |
1147 | kunmap_atomic(kaddr, KM_USER0); |
1148 | put_arg_page(page); | |
4fc75ff4 | 1149 | |
b6a2fea3 OW |
1150 | if (offset == PAGE_SIZE) |
1151 | free_arg_page(bprm, (bprm->p >> PAGE_SHIFT) - 1); | |
1152 | } while (offset == PAGE_SIZE); | |
4fc75ff4 | 1153 | |
b6a2fea3 OW |
1154 | bprm->p++; |
1155 | bprm->argc--; | |
1156 | ret = 0; | |
4fc75ff4 | 1157 | |
b6a2fea3 OW |
1158 | out: |
1159 | return ret; | |
1da177e4 | 1160 | } |
1da177e4 LT |
1161 | EXPORT_SYMBOL(remove_arg_zero); |
1162 | ||
1163 | /* | |
1164 | * cycle the list of binary formats handler, until one recognizes the image | |
1165 | */ | |
1166 | int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs) | |
1167 | { | |
1168 | int try,retval; | |
1169 | struct linux_binfmt *fmt; | |
7fa30315 | 1170 | #if defined(__alpha__) && defined(CONFIG_ARCH_SUPPORTS_AOUT) |
1da177e4 LT |
1171 | /* handle /sbin/loader.. */ |
1172 | { | |
1173 | struct exec * eh = (struct exec *) bprm->buf; | |
1174 | ||
1175 | if (!bprm->loader && eh->fh.f_magic == 0x183 && | |
1176 | (eh->fh.f_flags & 0x3000) == 0x3000) | |
1177 | { | |
1178 | struct file * file; | |
1179 | unsigned long loader; | |
1180 | ||
1181 | allow_write_access(bprm->file); | |
1182 | fput(bprm->file); | |
1183 | bprm->file = NULL; | |
1184 | ||
b6a2fea3 | 1185 | loader = bprm->vma->vm_end - sizeof(void *); |
1da177e4 LT |
1186 | |
1187 | file = open_exec("/sbin/loader"); | |
1188 | retval = PTR_ERR(file); | |
1189 | if (IS_ERR(file)) | |
1190 | return retval; | |
1191 | ||
1192 | /* Remember if the application is TASO. */ | |
1193 | bprm->sh_bang = eh->ah.entry < 0x100000000UL; | |
1194 | ||
1195 | bprm->file = file; | |
1196 | bprm->loader = loader; | |
1197 | retval = prepare_binprm(bprm); | |
1198 | if (retval<0) | |
1199 | return retval; | |
1200 | /* should call search_binary_handler recursively here, | |
1201 | but it does not matter */ | |
1202 | } | |
1203 | } | |
1204 | #endif | |
1205 | retval = security_bprm_check(bprm); | |
1206 | if (retval) | |
1207 | return retval; | |
1208 | ||
1209 | /* kernel module loader fixup */ | |
1210 | /* so we don't try to load run modprobe in kernel space. */ | |
1211 | set_fs(USER_DS); | |
473ae30b AV |
1212 | |
1213 | retval = audit_bprm(bprm); | |
1214 | if (retval) | |
1215 | return retval; | |
1216 | ||
1da177e4 LT |
1217 | retval = -ENOENT; |
1218 | for (try=0; try<2; try++) { | |
1219 | read_lock(&binfmt_lock); | |
e4dc1b14 | 1220 | list_for_each_entry(fmt, &formats, lh) { |
1da177e4 LT |
1221 | int (*fn)(struct linux_binprm *, struct pt_regs *) = fmt->load_binary; |
1222 | if (!fn) | |
1223 | continue; | |
1224 | if (!try_module_get(fmt->module)) | |
1225 | continue; | |
1226 | read_unlock(&binfmt_lock); | |
1227 | retval = fn(bprm, regs); | |
1228 | if (retval >= 0) { | |
1229 | put_binfmt(fmt); | |
1230 | allow_write_access(bprm->file); | |
1231 | if (bprm->file) | |
1232 | fput(bprm->file); | |
1233 | bprm->file = NULL; | |
1234 | current->did_exec = 1; | |
9f46080c | 1235 | proc_exec_connector(current); |
1da177e4 LT |
1236 | return retval; |
1237 | } | |
1238 | read_lock(&binfmt_lock); | |
1239 | put_binfmt(fmt); | |
1240 | if (retval != -ENOEXEC || bprm->mm == NULL) | |
