77 static int bprm_creds_from_file(struct linux_binprm *bprm);
185 static void acct_arg_size(struct linux_binprm *bprm, unsigned long pages)  in acct_arg_size()  argument
188 	long diff = (long)(pages - bprm->vma_pages);  in acct_arg_size()
193 	bprm->vma_pages = pages;  in acct_arg_size()
197 static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,  in get_arg_page()  argument
206 		ret = expand_downwards(bprm->vma, pos);  in get_arg_page()
219 	mmap_read_lock(bprm->mm);  in get_arg_page()
220 	ret = get_user_pages_remote(bprm->mm, pos, 1, gup_flags,  in get_arg_page()
222 	mmap_read_unlock(bprm->mm);  in get_arg_page()
227 		acct_arg_size(bprm, vma_pages(bprm->vma));  in get_arg_page()
237 static void free_arg_pages(struct linux_binprm *bprm)  in free_arg_pages()  argument
241 static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos,  in flush_arg_page()  argument
244 	flush_cache_page(bprm->vma, pos, page_to_pfn(page));  in flush_arg_page()
247 static int __bprm_mm_init(struct linux_binprm *bprm)  in __bprm_mm_init()  argument
251 	struct mm_struct *mm = bprm->mm;  in __bprm_mm_init()
253 	bprm->vma = vma = vm_area_alloc(mm);  in __bprm_mm_init()
281 	bprm->p = vma->vm_end - sizeof(void *);  in __bprm_mm_init()
286 	bprm->vma = NULL;  in __bprm_mm_init()
291 static bool valid_arg_len(struct linux_binprm *bprm, long len)  in valid_arg_len()  argument
298 static inline void acct_arg_size(struct linux_binprm *bprm, unsigned long pages)  in acct_arg_size()  argument
302 static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,  in get_arg_page()  argument
307 	page = bprm->page[pos / PAGE_SIZE];  in get_arg_page()
312 		bprm->page[pos / PAGE_SIZE] = page;  in get_arg_page()
322 static void free_arg_page(struct linux_binprm *bprm, int i)  in free_arg_page()  argument
324 	if (bprm->page[i]) {  in free_arg_page()
325 		__free_page(bprm->page[i]);  in free_arg_page()
326 		bprm->page[i] = NULL;  in free_arg_page()
330 static void free_arg_pages(struct linux_binprm *bprm)  in free_arg_pages()  argument
335 		free_arg_page(bprm, i);  in free_arg_pages()
338 static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos,  in flush_arg_page()  argument
343 static int __bprm_mm_init(struct linux_binprm *bprm)  in __bprm_mm_init()  argument
345 	bprm->p = PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *);  in __bprm_mm_init()
349 static bool valid_arg_len(struct linux_binprm *bprm, long len)  in valid_arg_len()  argument
351 	return len <= bprm->p;  in valid_arg_len()
362 static int bprm_mm_init(struct linux_binprm *bprm)  in bprm_mm_init()  argument
367 	bprm->mm = mm = mm_alloc();  in bprm_mm_init()
374 	bprm->rlim_stack = current->signal->rlim[RLIMIT_STACK];  in bprm_mm_init()
377 	err = __bprm_mm_init(bprm);  in bprm_mm_init()
385 		bprm->mm = NULL;  in bprm_mm_init()
471 static int bprm_stack_limits(struct linux_binprm *bprm)  in bprm_stack_limits()  argument
484 	limit = min(limit, bprm->rlim_stack.rlim_cur / 4);  in bprm_stack_limits()
503 	ptr_size = (max(bprm->argc, 1) + bprm->envc) * sizeof(void *);  in bprm_stack_limits()
508 	bprm->argmin = bprm->p - limit;  in bprm_stack_limits()
518 			struct linux_binprm *bprm)  in copy_strings()  argument
540 		if (!valid_arg_len(bprm, len))  in copy_strings()
544 		pos = bprm->p;  in copy_strings()
546 		bprm->p -= len;  in copy_strings()
548 		if (bprm->p < bprm->argmin)  in copy_strings()
577 				page = get_arg_page(bprm, pos, 1);  in copy_strings()
591 				flush_arg_page(bprm, kpos, kmapped_page);  in copy_strings()
