1 // SPDX-License-Identifier: GPL-2.0-only
5 * Copyright (C) 1991, 1992 Linus Torvalds
9 * #!-checking implemented by tytso.
12 * Demand-loading implemented 01.12.91 - no need to read anything but
13 * the header into memory. The inode of the executable is put into
14 * "current->executable", and page faults do the actual loading. Clean.
16 * Once more I can proudly say that linux stood up to being changed: it
17 * was less than 2 hours work to get demand-loading completely implemented.
19 * Demand loading changed July 1993 by Eric Youngdale. Use mmap instead,
20 * current->executable is only used by the procfs. This allows a dispatch
21 * table to check for several different types of binary formats. We keep
22 * trying until we recognize the file or we run out of supported binary
26 #include <linux/slab.h>
27 #include <linux/file.h>
28 #include <linux/fdtable.h>
30 #include <linux/vmacache.h>
31 #include <linux/stat.h>
32 #include <linux/fcntl.h>
33 #include <linux/swap.h>
34 #include <linux/string.h>
35 #include <linux/init.h>
36 #include <linux/sched/mm.h>
37 #include <linux/sched/coredump.h>
38 #include <linux/sched/signal.h>
39 #include <linux/sched/numa_balancing.h>
40 #include <linux/sched/task.h>
41 #include <linux/pagemap.h>
42 #include <linux/perf_event.h>
43 #include <linux/highmem.h>
44 #include <linux/spinlock.h>
45 #include <linux/key.h>
46 #include <linux/personality.h>
47 #include <linux/binfmts.h>
48 #include <linux/utsname.h>
49 #include <linux/pid_namespace.h>
50 #include <linux/module.h>
51 #include <linux/namei.h>
52 #include <linux/mount.h>
53 #include <linux/security.h>
54 #include <linux/syscalls.h>
55 #include <linux/tsacct_kern.h>
56 #include <linux/cn_proc.h>
57 #include <linux/audit.h>
58 #include <linux/tracehook.h>
59 #include <linux/kmod.h>
60 #include <linux/fsnotify.h>
61 #include <linux/fs_struct.h>
62 #include <linux/oom.h>
63 #include <linux/compat.h>
64 #include <linux/vmalloc.h>
66 #include <linux/uaccess.h>
67 #include <asm/mmu_context.h>
70 #include <trace/events/task.h>
73 #include <trace/events/sched.h>
75 static int bprm_creds_from_file(struct linux_binprm *bprm);
77 int suid_dumpable = 0;
79 static LIST_HEAD(formats);
80 static DEFINE_RWLOCK(binfmt_lock);
82 void __register_binfmt(struct linux_binfmt * fmt, int insert)
85 if (WARN_ON(!fmt->load_binary))
87 write_lock(&binfmt_lock);
88 insert ? list_add(&fmt->lh, &formats) :
89 list_add_tail(&fmt->lh, &formats);
90 write_unlock(&binfmt_lock);
93 EXPORT_SYMBOL(__register_binfmt);
95 void unregister_binfmt(struct linux_binfmt * fmt)
97 write_lock(&binfmt_lock);
99 write_unlock(&binfmt_lock);
102 EXPORT_SYMBOL(unregister_binfmt);
104 static inline void put_binfmt(struct linux_binfmt * fmt)
106 module_put(fmt->module);
109 bool path_noexec(const struct path *path)
111 return (path->mnt->mnt_flags & MNT_NOEXEC) ||
112 (path->mnt->mnt_sb->s_iflags & SB_I_NOEXEC);
117 * Note that a shared library must be both readable and executable due to
120 * Also note that we take the address to load from from the file itself.
122 SYSCALL_DEFINE1(uselib, const char __user *, library)
124 struct linux_binfmt *fmt;
126 struct filename *tmp = getname(library);
127 int error = PTR_ERR(tmp);
128 static const struct open_flags uselib_flags = {
129 .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC,
130 .acc_mode = MAY_READ | MAY_EXEC,
131 .intent = LOOKUP_OPEN,
132 .lookup_flags = LOOKUP_FOLLOW,
138 file = do_filp_open(AT_FDCWD, tmp, &uselib_flags);
140 error = PTR_ERR(file);
145 if (!S_ISREG(file_inode(file)->i_mode))
149 if (path_noexec(&file->f_path))
156 read_lock(&binfmt_lock);
157 list_for_each_entry(fmt, &formats, lh) {
158 if (!fmt->load_shlib)
160 if (!try_module_get(fmt->module))
162 read_unlock(&binfmt_lock);
163 error = fmt->load_shlib(file);
164 read_lock(&binfmt_lock);
166 if (error != -ENOEXEC)
169 read_unlock(&binfmt_lock);
175 #endif /* #ifdef CONFIG_USELIB */
179 * The nascent bprm->mm is not visible until exec_mmap() but it can
180 * use a lot of memory, account these pages in current->mm temporary
181 * for oom_badness()->get_mm_rss(). Once exec succeeds or fails, we
182 * change the counter back via acct_arg_size(0).
184 static void acct_arg_size(struct linux_binprm *bprm, unsigned long pages)
186 struct mm_struct *mm = current->mm;
187 long diff = (long)(pages - bprm->vma_pages);
192 bprm->vma_pages = pages;
193 add_mm_counter(mm, MM_ANONPAGES, diff);
196 static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
201 unsigned int gup_flags = FOLL_FORCE;
203 #ifdef CONFIG_STACK_GROWSUP
205 ret = expand_downwards(bprm->vma, pos);
212 gup_flags |= FOLL_WRITE;
215 * We are doing an exec(). 'current' is the process
216 * doing the exec and bprm->mm is the new process's mm.