1241 | break; | |
1242 | if (!bprm->file) { | |
1243 | read_unlock(&binfmt_lock); | |
1244 | return retval; | |
1245 | } | |
1246 | } | |
1247 | read_unlock(&binfmt_lock); | |
1248 | if (retval != -ENOEXEC || bprm->mm == NULL) { | |
1249 | break; | |
1250 | #ifdef CONFIG_KMOD | |
1251 | }else{ | |
1252 | #define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e)) | |
1253 | if (printable(bprm->buf[0]) && | |
1254 | printable(bprm->buf[1]) && | |
1255 | printable(bprm->buf[2]) && | |
1256 | printable(bprm->buf[3])) | |
1257 | break; /* -ENOEXEC */ | |
1258 | request_module("binfmt-%04x", *(unsigned short *)(&bprm->buf[2])); | |
1259 | #endif | |
1260 | } | |
1261 | } | |
1262 | return retval; | |
1263 | } | |
1264 | ||
1265 | EXPORT_SYMBOL(search_binary_handler); | |
1266 | ||
1267 | /* | |
1268 | * sys_execve() executes a new program. | |
1269 | */ | |
1270 | int do_execve(char * filename, | |
1271 | char __user *__user *argv, | |
1272 | char __user *__user *envp, | |
1273 | struct pt_regs * regs) | |
1274 | { | |
1275 | struct linux_binprm *bprm; | |
1276 | struct file *file; | |
bdf4c48a | 1277 | unsigned long env_p; |
1da177e4 | 1278 | int retval; |
1da177e4 LT |
1279 | |
1280 | retval = -ENOMEM; | |
11b0b5ab | 1281 | bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); |
1da177e4 LT |
1282 | if (!bprm) |
1283 | goto out_ret; | |
1da177e4 LT |
1284 | |
1285 | file = open_exec(filename); | |
1286 | retval = PTR_ERR(file); | |
1287 | if (IS_ERR(file)) | |
1288 | goto out_kfree; | |
1289 | ||
1290 | sched_exec(); | |
1291 | ||
1da177e4 LT |
1292 | bprm->file = file; |
1293 | bprm->filename = filename; | |
1294 | bprm->interp = filename; | |
1da177e4 | 1295 | |
b6a2fea3 OW |
1296 | retval = bprm_mm_init(bprm); |
1297 | if (retval) | |
1298 | goto out_file; | |
1da177e4 | 1299 | |
b6a2fea3 | 1300 | bprm->argc = count(argv, MAX_ARG_STRINGS); |
1da177e4 LT |
1301 | if ((retval = bprm->argc) < 0) |
1302 | goto out_mm; | |
1303 | ||
b6a2fea3 | 1304 | bprm->envc = count(envp, MAX_ARG_STRINGS); |
1da177e4 LT |
1305 | if ((retval = bprm->envc) < 0) |
1306 | goto out_mm; | |
1307 | ||
1308 | retval = security_bprm_alloc(bprm); | |
1309 | if (retval) | |
1310 | goto out; | |
1311 | ||
1312 | retval = prepare_binprm(bprm); | |
1313 | if (retval < 0) | |
1314 | goto out; | |
1315 | ||
1316 | retval = copy_strings_kernel(1, &bprm->filename, bprm); | |
1317 | if (retval < 0) | |
1318 | goto out; | |
1319 | ||
1320 | bprm->exec = bprm->p; | |
1321 | retval = copy_strings(bprm->envc, envp, bprm); | |
1322 | if (retval < 0) | |
1323 | goto out; | |
1324 | ||
bdf4c48a | 1325 | env_p = bprm->p; |
1da177e4 LT |
1326 | retval = copy_strings(bprm->argc, argv, bprm); |
1327 | if (retval < 0) | |
1328 | goto out; | |
bdf4c48a | 1329 | bprm->argv_len = env_p - bprm->p; |
1da177e4 LT |
1330 | |
1331 | retval = search_binary_handler(bprm,regs); | |
1332 | if (retval >= 0) { | |
1da177e4 | 1333 | /* execve success */ |
b6a2fea3 | 1334 | free_arg_pages(bprm); |
1da177e4 LT |
1335 | security_bprm_free(bprm); |
1336 | acct_update_integrals(current); | |
1da177e4 LT |
1337 | kfree(bprm); |
1338 | return retval; | |
1339 | } | |
1340 | ||
1341 | out: | |