612 int copy_string_kernel(const char *arg, struct linux_binprm *bprm)  in copy_string_kernel()  argument
615 	unsigned long pos = bprm->p;  in copy_string_kernel()
619 	if (!valid_arg_len(bprm, len))  in copy_string_kernel()
624 	bprm->p -= len;  in copy_string_kernel()
625 	if (IS_ENABLED(CONFIG_MMU) && bprm->p < bprm->argmin)  in copy_string_kernel()
637 		page = get_arg_page(bprm, pos, 1);  in copy_string_kernel()
640 		flush_arg_page(bprm, pos & PAGE_MASK, page);  in copy_string_kernel()
650 			       struct linux_binprm *bprm)  in copy_strings_kernel()  argument
653 		int ret = copy_string_kernel(argv[argc], bprm);  in copy_strings_kernel()
745 int setup_arg_pages(struct linux_binprm *bprm,  in setup_arg_pages()  argument
752 	struct vm_area_struct *vma = bprm->vma;  in setup_arg_pages()
763 	stack_base = bprm->rlim_stack.rlim_max;  in setup_arg_pages()
777 	mm->arg_start = bprm->p - stack_shift;  in setup_arg_pages()
778 	bprm->p = vma->vm_end - stack_shift;  in setup_arg_pages()
789 	bprm->p -= stack_shift;  in setup_arg_pages()
790 	mm->arg_start = bprm->p;  in setup_arg_pages()
793 	if (bprm->loader)  in setup_arg_pages()
794 		bprm->loader -= stack_shift;  in setup_arg_pages()
795 	bprm->exec -= stack_shift;  in setup_arg_pages()
825 			     bprm->file);  in setup_arg_pages()
844 	rlim_stack = bprm->rlim_stack.rlim_cur & PAGE_MASK;  in setup_arg_pages()
856 	current->mm->start_stack = bprm->p;  in setup_arg_pages()
873 int transfer_args_to_stack(struct linux_binprm *bprm,  in transfer_args_to_stack()  argument
879 	stop = bprm->p >> PAGE_SHIFT;  in transfer_args_to_stack()
883 		unsigned int offset = index == stop ? bprm->p & ~PAGE_MASK : 0;  in transfer_args_to_stack()
884 		char *src = kmap_local_page(bprm->page[index]) + offset;  in transfer_args_to_stack()
1244 int begin_new_exec(struct linux_binprm * bprm)  in begin_new_exec()  argument
1250 	retval = bprm_creds_from_file(bprm);  in begin_new_exec()
1257 	bprm->point_of_no_return = true;  in begin_new_exec()
1281 	retval = set_mm_exe_file(bprm->mm, bprm->file);  in begin_new_exec()
1286 	would_dump(bprm, bprm->file);  in begin_new_exec()
1287 	if (bprm->have_execfd)  in begin_new_exec()
1288 		would_dump(bprm, bprm->executable);  in begin_new_exec()
1293 	acct_arg_size(bprm, 0);  in begin_new_exec()
1294 	retval = exec_mmap(bprm->mm);  in begin_new_exec()
1298 	bprm->mm = NULL;  in begin_new_exec()
1318 	me->personality &= ~bprm->per_clear;  in begin_new_exec()
1330 	if (bprm->secureexec) {  in begin_new_exec()
1341 		if (bprm->rlim_stack.rlim_cur > _STK_LIM)  in begin_new_exec()
1342 			bprm->rlim_stack.rlim_cur = _STK_LIM;  in begin_new_exec()
1352 	if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP ||  in begin_new_exec()
1360 	__set_task_comm(me, kbasename(bprm->filename), true);  in begin_new_exec()
1367 	retval = set_cred_ucounts(bprm->cred);  in begin_new_exec()
1374 	security_bprm_committing_creds(bprm);  in begin_new_exec()
1376 	commit_creds(bprm->cred);  in begin_new_exec()
1377 	bprm->cred = NULL;  in begin_new_exec()
1392 	security_bprm_committed_creds(bprm);  in begin_new_exec()
1395 	if (bprm->have_execfd) {  in begin_new_exec()
1399 		fd_install(retval, bprm->executable);  in begin_new_exec()
1400 		bprm->executable = NULL;  in begin_new_exec()
1401 		bprm->execfd = retval;  in begin_new_exec()
1412 void would_dump(struct linux_binprm *bprm, struct file *file)  in would_dump()  argument
1418 		bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;  in would_dump()
1421 		user_ns = old = bprm->mm->user_ns;  in would_dump()
1427 			bprm->mm->user_ns = get_user_ns(user_ns);  in would_dump()