218 ret = get_user_pages_remote(current, bprm->mm, pos, 1, gup_flags,
224 acct_arg_size(bprm, vma_pages(bprm->vma));
229 static void put_arg_page(struct page *page)
234 static void free_arg_pages(struct linux_binprm *bprm)
238 static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos,
241 flush_cache_page(bprm->vma, pos, page_to_pfn(page));
244 static int __bprm_mm_init(struct linux_binprm *bprm)
247 struct vm_area_struct *vma = NULL;
248 struct mm_struct *mm = bprm->mm;
250 bprm->vma = vma = vm_area_alloc(mm);
253 vma_set_anonymous(vma);
255 if (mmap_write_lock_killable(mm)) {
261 * Place the stack at the largest stack address the architecture
262 * supports. Later, we'll move this to an appropriate place. We don't
263 * use STACK_TOP because that can depend on attributes which aren't
266 BUILD_BUG_ON(VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUP);
267 vma->vm_end = STACK_TOP_MAX;
268 vma->vm_start = vma->vm_end - PAGE_SIZE;
269 vma->vm_flags = VM_SOFTDIRTY | VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP;
270 vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
272 err = insert_vm_struct(mm, vma);
276 mm->stack_vm = mm->total_vm = 1;
277 mmap_write_unlock(mm);
278 bprm->p = vma->vm_end - sizeof(void *);
281 mmap_write_unlock(mm);
288 static bool valid_arg_len(struct linux_binprm *bprm, long len)
290 return len <= MAX_ARG_STRLEN;
295 static inline void acct_arg_size(struct linux_binprm *bprm, unsigned long pages)
299 static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
304 page = bprm->page[pos / PAGE_SIZE];
305 if (!page && write) {
306 page = alloc_page(GFP_HIGHUSER|__GFP_ZERO);
309 bprm->page[pos / PAGE_SIZE] = page;
315 static void put_arg_page(struct page *page)
319 static void free_arg_page(struct linux_binprm *bprm, int i)
322 __free_page(bprm->page[i]);
323 bprm->page[i] = NULL;
327 static void free_arg_pages(struct linux_binprm *bprm)
331 for (i = 0; i < MAX_ARG_PAGES; i++)
332 free_arg_page(bprm, i);
335 static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos,
340 static int __bprm_mm_init(struct linux_binprm *bprm)
342 bprm->p = PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *);
346 static bool valid_arg_len(struct linux_binprm *bprm, long len)
348 return len <= bprm->p;
351 #endif /* CONFIG_MMU */
354 * Create a new mm_struct and populate it with a temporary stack
355 * vm_area_struct. We don't have enough context at this point to set the stack
356 * flags, permissions, and offset, so we use temporary values. We'll update
357 * them later in setup_arg_pages().
359 static int bprm_mm_init(struct linux_binprm *bprm)
362 struct mm_struct *mm = NULL;
364 bprm->mm = mm = mm_alloc();
369 /* Save current stack limit for all calculations made during exec. */
370 task_lock(current->group_leader);
371 bprm->rlim_stack = current->signal->rlim[RLIMIT_STACK];
372 task_unlock(current->group_leader);
374 err = __bprm_mm_init(bprm);
389 struct user_arg_ptr {
394 const char __user *const __user *native;
396 const compat_uptr_t __user *compat;
401 static const char __user *get_user_arg_ptr(struct user_arg_ptr argv, int nr)
403 const char __user *native;
406 if (unlikely(argv.is_compat)) {
407 compat_uptr_t compat;
409 if (get_user(compat, argv.ptr.compat + nr))
410 return ERR_PTR(-EFAULT);
412 return compat_ptr(compat);
416 if (get_user(native, argv.ptr.native + nr))
417 return ERR_PTR(-EFAULT);
423 * count() counts the number of strings in array ARGV.
425 static int count(struct user_arg_ptr argv, int max)
429 if (argv.ptr.native != NULL) {
431 const char __user *p = get_user_arg_ptr(argv, i);
443 if (fatal_signal_pending(current))
444 return -ERESTARTNOHAND;
451 static int count_strings_kernel(const char *const *argv)
458 for (i = 0; argv[i]; ++i) {
459 if (i >= MAX_ARG_STRINGS)
461 if (fatal_signal_pending(current))
462 return -ERESTARTNOHAND;
468 static int bprm_stack_limits(struct linux_binprm *bprm)
470 unsigned long limit, ptr_size;
473 * Limit to 1/4 of the max stack size or 3/4 of _STK_LIM
474 * (whichever is smaller) for the argv+env strings.
476 * - the remaining binfmt code will not run out of stack space,
477 * - the program will have a reasonable amount of stack left
480 limit = _STK_LIM / 4 * 3;
481 limit = min(limit, bprm->rlim_stack.rlim_cur / 4);
483 * We've historically supported up to 32 pages (ARG_MAX)
484 * of argument strings even with small stacks
486 limit = max_t(unsigned long, limit, ARG_MAX);
488 * We must account for the size of all the argv and envp pointers to
489 * the argv and envp strings, since they will also take up space in
490 * the stack. They aren't stored until much later when we can't
491 * signal to the parent that the child has run out of stack space.
492 * Instead, calculate it here so it's possible to fail gracefully.
494 ptr_size = (bprm->argc + bprm->envc) * sizeof(void *);
495 if (limit <= ptr_size)
499 bprm->argmin = bprm->p - limit;
504 * 'copy_strings()' copies argument/environment strings from the old
505 * processes's memory to the new process's stack. The call to get_user_pages()
506 * ensures the destination page is created and not swapped out.
508 static int copy_strings(int argc, struct user_arg_ptr argv,
509 struct linux_binprm *bprm)
511 struct page *kmapped_page = NULL;
513 unsigned long kpos = 0;
517 const char __user *str;
522 str = get_user_arg_ptr(argv, argc);
526 len = strnlen_user(str, MAX_ARG_STRLEN);
531 if (!valid_arg_len(bprm, len))
534 /* We're going to work our way backwords. */
539 if (bprm->p < bprm->argmin)
544 int offset, bytes_to_copy;
546 if (fatal_signal_pending(current)) {
547 ret = -ERESTARTNOHAND;
552 offset = pos % PAGE_SIZE;
556 bytes_to_copy = offset;
557 if (bytes_to_copy > len)
560 offset -= bytes_to_copy;
561 pos -= bytes_to_copy;
562 str -= bytes_to_copy;
563 len -= bytes_to_copy;
565 if (!kmapped_page || kpos != (pos & PAGE_MASK)) {
568 page = get_arg_page(bprm, pos, 1);
575 flush_kernel_dcache_page(kmapped_page);
576 kunmap(kmapped_page);
577 put_arg_page(kmapped_page);
580 kaddr = kmap(kmapped_page);
581 kpos = pos & PAGE_MASK;
582 flush_arg_page(bprm, kpos, kmapped_page);
584 if (copy_from_user(kaddr+offset, str, bytes_to_copy)) {
593 flush_kernel_dcache_page(kmapped_page);
594 kunmap(kmapped_page);
595 put_arg_page(kmapped_page);
601 * Copy and argument/environment string from the kernel to the processes stack.