b6a2fea3 | 1342 | free_arg_pages(bprm); |
1da177e4 LT |
1343 | if (bprm->security) |
1344 | security_bprm_free(bprm); | |
1345 | ||
1346 | out_mm: | |
1347 | if (bprm->mm) | |
b6a2fea3 | 1348 | mmput (bprm->mm); |
1da177e4 LT |
1349 | |
1350 | out_file: | |
1351 | if (bprm->file) { | |
1352 | allow_write_access(bprm->file); | |
1353 | fput(bprm->file); | |
1354 | } | |
1da177e4 LT |
1355 | out_kfree: |
1356 | kfree(bprm); | |
1357 | ||
1358 | out_ret: | |
1359 | return retval; | |
1360 | } | |
1361 | ||
1362 | int set_binfmt(struct linux_binfmt *new) | |
1363 | { | |
1364 | struct linux_binfmt *old = current->binfmt; | |
1365 | ||
1366 | if (new) { | |
1367 | if (!try_module_get(new->module)) | |
1368 | return -1; | |
1369 | } | |
1370 | current->binfmt = new; | |
1371 | if (old) | |
1372 | module_put(old->module); | |
1373 | return 0; | |
1374 | } | |
1375 | ||
1376 | EXPORT_SYMBOL(set_binfmt); | |
1377 | ||
1da177e4 LT |
1378 | /* format_corename will inspect the pattern parameter, and output a |
1379 | * name into corename, which must have space for at least | |
1380 | * CORENAME_MAX_SIZE bytes plus one byte for the zero terminator. | |
1381 | */ | |
c4bbafda | 1382 | static int format_corename(char *corename, const char *pattern, long signr) |
1da177e4 LT |
1383 | { |
1384 | const char *pat_ptr = pattern; | |
1385 | char *out_ptr = corename; | |
1386 | char *const out_end = corename + CORENAME_MAX_SIZE; | |
1387 | int rc; | |
1388 | int pid_in_pattern = 0; | |
c4bbafda AC |
1389 | int ispipe = 0; |
1390 | ||
1391 | if (*pattern == '|') | |
1392 | ispipe = 1; | |
1da177e4 LT |
1393 | |
1394 | /* Repeat as long as we have more pattern to process and more output | |
1395 | space */ | |
1396 | while (*pat_ptr) { | |
1397 | if (*pat_ptr != '%') { | |
1398 | if (out_ptr == out_end) | |
1399 | goto out; | |
1400 | *out_ptr++ = *pat_ptr++; | |
1401 | } else { | |
1402 | switch (*++pat_ptr) { | |
1403 | case 0: | |
1404 | goto out; | |
1405 | /* Double percent, output one percent */ | |
1406 | case '%': | |
1407 | if (out_ptr == out_end) | |
1408 | goto out; | |
1409 | *out_ptr++ = '%'; | |
1410 | break; | |
1411 | /* pid */ | |
1412 | case 'p': | |
1413 | pid_in_pattern = 1; | |
1414 | rc = snprintf(out_ptr, out_end - out_ptr, | |
b488893a | 1415 | "%d", task_tgid_vnr(current)); |
1da177e4 LT |
1416 | if (rc > out_end - out_ptr) |
1417 | goto out; | |
1418 | out_ptr += rc; | |
1419 | break; | |
1420 | /* uid */ | |
1421 | case 'u': | |
1422 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1423 | "%d", current->uid); | |
1424 | if (rc > out_end - out_ptr) | |
1425 | goto out; | |
1426 | out_ptr += rc; | |
1427 | break; | |
1428 | /* gid */ | |
1429 | case 'g': | |
1430 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1431 | "%d", current->gid); | |
1432 | if (rc > out_end - out_ptr) | |
1433 | goto out; | |
1434 | out_ptr += rc; | |
1435 | break; | |
1436 | /* signal that caused the coredump */ | |
1437 | case 's': | |
1438 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1439 | "%ld", signr); | |
1440 | if (rc > out_end - out_ptr) | |
1441 | goto out; | |
1442 | out_ptr += rc; | |
1443 | break; | |
1444 | /* UNIX time of coredump */ | |