1434 void setup_new_exec(struct linux_binprm * bprm)  in setup_new_exec()  argument
1439 	arch_pick_mmap_layout(me->mm, &bprm->rlim_stack);  in setup_new_exec()
1454 void finalize_exec(struct linux_binprm *bprm)  in finalize_exec()  argument
1458 	current->signal->rlim[RLIMIT_STACK] = bprm->rlim_stack;  in finalize_exec()
1469 static int prepare_bprm_creds(struct linux_binprm *bprm)  in prepare_bprm_creds()  argument
1474 	bprm->cred = prepare_exec_creds();  in prepare_bprm_creds()
1475 	if (likely(bprm->cred))  in prepare_bprm_creds()
1482 static void free_bprm(struct linux_binprm *bprm)  in free_bprm()  argument
1484 	if (bprm->mm) {  in free_bprm()
1485 		acct_arg_size(bprm, 0);  in free_bprm()
1486 		mmput(bprm->mm);  in free_bprm()
1488 	free_arg_pages(bprm);  in free_bprm()
1489 	if (bprm->cred) {  in free_bprm()
1491 		abort_creds(bprm->cred);  in free_bprm()
1493 	if (bprm->file) {  in free_bprm()
1494 		allow_write_access(bprm->file);  in free_bprm()
1495 		fput(bprm->file);  in free_bprm()
1497 	if (bprm->executable)  in free_bprm()
1498 		fput(bprm->executable);  in free_bprm()
1500 	if (bprm->interp != bprm->filename)  in free_bprm()
1501 		kfree(bprm->interp);  in free_bprm()
1502 	kfree(bprm->fdpath);  in free_bprm()
1503 	kfree(bprm);  in free_bprm()
1508 	struct linux_binprm *bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);  in alloc_bprm()  local
1510 	if (!bprm)  in alloc_bprm()
1514 		bprm->filename = filename->name;  in alloc_bprm()
1517 			bprm->fdpath = kasprintf(GFP_KERNEL, "/dev/fd/%d", fd);  in alloc_bprm()
1519 			bprm->fdpath = kasprintf(GFP_KERNEL, "/dev/fd/%d/%s",  in alloc_bprm()
1521 		if (!bprm->fdpath)  in alloc_bprm()
1524 		bprm->filename = bprm->fdpath;  in alloc_bprm()
1526 	bprm->interp = bprm->filename;  in alloc_bprm()
1528 	retval = bprm_mm_init(bprm);  in alloc_bprm()
1531 	return bprm;  in alloc_bprm()
1534 	free_bprm(bprm);  in alloc_bprm()
1539 int bprm_change_interp(const char *interp, struct linux_binprm *bprm)  in bprm_change_interp()  argument
1542 	if (bprm->interp != bprm->filename)  in bprm_change_interp()
1543 		kfree(bprm->interp);  in bprm_change_interp()
1544 	bprm->interp = kstrdup(interp, GFP_KERNEL);  in bprm_change_interp()
1545 	if (!bprm->interp)  in bprm_change_interp()
1556 static void check_unsafe_exec(struct linux_binprm *bprm)  in check_unsafe_exec()  argument
1562 		bprm->unsafe |= LSM_UNSAFE_PTRACE;  in check_unsafe_exec()
1569 		bprm->unsafe |= LSM_UNSAFE_NO_NEW_PRIVS;  in check_unsafe_exec()
1582 		bprm->unsafe |= LSM_UNSAFE_SHARE;  in check_unsafe_exec()
1588 static void bprm_fill_uid(struct linux_binprm *bprm, struct file *file)  in bprm_fill_uid()  argument
1619 	if (!kuid_has_mapping(bprm->cred->user_ns, uid) ||  in bprm_fill_uid()
1620 		 !kgid_has_mapping(bprm->cred->user_ns, gid))  in bprm_fill_uid()
1624 		bprm->per_clear |= PER_CLEAR_ON_SETID;  in bprm_fill_uid()
1625 		bprm->cred->euid = uid;  in bprm_fill_uid()
1629 		bprm->per_clear |= PER_CLEAR_ON_SETID;  in bprm_fill_uid()
1630 		bprm->cred->egid = gid;  in bprm_fill_uid()
1637 static int bprm_creds_from_file(struct linux_binprm *bprm)  in bprm_creds_from_file()  argument
1640 	struct file *file = bprm->execfd_creds ? bprm->executable : bprm->file;  in bprm_creds_from_file()
1642 	bprm_fill_uid(bprm, file);  in bprm_creds_from_file()
1643 	return security_bprm_creds_from_file(bprm, file);  in bprm_creds_from_file()
1652 static int prepare_binprm(struct linux_binprm *bprm)  in prepare_binprm()  argument
1656 	memset(bprm->buf, 0, BINPRM_BUF_SIZE);  in prepare_binprm()