603 int copy_string_kernel(const char *arg, struct linux_binprm *bprm)
605 int len = strnlen(arg, MAX_ARG_STRLEN) + 1 /* terminating NUL */;
606 unsigned long pos = bprm->p;
610 if (!valid_arg_len(bprm, len))
613 /* We're going to work our way backwards. */
616 if (IS_ENABLED(CONFIG_MMU) && bprm->p < bprm->argmin)
620 unsigned int bytes_to_copy = min_t(unsigned int, len,
621 min_not_zero(offset_in_page(pos), PAGE_SIZE));
625 pos -= bytes_to_copy;
626 arg -= bytes_to_copy;
627 len -= bytes_to_copy;
629 page = get_arg_page(bprm, pos, 1);
632 kaddr = kmap_atomic(page);
633 flush_arg_page(bprm, pos & PAGE_MASK, page);
634 memcpy(kaddr + offset_in_page(pos), arg, bytes_to_copy);
635 flush_kernel_dcache_page(page);
636 kunmap_atomic(kaddr);
642 EXPORT_SYMBOL(copy_string_kernel);
644 static int copy_strings_kernel(int argc, const char *const *argv,
645 struct linux_binprm *bprm)
648 int ret = copy_string_kernel(argv[argc], bprm);
651 if (fatal_signal_pending(current))
652 return -ERESTARTNOHAND;
661 * During bprm_mm_init(), we create a temporary stack at STACK_TOP_MAX. Once
662 * the binfmt code determines where the new stack should reside, we shift it to
663 * its final location. The process proceeds as follows:
665 * 1) Use shift to calculate the new vma endpoints.
666 * 2) Extend vma to cover both the old and new ranges. This ensures the
667 * arguments passed to subsequent functions are consistent.
668 * 3) Move vma's page tables to the new range.
669 * 4) Free up any cleared pgd range.
670 * 5) Shrink the vma to cover only the new range.
672 static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift)
674 struct mm_struct *mm = vma->vm_mm;
675 unsigned long old_start = vma->vm_start;
676 unsigned long old_end = vma->vm_end;
677 unsigned long length = old_end - old_start;
678 unsigned long new_start = old_start - shift;
679 unsigned long new_end = old_end - shift;
680 struct mmu_gather tlb;
682 BUG_ON(new_start > new_end);
685 * ensure there are no vmas between where we want to go
688 if (vma != find_vma(mm, new_start))
692 * cover the whole range: [new_start, old_end)
694 if (vma_adjust(vma, new_start, old_end, vma->vm_pgoff, NULL))
698 * move the page tables downwards, on failure we rely on
699 * process cleanup to remove whatever mess we made.
701 if (length != move_page_tables(vma, old_start,
702 vma, new_start, length, false))
706 tlb_gather_mmu(&tlb, mm, old_start, old_end);
707 if (new_end > old_start) {
709 * when the old and new regions overlap clear from new_end.
711 free_pgd_range(&tlb, new_end, old_end, new_end,
712 vma->vm_next ? vma->vm_next->vm_start : USER_PGTABLES_CEILING);
715 * otherwise, clean from old_start; this is done to not touch
716 * the address space in [new_end, old_start) some architectures
717 * have constraints on va-space that make this illegal (IA64) -
718 * for the others its just a little faster.
720 free_pgd_range(&tlb, old_start, old_end, new_end,
721 vma->vm_next ? vma->vm_next->vm_start : USER_PGTABLES_CEILING);
723 tlb_finish_mmu(&tlb, old_start, old_end);
726 * Shrink the vma to just the new range. Always succeeds.
728 vma_adjust(vma, new_start, new_end, vma->vm_pgoff, NULL);
734 * Finalizes the stack vm_area_struct. The flags and permissions are updated,
735 * the stack is optionally relocated, and some extra space is added.
737 int setup_arg_pages(struct linux_binprm *bprm,
738 unsigned long stack_top,
739 int executable_stack)
742 unsigned long stack_shift;
743 struct mm_struct *mm = current->mm;
744 struct vm_area_struct *vma = bprm->vma;
745 struct vm_area_struct *prev = NULL;
746 unsigned long vm_flags;
747 unsigned long stack_base;
748 unsigned long stack_size;
749 unsigned long stack_expand;
750 unsigned long rlim_stack;
752 #ifdef CONFIG_STACK_GROWSUP
753 /* Limit stack size */
754 stack_base = bprm->rlim_stack.rlim_max;
755 if (stack_base > STACK_SIZE_MAX)
756 stack_base = STACK_SIZE_MAX;
758 /* Add space for stack randomization. */
759 stack_base += (STACK_RND_MASK << PAGE_SHIFT);
761 /* Make sure we didn't let the argument array grow too large. */
762 if (vma->vm_end - vma->vm_start > stack_base)
765 stack_base = PAGE_ALIGN(stack_top - stack_base);
767 stack_shift = vma->vm_start - stack_base;
768 mm->arg_start = bprm->p - stack_shift;
769 bprm->p = vma->vm_end - stack_shift;
771 stack_top = arch_align_stack(stack_top);
772 stack_top = PAGE_ALIGN(stack_top);
774 if (unlikely(stack_top < mmap_min_addr) ||
775 unlikely(vma->vm_end - vma->vm_start >= stack_top - mmap_min_addr))
778 stack_shift = vma->vm_end - stack_top;
780 bprm->p -= stack_shift;
781 mm->arg_start = bprm->p;
785 bprm->loader -= stack_shift;
786 bprm->exec -= stack_shift;
788 if (mmap_write_lock_killable(mm))
791 vm_flags = VM_STACK_FLAGS;
794 * Adjust stack execute permissions; explicitly enable for
795 * EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X and leave alone
796 * (arch default) otherwise.
798 if (unlikely(executable_stack == EXSTACK_ENABLE_X))
800 else if (executable_stack == EXSTACK_DISABLE_X)
801 vm_flags &= ~VM_EXEC;
802 vm_flags |= mm->def_flags;
803 vm_flags |= VM_STACK_INCOMPLETE_SETUP;
805 ret = mprotect_fixup(vma, &prev, vma->vm_start, vma->vm_end,
811 if (unlikely(vm_flags & VM_EXEC)) {
812 pr_warn_once("process '%pD4' started with executable stack\n",
816 /* Move stack pages down in memory. */
818 ret = shift_arg_pages(vma, stack_shift);
823 /* mprotect_fixup is overkill to remove the temporary stack flags */
824 vma->vm_flags &= ~VM_STACK_INCOMPLETE_SETUP;
826 stack_expand = 131072UL; /* randomly 32*4k (or 2*64k) pages */
827 stack_size = vma->vm_end - vma->vm_start;
829 * Align this down to a page boundary as expand_stack
832 rlim_stack = bprm->rlim_stack.rlim_cur & PAGE_MASK;
833 #ifdef CONFIG_STACK_GROWSUP
834 if (stack_size + stack_expand > rlim_stack)
835 stack_base = vma->vm_start + rlim_stack;
837 stack_base = vma->vm_end + stack_expand;
839 if (stack_size + stack_expand > rlim_stack)
840 stack_base = vma->vm_end - rlim_stack;
842 stack_base = vma->vm_start - stack_expand;
844 current->mm->start_stack = bprm->p;
845 ret = expand_stack(vma, stack_base);
850 mmap_write_unlock(mm);
853 EXPORT_SYMBOL(setup_arg_pages);
858 * Transfer the program arguments and environment from the holding pages
859 * onto the stack. The provided stack pointer is adjusted accordingly.