1445 | case 't': { | |
1446 | struct timeval tv; | |
1447 | do_gettimeofday(&tv); | |
1448 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1449 | "%lu", tv.tv_sec); | |
1450 | if (rc > out_end - out_ptr) | |
1451 | goto out; | |
1452 | out_ptr += rc; | |
1453 | break; | |
1454 | } | |
1455 | /* hostname */ | |
1456 | case 'h': | |
1457 | down_read(&uts_sem); | |
1458 | rc = snprintf(out_ptr, out_end - out_ptr, | |
e9ff3990 | 1459 | "%s", utsname()->nodename); |
1da177e4 LT |
1460 | up_read(&uts_sem); |
1461 | if (rc > out_end - out_ptr) | |
1462 | goto out; | |
1463 | out_ptr += rc; | |
1464 | break; | |
1465 | /* executable */ | |
1466 | case 'e': | |
1467 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1468 | "%s", current->comm); | |
1469 | if (rc > out_end - out_ptr) | |
1470 | goto out; | |
1471 | out_ptr += rc; | |
1472 | break; | |
74aadce9 NH |
1473 | /* core limit size */ |
1474 | case 'c': | |
1475 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1476 | "%lu", current->signal->rlim[RLIMIT_CORE].rlim_cur); | |
1477 | if (rc > out_end - out_ptr) | |
1478 | goto out; | |
1479 | out_ptr += rc; | |
1480 | break; | |
1da177e4 LT |
1481 | default: |
1482 | break; | |
1483 | } | |
1484 | ++pat_ptr; | |
1485 | } | |
1486 | } | |
1487 | /* Backward compatibility with core_uses_pid: | |
1488 | * | |
1489 | * If core_pattern does not include a %p (as is the default) | |
1490 | * and core_uses_pid is set, then .%pid will be appended to | |
c4bbafda AC |
1491 | * the filename. Do not do this for piped commands. */ |
1492 | if (!ispipe && !pid_in_pattern | |
1da177e4 LT |
1493 | && (core_uses_pid || atomic_read(¤t->mm->mm_users) != 1)) { |
1494 | rc = snprintf(out_ptr, out_end - out_ptr, | |
b488893a | 1495 | ".%d", task_tgid_vnr(current)); |
1da177e4 LT |
1496 | if (rc > out_end - out_ptr) |
1497 | goto out; | |
1498 | out_ptr += rc; | |
1499 | } | |
c4bbafda | 1500 | out: |
1da177e4 | 1501 | *out_ptr = 0; |
c4bbafda | 1502 | return ispipe; |
1da177e4 LT |
1503 | } |
1504 | ||
d5f70c00 | 1505 | static void zap_process(struct task_struct *start) |
aceecc04 ON |
1506 | { |
1507 | struct task_struct *t; | |
281de339 | 1508 | |
d5f70c00 ON |
1509 | start->signal->flags = SIGNAL_GROUP_EXIT; |
1510 | start->signal->group_stop_count = 0; | |
aceecc04 ON |
1511 | |
1512 | t = start; | |
1513 | do { | |
1514 | if (t != current && t->mm) { | |
1515 | t->mm->core_waiters++; | |
281de339 ON |
1516 | sigaddset(&t->pending.signal, SIGKILL); |
1517 | signal_wake_up(t, 1); | |
aceecc04 ON |
1518 | } |
1519 | } while ((t = next_thread(t)) != start); | |
1520 | } | |
1521 | ||
dcf560c5 ON |
1522 | static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm, |
1523 | int exit_code) | |
1da177e4 LT |
1524 | { |
1525 | struct task_struct *g, *p; | |
5debfa6d | 1526 | unsigned long flags; |
dcf560c5 ON |
1527 | int err = -EAGAIN; |
1528 | ||
1529 | spin_lock_irq(&tsk->sighand->siglock); | |
ed5d2cac | 1530 | if (!signal_group_exit(tsk->signal)) { |
dcf560c5 | 1531 | tsk->signal->group_exit_code = exit_code; |
5debfa6d | 1532 | zap_process(tsk); |
dcf560c5 | 1533 | err = 0; |
1da177e4 | 1534 | } |
dcf560c5 ON |
1535 | spin_unlock_irq(&tsk->sighand->siglock); |
