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