861 int transfer_args_to_stack(struct linux_binprm *bprm,
862 unsigned long *sp_location)
864 unsigned long index, stop, sp;
867 stop = bprm->p >> PAGE_SHIFT;
870 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
871 unsigned int offset = index == stop ? bprm->p & ~PAGE_MASK : 0;
872 char *src = kmap(bprm->page[index]) + offset;
873 sp -= PAGE_SIZE - offset;
874 if (copy_to_user((void *) sp, src, PAGE_SIZE - offset) != 0)
876 kunmap(bprm->page[index]);
886 EXPORT_SYMBOL(transfer_args_to_stack);
888 #endif /* CONFIG_MMU */
890 static struct file *do_open_execat(int fd, struct filename *name, int flags)
894 struct open_flags open_exec_flags = {
895 .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC,
896 .acc_mode = MAY_EXEC,
897 .intent = LOOKUP_OPEN,
898 .lookup_flags = LOOKUP_FOLLOW,
901 if ((flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0)
902 return ERR_PTR(-EINVAL);
903 if (flags & AT_SYMLINK_NOFOLLOW)
904 open_exec_flags.lookup_flags &= ~LOOKUP_FOLLOW;
905 if (flags & AT_EMPTY_PATH)
906 open_exec_flags.lookup_flags |= LOOKUP_EMPTY;
908 file = do_filp_open(fd, name, &open_exec_flags);
913 if (!S_ISREG(file_inode(file)->i_mode))
916 if (path_noexec(&file->f_path))
919 err = deny_write_access(file);
923 if (name->name[0] != '\0')
934 struct file *open_exec(const char *name)
936 struct filename *filename = getname_kernel(name);
937 struct file *f = ERR_CAST(filename);
939 if (!IS_ERR(filename)) {
940 f = do_open_execat(AT_FDCWD, filename, 0);
945 EXPORT_SYMBOL(open_exec);
947 int kernel_read_file(struct file *file, void **buf, loff_t *size,
948 loff_t max_size, enum kernel_read_file_id id)
954 if (!S_ISREG(file_inode(file)->i_mode) || max_size < 0)
957 ret = deny_write_access(file);
961 ret = security_kernel_read_file(file, id);
965 i_size = i_size_read(file_inode(file));
970 if (i_size > SIZE_MAX || (max_size > 0 && i_size > max_size)) {
975 if (id != READING_FIRMWARE_PREALLOC_BUFFER)
976 *buf = vmalloc(i_size);
983 while (pos < i_size) {
984 bytes = kernel_read(file, *buf + pos, i_size - pos, &pos);
999 ret = security_kernel_post_read_file(file, *buf, i_size, id);
1005 if (id != READING_FIRMWARE_PREALLOC_BUFFER) {
1012 allow_write_access(file);
1015 EXPORT_SYMBOL_GPL(kernel_read_file);
1017 int kernel_read_file_from_path(const char *path, void **buf, loff_t *size,
1018 loff_t max_size, enum kernel_read_file_id id)
1023 if (!path || !*path)
1026 file = filp_open(path, O_RDONLY, 0);
1028 return PTR_ERR(file);
1030 ret = kernel_read_file(file, buf, size, max_size, id);
1034 EXPORT_SYMBOL_GPL(kernel_read_file_from_path);
1036 int kernel_read_file_from_path_initns(const char *path, void **buf,
1037 loff_t *size, loff_t max_size,
1038 enum kernel_read_file_id id)
1044 if (!path || !*path)
1047 task_lock(&init_task);
1048 get_fs_root(init_task.fs, &root);
1049 task_unlock(&init_task);
1051 file = file_open_root(root.dentry, root.mnt, path, O_RDONLY, 0);
1054 return PTR_ERR(file);
1056 ret = kernel_read_file(file, buf, size, max_size, id);
1060 EXPORT_SYMBOL_GPL(kernel_read_file_from_path_initns);
1062 int kernel_read_file_from_fd(int fd, void **buf, loff_t *size, loff_t max_size,
1063 enum kernel_read_file_id id)
1065 struct fd f = fdget(fd);
1071 ret = kernel_read_file(f.file, buf, size, max_size, id);
1076 EXPORT_SYMBOL_GPL(kernel_read_file_from_fd);
1078 #if defined(CONFIG_HAVE_AOUT) || defined(CONFIG_BINFMT_FLAT) || \
1079 defined(CONFIG_BINFMT_ELF_FDPIC)
1080 ssize_t read_code(struct file *file, unsigned long addr, loff_t pos, size_t len)
1082 ssize_t res = vfs_read(file, (void __user *)addr, len, &pos);
1084 flush_icache_user_range(addr, addr + len);
1087 EXPORT_SYMBOL(read_code);
1091 * Maps the mm_struct mm into the current task struct.
1092 * On success, this function returns with the mutex
1093 * exec_update_mutex locked.
1095 static int exec_mmap(struct mm_struct *mm)
1097 struct task_struct *tsk;
1098 struct mm_struct *old_mm, *active_mm;
1101 /* Notify parent that we're no longer interested in the old VM */
1103 old_mm = current->mm;
1104 exec_mm_release(tsk, old_mm);
1106 sync_mm_rss(old_mm);
1108 ret = mutex_lock_killable(&tsk->signal->exec_update_mutex);
1114 * Make sure that if there is a core dump in progress
1115 * for the old mm, we get out and die instead of going
1116 * through with the exec. We must hold mmap_lock around
1117 * checking core_state and changing tsk->mm.
1119 mmap_read_lock(old_mm);
1120 if (unlikely(old_mm->core_state)) {
1121 mmap_read_unlock(old_mm);
1122 mutex_unlock(&tsk->signal->exec_update_mutex);
1128 active_mm = tsk->active_mm;
1129 membarrier_exec_mmap(mm);
1131 tsk->active_mm = mm;
1132 activate_mm(active_mm, mm);
1133 tsk->mm->vmacache_seqnum = 0;
1134 vmacache_flush(tsk);
1137 mmap_read_unlock(old_mm);
1138 BUG_ON(active_mm != old_mm);
1139 setmax_mm_hiwater_rss(&tsk->signal->maxrss, old_mm);
1140 mm_update_next_owner(old_mm);
1148 static int de_thread(struct task_struct *tsk)
1150 struct signal_struct *sig = tsk->signal;
1151 struct sighand_struct *oldsighand = tsk->sighand;
1152 spinlock_t *lock = &oldsighand->siglock;
1154 if (thread_group_empty(tsk))
1155 goto no_thread_group;
1158 * Kill all other threads in the thread group.