1536 | if (err) | |
1537 | return err; | |
1da177e4 | 1538 | |
5debfa6d ON |
1539 | if (atomic_read(&mm->mm_users) == mm->core_waiters + 1) |
1540 | goto done; | |
1541 | ||
7b1c6154 | 1542 | rcu_read_lock(); |
aceecc04 | 1543 | for_each_process(g) { |
5debfa6d ON |
1544 | if (g == tsk->group_leader) |
1545 | continue; | |
1546 | ||
aceecc04 ON |
1547 | p = g; |
1548 | do { | |
1549 | if (p->mm) { | |
5debfa6d ON |
1550 | if (p->mm == mm) { |
1551 | /* | |
1552 | * p->sighand can't disappear, but | |
1553 | * may be changed by de_thread() | |
1554 | */ | |
1555 | lock_task_sighand(p, &flags); | |
d5f70c00 | 1556 | zap_process(p); |
5debfa6d ON |
1557 | unlock_task_sighand(p, &flags); |
1558 | } | |
aceecc04 ON |
1559 | break; |
1560 | } | |
1561 | } while ((p = next_thread(p)) != g); | |
1562 | } | |
7b1c6154 | 1563 | rcu_read_unlock(); |
5debfa6d | 1564 | done: |
dcf560c5 | 1565 | return mm->core_waiters; |
1da177e4 LT |
1566 | } |
1567 | ||
dcf560c5 | 1568 | static int coredump_wait(int exit_code) |
1da177e4 | 1569 | { |
dcf560c5 ON |
1570 | struct task_struct *tsk = current; |
1571 | struct mm_struct *mm = tsk->mm; | |
1572 | struct completion startup_done; | |
1573 | struct completion *vfork_done; | |
2384f55f | 1574 | int core_waiters; |
1da177e4 | 1575 | |
dcf560c5 ON |
1576 | init_completion(&mm->core_done); |
1577 | init_completion(&startup_done); | |
1da177e4 LT |
1578 | mm->core_startup_done = &startup_done; |
1579 | ||
dcf560c5 | 1580 | core_waiters = zap_threads(tsk, mm, exit_code); |
2384f55f ON |
1581 | up_write(&mm->mmap_sem); |
1582 | ||
dcf560c5 ON |
1583 | if (unlikely(core_waiters < 0)) |
1584 | goto fail; | |
1585 | ||
1586 | /* | |
1587 | * Make sure nobody is waiting for us to release the VM, | |
1588 | * otherwise we can deadlock when we wait on each other | |
1589 | */ | |
1590 | vfork_done = tsk->vfork_done; | |
1591 | if (vfork_done) { | |
1592 | tsk->vfork_done = NULL; | |
1593 | complete(vfork_done); | |
1594 | } | |
1595 | ||
2384f55f | 1596 | if (core_waiters) |
1da177e4 | 1597 | wait_for_completion(&startup_done); |
dcf560c5 | 1598 | fail: |
1da177e4 | 1599 | BUG_ON(mm->core_waiters); |
dcf560c5 | 1600 | return core_waiters; |
1da177e4 LT |
1601 | } |
1602 | ||
6c5d5238 KH |
1603 | /* |
1604 | * set_dumpable converts traditional three-value dumpable to two flags and | |
1605 | * stores them into mm->flags. It modifies lower two bits of mm->flags, but | |
1606 | * these bits are not changed atomically. So get_dumpable can observe the | |
1607 | * intermediate state. To avoid doing unexpected behavior, get get_dumpable | |
1608 | * return either old dumpable or new one by paying attention to the order of | |
1609 | * modifying the bits. | |
1610 | * | |
1611 | * dumpable | mm->flags (binary) | |
1612 | * old new | initial interim final | |
1613 | * ---------+----------------------- | |
1614 | * 0 1 | 00 01 01 | |
1615 | * 0 2 | 00 10(*) 11 | |
1616 | * 1 0 | 01 00 00 | |
1617 | * 1 2 | 01 11 11 | |
1618 | * 2 0 | 11 10(*) 00 | |
1619 | * 2 1 | 11 11 01 | |
1620 | * | |
1621 | * (*) get_dumpable regards interim value of 10 as 11. | |
1622 | */ | |
1623 | void set_dumpable(struct mm_struct *mm, int value) | |