1160 spin_lock_irq(lock);
1161 if (signal_group_exit(sig)) {
1163 * Another group action in progress, just
1164 * return so that the signal is processed.
1166 spin_unlock_irq(lock);
1170 sig->group_exit_task = tsk;
1171 sig->notify_count = zap_other_threads(tsk);
1172 if (!thread_group_leader(tsk))
1173 sig->notify_count--;
1175 while (sig->notify_count) {
1176 __set_current_state(TASK_KILLABLE);
1177 spin_unlock_irq(lock);
1179 if (__fatal_signal_pending(tsk))
1181 spin_lock_irq(lock);
1183 spin_unlock_irq(lock);
1186 * At this point all other threads have exited, all we have to
1187 * do is to wait for the thread group leader to become inactive,
1188 * and to assume its PID:
1190 if (!thread_group_leader(tsk)) {
1191 struct task_struct *leader = tsk->group_leader;
1194 cgroup_threadgroup_change_begin(tsk);
1195 write_lock_irq(&tasklist_lock);
1197 * Do this under tasklist_lock to ensure that
1198 * exit_notify() can't miss ->group_exit_task
1200 sig->notify_count = -1;
1201 if (likely(leader->exit_state))
1203 __set_current_state(TASK_KILLABLE);
1204 write_unlock_irq(&tasklist_lock);
1205 cgroup_threadgroup_change_end(tsk);
1207 if (__fatal_signal_pending(tsk))
1212 * The only record we have of the real-time age of a
1213 * process, regardless of execs it's done, is start_time.
1214 * All the past CPU time is accumulated in signal_struct
1215 * from sister threads now dead. But in this non-leader
1216 * exec, nothing survives from the original leader thread,
1217 * whose birth marks the true age of this process now.
1218 * When we take on its identity by switching to its PID, we
1219 * also take its birthdate (always earlier than our own).
1221 tsk->start_time = leader->start_time;
1222 tsk->start_boottime = leader->start_boottime;
1224 BUG_ON(!same_thread_group(leader, tsk));
1226 * An exec() starts a new thread group with the
1227 * TGID of the previous thread group. Rehash the
1228 * two threads with a switched PID, and release
1229 * the former thread group leader:
1232 /* Become a process group leader with the old leader's pid.
1233 * The old leader becomes a thread of the this thread group.
1235 exchange_tids(tsk, leader);
1236 transfer_pid(leader, tsk, PIDTYPE_TGID);
1237 transfer_pid(leader, tsk, PIDTYPE_PGID);
1238 transfer_pid(leader, tsk, PIDTYPE_SID);
1240 list_replace_rcu(&leader->tasks, &tsk->tasks);
1241 list_replace_init(&leader->sibling, &tsk->sibling);
1243 tsk->group_leader = tsk;
1244 leader->group_leader = tsk;
1246 tsk->exit_signal = SIGCHLD;
1247 leader->exit_signal = -1;
1249 BUG_ON(leader->exit_state != EXIT_ZOMBIE);
1250 leader->exit_state = EXIT_DEAD;
1253 * We are going to release_task()->ptrace_unlink() silently,
1254 * the tracer can sleep in do_wait(). EXIT_DEAD guarantees
1255 * the tracer wont't block again waiting for this thread.
1257 if (unlikely(leader->ptrace))
1258 __wake_up_parent(leader, leader->parent);
1259 write_unlock_irq(&tasklist_lock);
1260 cgroup_threadgroup_change_end(tsk);
1262 release_task(leader);
1265 sig->group_exit_task = NULL;
1266 sig->notify_count = 0;
1269 /* we have changed execution domain */
1270 tsk->exit_signal = SIGCHLD;
1272 BUG_ON(!thread_group_leader(tsk));
1276 /* protects against exit_notify() and __exit_signal() */
1277 read_lock(&tasklist_lock);
1278 sig->group_exit_task = NULL;
1279 sig->notify_count = 0;
1280 read_unlock(&tasklist_lock);
1286 * This function makes sure the current process has its own signal table,
1287 * so that flush_signal_handlers can later reset the handlers without
1288 * disturbing other processes. (Other processes might share the signal
1289 * table via the CLONE_SIGHAND option to clone().)
1291 static int unshare_sighand(struct task_struct *me)
1293 struct sighand_struct *oldsighand = me->sighand;
1295 if (refcount_read(&oldsighand->count) != 1) {
1296 struct sighand_struct *newsighand;
1298 * This ->sighand is shared with the CLONE_SIGHAND
1299 * but not CLONE_THREAD task, switch to the new one.
1301 newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL);
1305 refcount_set(&newsighand->count, 1);
1306 memcpy(newsighand->action, oldsighand->action,
1307 sizeof(newsighand->action));
1309 write_lock_irq(&tasklist_lock);
1310 spin_lock(&oldsighand->siglock);
1311 rcu_assign_pointer(me->sighand, newsighand);
1312 spin_unlock(&oldsighand->siglock);
1313 write_unlock_irq(&tasklist_lock);
1315 __cleanup_sighand(oldsighand);
1320 char *__get_task_comm(char *buf, size_t buf_size, struct task_struct *tsk)
1323 strncpy(buf, tsk->comm, buf_size);
1327 EXPORT_SYMBOL_GPL(__get_task_comm);
1330 * These functions flushes out all traces of the currently running executable
1331 * so that a new one can be started
1334 void __set_task_comm(struct task_struct *tsk, const char *buf, bool exec)
1337 trace_task_rename(tsk, buf);
1338 strlcpy(tsk->comm, buf, sizeof(tsk->comm));
1340 perf_event_comm(tsk, exec);
1344 * Calling this is the point of no return. None of the failures will be
1345 * seen by userspace since either the process is already taking a fatal
1346 * signal (via de_thread() or coredump), or will have SEGV raised
1347 * (after exec_mmap()) by search_binary_handler (see below).
1349 int begin_new_exec(struct linux_binprm * bprm)
1351 struct task_struct *me = current;
1354 /* Once we are committed compute the creds */
1355 retval = bprm_creds_from_file(bprm);
1360 * Ensure all future errors are fatal.
1362 bprm->point_of_no_return = true;
1365 * Make this the only thread in the thread group.
1367 retval = de_thread(me);
1372 * Must be called _before_ exec_mmap() as bprm->mm is
1373 * not visibile until then. This also enables the update
1376 set_mm_exe_file(bprm->mm, bprm->file);
1378 /* If the binary is not readable then enforce mm->dumpable=0 */
1379 would_dump(bprm, bprm->file);
1380 if (bprm->have_execfd)
1381 would_dump(bprm, bprm->executable);
1384 * Release all of the old mmap stuff
1386 acct_arg_size(bprm, 0);
1387 retval = exec_mmap(bprm->mm);
1393 #ifdef CONFIG_POSIX_TIMERS
1394 exit_itimers(me->signal);
1395 flush_itimer_signals();
1399 * Make the signal table private.
1401 retval = unshare_sighand(me);
1406 me->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD |
1407 PF_NOFREEZE | PF_NO_SETAFFINITY);
1409 me->personality &= ~bprm->per_clear;
1412 * We have to apply CLOEXEC before we change whether the process is
1413 * dumpable (in setup_new_exec) to avoid a race with a process in userspace
1414 * trying to access the should-be-closed file descriptors of a process
1415 * undergoing exec(2).
1417 do_close_on_exec(me->files);
1419 if (bprm->secureexec) {
1420 /* Make sure parent cannot signal privileged process. */
1421 me->pdeath_signal = 0;
1424 * For secureexec, reset the stack limit to sane default to
1425 * avoid bad behavior from the prior rlimits. This has to
1426 * happen before arch_pick_mmap_layout(), which examines
1427 * RLIMIT_STACK, but after the point of no return to avoid
1428 * needing to clean up the change on failure.
1430 if (bprm->rlim_stack.rlim_cur > _STK_LIM)
1431 bprm->rlim_stack.rlim_cur = _STK_LIM;
1434 me->sas_ss_sp = me->sas_ss_size = 0;
1437 * Figure out dumpability. Note that this checking only of current
1438 * is wrong, but userspace depends on it. This should be testing
1439 * bprm->secureexec instead.
1441 if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP ||
1442 !(uid_eq(current_euid(), current_uid()) &&
1443 gid_eq(current_egid(), current_gid())))
1444 set_dumpable(current->mm, suid_dumpable);
1446 set_dumpable(current->mm, SUID_DUMP_USER);
1449 __set_task_comm(me, kbasename(bprm->filename), true);
1451 /* An exec changes our domain. We are no longer part of the thread
1453 WRITE_ONCE(me->self_exec_id, me->self_exec_id + 1);
1454 flush_signal_handlers(me, 0);
1457 * install the new credentials for this executable
1459 security_bprm_committing_creds(bprm);
1461 commit_creds(bprm->cred);
1465 * Disable monitoring for regular users
1466 * when executing setuid binaries. Must
1467 * wait until new credentials are committed
1468 * by commit_creds() above
1470 if (get_dumpable(me->mm) != SUID_DUMP_USER)
1471 perf_event_exit_task(me);
1473 * cred_guard_mutex must be held at least to this point to prevent
1474 * ptrace_attach() from altering our determination of the task's
1475 * credentials; any time after this it may be unlocked.
1477 security_bprm_committed_creds(bprm);
1479 /* Pass the opened binary to the interpreter. */
1480 if (bprm->have_execfd) {
1481 retval = get_unused_fd_flags(0);
1484 fd_install(retval, bprm->executable);
1485 bprm->executable = NULL;
1486 bprm->execfd = retval;
1491 mutex_unlock(&me->signal->exec_update_mutex);
1495 EXPORT_SYMBOL(begin_new_exec);
1497 void would_dump(struct linux_binprm *bprm, struct file *file)
1499 struct inode *inode = file_inode(file);
1500 if (inode_permission(inode, MAY_READ) < 0) {
1501 struct user_namespace *old, *user_ns;
1502 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
1504 /* Ensure mm->user_ns contains the executable */
1505 user_ns = old = bprm->mm->user_ns;
1506 while ((user_ns != &init_user_ns) &&
1507 !privileged_wrt_inode_uidgid(user_ns, inode))
1508 user_ns = user_ns->parent;
1510 if (old != user_ns) {
1511 bprm->mm->user_ns = get_user_ns(user_ns);
1516 EXPORT_SYMBOL(would_dump);
1518 void setup_new_exec(struct linux_binprm * bprm)
1520 /* Setup things that can depend upon the personality */
1521 struct task_struct *me = current;
1523 arch_pick_mmap_layout(me->mm, &bprm->rlim_stack);
1525 arch_setup_new_exec();
1527 /* Set the new mm task size. We have to do that late because it may
1528 * depend on TIF_32BIT which is only updated in flush_thread() on
1529 * some architectures like powerpc
1531 me->mm->task_size = TASK_SIZE;
1532 mutex_unlock(&me->signal->exec_update_mutex);
1533 mutex_unlock(&me->signal->cred_guard_mutex);
1535 EXPORT_SYMBOL(setup_new_exec);
1537 /* Runs immediately before start_thread() takes over. */
1538 void finalize_exec(struct linux_binprm *bprm)
1540 /* Store any stack rlimit changes before starting thread. */
1541 task_lock(current->group_leader);
1542 current->signal->rlim[RLIMIT_STACK] = bprm->rlim_stack;
1543 task_unlock(current->group_leader);
1545 EXPORT_SYMBOL(finalize_exec);
1548 * Prepare credentials and lock ->cred_guard_mutex.
1549 * setup_new_exec() commits the new creds and drops the lock.