1624 | { | |
1625 | switch (value) { | |
1626 | case 0: | |
1627 | clear_bit(MMF_DUMPABLE, &mm->flags); | |
1628 | smp_wmb(); | |
1629 | clear_bit(MMF_DUMP_SECURELY, &mm->flags); | |
1630 | break; | |
1631 | case 1: | |
1632 | set_bit(MMF_DUMPABLE, &mm->flags); | |
1633 | smp_wmb(); | |
1634 | clear_bit(MMF_DUMP_SECURELY, &mm->flags); | |
1635 | break; | |
1636 | case 2: | |
1637 | set_bit(MMF_DUMP_SECURELY, &mm->flags); | |
1638 | smp_wmb(); | |
1639 | set_bit(MMF_DUMPABLE, &mm->flags); | |
1640 | break; | |
1641 | } | |
1642 | } | |
6c5d5238 KH |
1643 | |
1644 | int get_dumpable(struct mm_struct *mm) | |
1645 | { | |
1646 | int ret; | |
1647 | ||
1648 | ret = mm->flags & 0x3; | |
1649 | return (ret >= 2) ? 2 : ret; | |
1650 | } | |
1651 | ||
1da177e4 LT |
1652 | int do_coredump(long signr, int exit_code, struct pt_regs * regs) |
1653 | { | |
1654 | char corename[CORENAME_MAX_SIZE + 1]; | |
1655 | struct mm_struct *mm = current->mm; | |
1656 | struct linux_binfmt * binfmt; | |
1657 | struct inode * inode; | |
1658 | struct file * file; | |
1659 | int retval = 0; | |
d6e71144 AC |
1660 | int fsuid = current->fsuid; |
1661 | int flag = 0; | |
d025c9db | 1662 | int ispipe = 0; |
7dc0b22e | 1663 | unsigned long core_limit = current->signal->rlim[RLIMIT_CORE].rlim_cur; |
74aadce9 NH |
1664 | char **helper_argv = NULL; |
1665 | int helper_argc = 0; | |
1666 | char *delimit; | |
1da177e4 | 1667 | |
0a4ff8c2 SG |
1668 | audit_core_dumps(signr); |
1669 | ||
1da177e4 LT |
1670 | binfmt = current->binfmt; |
1671 | if (!binfmt || !binfmt->core_dump) | |
1672 | goto fail; | |
1673 | down_write(&mm->mmap_sem); | |
00ec99da RM |
1674 | /* |
1675 | * If another thread got here first, or we are not dumpable, bail out. | |
1676 | */ | |
1677 | if (mm->core_waiters || !get_dumpable(mm)) { | |
1da177e4 LT |
1678 | up_write(&mm->mmap_sem); |
1679 | goto fail; | |
1680 | } | |
d6e71144 AC |
1681 | |
1682 | /* | |
1683 | * We cannot trust fsuid as being the "true" uid of the | |
1684 | * process nor do we know its entire history. We only know it | |
1685 | * was tainted so we dump it as root in mode 2. | |
1686 | */ | |
6c5d5238 | 1687 | if (get_dumpable(mm) == 2) { /* Setuid core dump mode */ |
d6e71144 AC |
1688 | flag = O_EXCL; /* Stop rewrite attacks */ |
1689 | current->fsuid = 0; /* Dump root private */ | |
1690 | } | |
1291cf41 | 1691 | |
dcf560c5 ON |
1692 | retval = coredump_wait(exit_code); |
1693 | if (retval < 0) | |
1291cf41 | 1694 | goto fail; |
1da177e4 LT |
1695 | |
1696 | /* | |
1697 | * Clear any false indication of pending signals that might | |
1698 | * be seen by the filesystem code called to write the core file. | |
1699 | */ | |
1da177e4 LT |
1700 | clear_thread_flag(TIF_SIGPENDING); |
1701 | ||
1da177e4 LT |
1702 | /* |
1703 | * lock_kernel() because format_corename() is controlled by sysctl, which | |
1704 | * uses lock_kernel() | |
1705 | */ | |
1706 | lock_kernel(); | |
c4bbafda | 1707 | ispipe = format_corename(corename, core_pattern, signr); |
1da177e4 | 1708 | unlock_kernel(); |
7dc0b22e NH |
1709 | /* |
1710 | * Don't bother to check the RLIMIT_CORE value if core_pattern points | |
1711 | * to a pipe. Since we're not writing directly to the filesystem | |