1550 * Or, if exec fails before, free_bprm() should release ->cred and
1553 static int prepare_bprm_creds(struct linux_binprm *bprm)
1555 if (mutex_lock_interruptible(¤t->signal->cred_guard_mutex))
1556 return -ERESTARTNOINTR;
1558 bprm->cred = prepare_exec_creds();
1559 if (likely(bprm->cred))
1562 mutex_unlock(¤t->signal->cred_guard_mutex);
1566 static void free_bprm(struct linux_binprm *bprm)
1569 acct_arg_size(bprm, 0);
1572 free_arg_pages(bprm);
1574 mutex_unlock(¤t->signal->cred_guard_mutex);
1575 abort_creds(bprm->cred);
1578 allow_write_access(bprm->file);
1581 if (bprm->executable)
1582 fput(bprm->executable);
1583 /* If a binfmt changed the interp, free it. */
1584 if (bprm->interp != bprm->filename)
1585 kfree(bprm->interp);
1586 kfree(bprm->fdpath);
1590 static struct linux_binprm *alloc_bprm(int fd, struct filename *filename)
1592 struct linux_binprm *bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
1593 int retval = -ENOMEM;
1597 if (fd == AT_FDCWD || filename->name[0] == '/') {
1598 bprm->filename = filename->name;
1600 if (filename->name[0] == '\0')
1601 bprm->fdpath = kasprintf(GFP_KERNEL, "/dev/fd/%d", fd);
1603 bprm->fdpath = kasprintf(GFP_KERNEL, "/dev/fd/%d/%s",
1604 fd, filename->name);
1608 bprm->filename = bprm->fdpath;
1610 bprm->interp = bprm->filename;
1612 retval = bprm_mm_init(bprm);
1620 return ERR_PTR(retval);
1623 int bprm_change_interp(const char *interp, struct linux_binprm *bprm)
1625 /* If a binfmt changed the interp, free it first. */
1626 if (bprm->interp != bprm->filename)
1627 kfree(bprm->interp);
1628 bprm->interp = kstrdup(interp, GFP_KERNEL);
1633 EXPORT_SYMBOL(bprm_change_interp);
1636 * determine how safe it is to execute the proposed program
1637 * - the caller must hold ->cred_guard_mutex to protect against
1638 * PTRACE_ATTACH or seccomp thread-sync
1640 static void check_unsafe_exec(struct linux_binprm *bprm)
1642 struct task_struct *p = current, *t;
1646 bprm->unsafe |= LSM_UNSAFE_PTRACE;
1649 * This isn't strictly necessary, but it makes it harder for LSMs to
1652 if (task_no_new_privs(current))
1653 bprm->unsafe |= LSM_UNSAFE_NO_NEW_PRIVS;
1657 spin_lock(&p->fs->lock);
1659 while_each_thread(p, t) {
1665 if (p->fs->users > n_fs)
1666 bprm->unsafe |= LSM_UNSAFE_SHARE;
1669 spin_unlock(&p->fs->lock);
1672 static void bprm_fill_uid(struct linux_binprm *bprm, struct file *file)
1674 /* Handle suid and sgid on files */
1675 struct inode *inode;
1680 if (!mnt_may_suid(file->f_path.mnt))
1683 if (task_no_new_privs(current))
1686 inode = file->f_path.dentry->d_inode;
1687 mode = READ_ONCE(inode->i_mode);
1688 if (!(mode & (S_ISUID|S_ISGID)))
1691 /* Be careful if suid/sgid is set */
1694 /* reload atomically mode/uid/gid now that lock held */
1695 mode = inode->i_mode;
1698 inode_unlock(inode);
1700 /* We ignore suid/sgid if there are no mappings for them in the ns */
1701 if (!kuid_has_mapping(bprm->cred->user_ns, uid) ||
1702 !kgid_has_mapping(bprm->cred->user_ns, gid))
1705 if (mode & S_ISUID) {
1706 bprm->per_clear |= PER_CLEAR_ON_SETID;
1707 bprm->cred->euid = uid;
1710 if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
1711 bprm->per_clear |= PER_CLEAR_ON_SETID;
1712 bprm->cred->egid = gid;
1717 * Compute brpm->cred based upon the final binary.
1719 static int bprm_creds_from_file(struct linux_binprm *bprm)
1721 /* Compute creds based on which file? */
1722 struct file *file = bprm->execfd_creds ? bprm->executable : bprm->file;
1724 bprm_fill_uid(bprm, file);
1725 return security_bprm_creds_from_file(bprm, file);
1729 * Fill the binprm structure from the inode.
1730 * Read the first BINPRM_BUF_SIZE bytes
1732 * This may be called multiple times for binary chains (scripts for example).
1734 static int prepare_binprm(struct linux_binprm *bprm)
1738 memset(bprm->buf, 0, BINPRM_BUF_SIZE);
1739 return kernel_read(bprm->file, bprm->buf, BINPRM_BUF_SIZE, &pos);
1743 * Arguments are '\0' separated strings found at the location bprm->p
1744 * points to; chop off the first by relocating brpm->p to right after
1745 * the first '\0' encountered.
1747 int remove_arg_zero(struct linux_binprm *bprm)
1750 unsigned long offset;
1758 offset = bprm->p & ~PAGE_MASK;
1759 page = get_arg_page(bprm, bprm->p, 0);
1764 kaddr = kmap_atomic(page);
1766 for (; offset < PAGE_SIZE && kaddr[offset];
1767 offset++, bprm->p++)
1770 kunmap_atomic(kaddr);
1772 } while (offset == PAGE_SIZE);
1781 EXPORT_SYMBOL(remove_arg_zero);
1783 #define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e))
1785 * cycle the list of binary formats handler, until one recognizes the image
1787 static int search_binary_handler(struct linux_binprm *bprm)
1789 bool need_retry = IS_ENABLED(CONFIG_MODULES);
1790 struct linux_binfmt *fmt;
1793 retval = prepare_binprm(bprm);
1797 retval = security_bprm_check(bprm);
1803 read_lock(&binfmt_lock);
1804 list_for_each_entry(fmt, &formats, lh) {
1805 if (!try_module_get(fmt->module))
1807 read_unlock(&binfmt_lock);
1809 retval = fmt->load_binary(bprm);
1811 read_lock(&binfmt_lock);
1813 if (bprm->point_of_no_return || (retval != -ENOEXEC)) {
1814 read_unlock(&binfmt_lock);
1818 read_unlock(&binfmt_lock);
1821 if (printable(bprm->buf[0]) && printable(bprm->buf[1]) &&
1822 printable(bprm->buf[2]) && printable(bprm->buf[3]))
1824 if (request_module("binfmt-%04x", *(ushort *)(bprm->buf + 2)) < 0)
1833 static int exec_binprm(struct linux_binprm *bprm)
1835 pid_t old_pid, old_vpid;
1838 /* Need to fetch pid before load_binary changes it */
1839 old_pid = current->pid;
1841 old_vpid = task_pid_nr_ns(current, task_active_pid_ns(current->parent));
1844 /* This allows 4 levels of binfmt rewrites before failing hard. */
1845 for (depth = 0;; depth++) {
1850 ret = search_binary_handler(bprm);
1853 if (!bprm->interpreter)
1857 bprm->file = bprm->interpreter;
1858 bprm->interpreter = NULL;
1860 allow_write_access(exec);
1861 if (unlikely(bprm->have_execfd)) {
1862 if (bprm->executable) {
1866 bprm->executable = exec;
1872 trace_sched_process_exec(current, old_pid, bprm);
1873 ptrace_event(PTRACE_EVENT_EXEC, old_vpid);
1874 proc_exec_connector(current);
1879 * sys_execve() executes a new program.
1881 static int bprm_execve(struct linux_binprm *bprm,
1882 int fd, struct filename *filename, int flags)
1885 struct files_struct *displaced;
1888 retval = unshare_files(&displaced);
1892 retval = prepare_bprm_creds(bprm);
1896 check_unsafe_exec(bprm);
1897 current->in_execve = 1;
1899 file = do_open_execat(fd, filename, flags);
1900 retval = PTR_ERR(file);
1908 * Record that a name derived from an O_CLOEXEC fd will be
1909 * inaccessible after exec. Relies on having exclusive access to
1910 * current->files (due to unshare_files above).