1712 | * RLIMIT_CORE doesn't really apply, as no actual core file will be | |
1713 | * created unless the pipe reader choses to write out the core file | |
1714 | * at which point file size limits and permissions will be imposed | |
1715 | * as it does with any other process | |
1716 | */ | |
74aadce9 | 1717 | if ((!ispipe) && (core_limit < binfmt->min_coredump)) |
7dc0b22e NH |
1718 | goto fail_unlock; |
1719 | ||
c4bbafda | 1720 | if (ispipe) { |
74aadce9 NH |
1721 | helper_argv = argv_split(GFP_KERNEL, corename+1, &helper_argc); |
1722 | /* Terminate the string before the first option */ | |
1723 | delimit = strchr(corename, ' '); | |
1724 | if (delimit) | |
1725 | *delimit = '\0'; | |
32321137 NH |
1726 | delimit = strrchr(helper_argv[0], '/'); |
1727 | if (delimit) | |
1728 | delimit++; | |
1729 | else | |
1730 | delimit = helper_argv[0]; | |
1731 | if (!strcmp(delimit, current->comm)) { | |
1732 | printk(KERN_NOTICE "Recursive core dump detected, " | |
1733 | "aborting\n"); | |
1734 | goto fail_unlock; | |
1735 | } | |
1736 | ||
1737 | core_limit = RLIM_INFINITY; | |
1738 | ||
d025c9db | 1739 | /* SIGPIPE can happen, but it's just never processed */ |
32321137 NH |
1740 | if (call_usermodehelper_pipe(corename+1, helper_argv, NULL, |
1741 | &file)) { | |
d025c9db AK |
1742 | printk(KERN_INFO "Core dump to %s pipe failed\n", |
1743 | corename); | |
1744 | goto fail_unlock; | |
1745 | } | |
d025c9db AK |
1746 | } else |
1747 | file = filp_open(corename, | |
6d4df677 AD |
1748 | O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag, |
1749 | 0600); | |
1da177e4 LT |
1750 | if (IS_ERR(file)) |
1751 | goto fail_unlock; | |
0f7fc9e4 | 1752 | inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
1753 | if (inode->i_nlink > 1) |
1754 | goto close_fail; /* multiple links - don't dump */ | |
0f7fc9e4 | 1755 | if (!ispipe && d_unhashed(file->f_path.dentry)) |
1da177e4 LT |
1756 | goto close_fail; |
1757 | ||
d025c9db AK |
1758 | /* AK: actually i see no reason to not allow this for named pipes etc., |
1759 | but keep the previous behaviour for now. */ | |
1760 | if (!ispipe && !S_ISREG(inode->i_mode)) | |
1da177e4 | 1761 | goto close_fail; |
c46f739d IM |
1762 | /* |
1763 | * Dont allow local users get cute and trick others to coredump | |
1764 | * into their pre-created files: | |
1765 | */ | |
1766 | if (inode->i_uid != current->fsuid) | |
1767 | goto close_fail; | |
1da177e4 LT |
1768 | if (!file->f_op) |
1769 | goto close_fail; | |
1770 | if (!file->f_op->write) | |
1771 | goto close_fail; | |
0f7fc9e4 | 1772 | if (!ispipe && do_truncate(file->f_path.dentry, 0, 0, file) != 0) |
1da177e4 LT |
1773 | goto close_fail; |
1774 | ||
7dc0b22e | 1775 | retval = binfmt->core_dump(signr, regs, file, core_limit); |
1da177e4 LT |
1776 | |
1777 | if (retval) | |
1778 | current->signal->group_exit_code |= 0x80; | |
1779 | close_fail: | |
1780 | filp_close(file, NULL); | |
1781 | fail_unlock: | |
74aadce9 NH |
1782 | if (helper_argv) |
1783 | argv_free(helper_argv); | |
1784 | ||
d6e71144 | 1785 | current->fsuid = fsuid; |
1da177e4 LT |
1786 | complete_all(&mm->core_done); |
1787 | fail: | |
1788 | return retval; | |
1789 | } |