1913 close_on_exec(fd, rcu_dereference_raw(current->files->fdt)))
1914 bprm->interp_flags |= BINPRM_FLAGS_PATH_INACCESSIBLE;
1916 /* Set the unchanging part of bprm->cred */
1917 retval = security_bprm_creds_for_exec(bprm);
1921 retval = exec_binprm(bprm);
1925 /* execve succeeded */
1926 current->fs->in_exec = 0;
1927 current->in_execve = 0;
1928 rseq_execve(current);
1929 acct_update_integrals(current);
1930 task_numa_free(current, false);
1932 put_files_struct(displaced);
1937 * If past the point of no return ensure the the code never
1938 * returns to the userspace process. Use an existing fatal
1939 * signal if present otherwise terminate the process with
1942 if (bprm->point_of_no_return && !fatal_signal_pending(current))
1943 force_sigsegv(SIGSEGV);
1946 current->fs->in_exec = 0;
1947 current->in_execve = 0;
1951 reset_files_struct(displaced);
1956 static int do_execveat_common(int fd, struct filename *filename,
1957 struct user_arg_ptr argv,
1958 struct user_arg_ptr envp,
1961 struct linux_binprm *bprm;
1964 if (IS_ERR(filename))
1965 return PTR_ERR(filename);
1968 * We move the actual failure in case of RLIMIT_NPROC excess from
1969 * set*uid() to execve() because too many poorly written programs
1970 * don't check setuid() return code. Here we additionally recheck
1971 * whether NPROC limit is still exceeded.
1973 if ((current->flags & PF_NPROC_EXCEEDED) &&
1974 atomic_read(¤t_user()->processes) > rlimit(RLIMIT_NPROC)) {
1979 /* We're below the limit (still or again), so we don't want to make
1980 * further execve() calls fail. */
1981 current->flags &= ~PF_NPROC_EXCEEDED;
1983 bprm = alloc_bprm(fd, filename);
1985 retval = PTR_ERR(bprm);
1989 retval = count(argv, MAX_ARG_STRINGS);
1992 bprm->argc = retval;
1994 retval = count(envp, MAX_ARG_STRINGS);
1997 bprm->envc = retval;
1999 retval = bprm_stack_limits(bprm);
2003 retval = copy_string_kernel(bprm->filename, bprm);
2006 bprm->exec = bprm->p;
2008 retval = copy_strings(bprm->envc, envp, bprm);
2012 retval = copy_strings(bprm->argc, argv, bprm);
2016 retval = bprm_execve(bprm, fd, filename, flags);
2025 int kernel_execve(const char *kernel_filename,
2026 const char *const *argv, const char *const *envp)
2028 struct filename *filename;
2029 struct linux_binprm *bprm;
2033 filename = getname_kernel(kernel_filename);
2034 if (IS_ERR(filename))
2035 return PTR_ERR(filename);
2037 bprm = alloc_bprm(fd, filename);
2039 retval = PTR_ERR(bprm);
2043 retval = count_strings_kernel(argv);
2046 bprm->argc = retval;
2048 retval = count_strings_kernel(envp);
2051 bprm->envc = retval;
2053 retval = bprm_stack_limits(bprm);
2057 retval = copy_string_kernel(bprm->filename, bprm);
2060 bprm->exec = bprm->p;
2062 retval = copy_strings_kernel(bprm->envc, envp, bprm);
2066 retval = copy_strings_kernel(bprm->argc, argv, bprm);
2070 retval = bprm_execve(bprm, fd, filename, 0);
2078 static int do_execve(struct filename *filename,
2079 const char __user *const __user *__argv,
2080 const char __user *const __user *__envp)
2082 struct user_arg_ptr argv = { .ptr.native = __argv };
2083 struct user_arg_ptr envp = { .ptr.native = __envp };
2084 return do_execveat_common(AT_FDCWD, filename, argv, envp, 0);
2087 static int do_execveat(int fd, struct filename *filename,
2088 const char __user *const __user *__argv,
2089 const char __user *const __user *__envp,
2092 struct user_arg_ptr argv = { .ptr.native = __argv };
2093 struct user_arg_ptr envp = { .ptr.native = __envp };
2095 return do_execveat_common(fd, filename, argv, envp, flags);
2098 #ifdef CONFIG_COMPAT
2099 static int compat_do_execve(struct filename *filename,
2100 const compat_uptr_t __user *__argv,
2101 const compat_uptr_t __user *__envp)
2103 struct user_arg_ptr argv = {
2105 .ptr.compat = __argv,
2107 struct user_arg_ptr envp = {
2109 .ptr.compat = __envp,
2111 return do_execveat_common(AT_FDCWD, filename, argv, envp, 0);
2114 static int compat_do_execveat(int fd, struct filename *filename,
2115 const compat_uptr_t __user *__argv,
2116 const compat_uptr_t __user *__envp,
2119 struct user_arg_ptr argv = {
2121 .ptr.compat = __argv,
2123 struct user_arg_ptr envp = {
2125 .ptr.compat = __envp,
2127 return do_execveat_common(fd, filename, argv, envp, flags);
2131 void set_binfmt(struct linux_binfmt *new)
2133 struct mm_struct *mm = current->mm;
2136 module_put(mm->binfmt->module);
2140 __module_get(new->module);
2142 EXPORT_SYMBOL(set_binfmt);
2145 * set_dumpable stores three-value SUID_DUMP_* into mm->flags.
2147 void set_dumpable(struct mm_struct *mm, int value)
2149 if (WARN_ON((unsigned)value > SUID_DUMP_ROOT))
2152 set_mask_bits(&mm->flags, MMF_DUMPABLE_MASK, value);
2155 SYSCALL_DEFINE3(execve,
2156 const char __user *, filename,
2157 const char __user *const __user *, argv,
2158 const char __user *const __user *, envp)
2160 return do_execve(getname(filename), argv, envp);
2163 SYSCALL_DEFINE5(execveat,
2164 int, fd, const char __user *, filename,
2165 const char __user *const __user *, argv,
2166 const char __user *const __user *, envp,
2169 int lookup_flags = (flags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0;
2171 return do_execveat(fd,
2172 getname_flags(filename, lookup_flags, NULL),
2176 #ifdef CONFIG_COMPAT
2177 COMPAT_SYSCALL_DEFINE3(execve, const char __user *, filename,
2178 const compat_uptr_t __user *, argv,
2179 const compat_uptr_t __user *, envp)
2181 return compat_do_execve(getname(filename), argv, envp);
2184 COMPAT_SYSCALL_DEFINE5(execveat, int, fd,
2185 const char __user *, filename,
2186 const compat_uptr_t __user *, argv,
2187 const compat_uptr_t __user *, envp,
2190 int lookup_flags = (flags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0;
2192 return compat_do_execveat(fd,
2193 getname_flags(filename, lookup_flags, NULL),