1657 	return kernel_read(bprm->file, bprm->buf, BINPRM_BUF_SIZE, &pos);  in prepare_binprm()
1665 int remove_arg_zero(struct linux_binprm *bprm)  in remove_arg_zero()  argument
1672 	if (!bprm->argc)  in remove_arg_zero()
1676 		offset = bprm->p & ~PAGE_MASK;  in remove_arg_zero()
1677 		page = get_arg_page(bprm, bprm->p, 0);  in remove_arg_zero()
1685 				offset++, bprm->p++)  in remove_arg_zero()
1692 	bprm->p++;  in remove_arg_zero()
1693 	bprm->argc--;  in remove_arg_zero()
1705 static int search_binary_handler(struct linux_binprm *bprm)  in search_binary_handler()  argument
1711 	retval = prepare_binprm(bprm);  in search_binary_handler()
1715 	retval = security_bprm_check(bprm);  in search_binary_handler()
1727 		retval = fmt->load_binary(bprm);  in search_binary_handler()
1731 		if (bprm->point_of_no_return || (retval != -ENOEXEC)) {  in search_binary_handler()
1739 		if (printable(bprm->buf[0]) && printable(bprm->buf[1]) &&  in search_binary_handler()
1740 		    printable(bprm->buf[2]) && printable(bprm->buf[3]))  in search_binary_handler()
1742 		if (request_module("binfmt-%04x", *(ushort *)(bprm->buf + 2)) < 0)  in search_binary_handler()
1751 static int exec_binprm(struct linux_binprm *bprm)  in exec_binprm()  argument
1768 		ret = search_binary_handler(bprm);  in exec_binprm()
1771 		if (!bprm->interpreter)  in exec_binprm()
1774 		exec = bprm->file;  in exec_binprm()
1775 		bprm->file = bprm->interpreter;  in exec_binprm()
1776 		bprm->interpreter = NULL;  in exec_binprm()
1779 		if (unlikely(bprm->have_execfd)) {  in exec_binprm()
1780 			if (bprm->executable) {  in exec_binprm()
1784 			bprm->executable = exec;  in exec_binprm()
1789 	audit_bprm(bprm);  in exec_binprm()
1790 	trace_sched_process_exec(current, old_pid, bprm);  in exec_binprm()
1799 static int bprm_execve(struct linux_binprm *bprm,  in bprm_execve()  argument
1805 	retval = prepare_bprm_creds(bprm);  in bprm_execve()
1809 	check_unsafe_exec(bprm);  in bprm_execve()
1819 	bprm->file = file;  in bprm_execve()
1829 	if (bprm->fdpath && get_close_on_exec(fd))  in bprm_execve()
1830 		bprm->interp_flags |= BINPRM_FLAGS_PATH_INACCESSIBLE;  in bprm_execve()
1833 	retval = security_bprm_creds_for_exec(bprm);  in bprm_execve()
1837 	retval = exec_binprm(bprm);  in bprm_execve()
1856 	if (bprm->point_of_no_return && !fatal_signal_pending(current))  in bprm_execve()
1871 	struct linux_binprm *bprm;  in do_execveat_common()  local
1893 	bprm = alloc_bprm(fd, filename);  in do_execveat_common()
1894 	if (IS_ERR(bprm)) {  in do_execveat_common()
1895 		retval = PTR_ERR(bprm);  in do_execveat_common()
1902 			     current->comm, bprm->filename);  in do_execveat_common()
1905 	bprm->argc = retval;  in do_execveat_common()
1910 	bprm->envc = retval;  in do_execveat_common()
1912 	retval = bprm_stack_limits(bprm);  in do_execveat_common()
1916 	retval = copy_string_kernel(bprm->filename, bprm);  in do_execveat_common()
1919 	bprm->exec = bprm->p;  in do_execveat_common()
1921 	retval = copy_strings(bprm->envc, envp, bprm);  in do_execveat_common()
1925 	retval = copy_strings(bprm->argc, argv, bprm);  in do_execveat_common()
1935 	if (bprm->argc == 0) {  in do_execveat_common()
1936 		retval = copy_string_kernel("", bprm);  in do_execveat_common()
1939 		bprm->argc = 1;  in do_execveat_common()
1942 	retval = bprm_execve(bprm, fd, filename, flags);  in do_execveat_common()
1944 	free_bprm(bprm);  in do_execveat_common()
1955 	struct linux_binprm *bprm;  in kernel_execve()  local
1967 	bprm = alloc_bprm(fd, filename);  in kernel_execve()
1968 	if (IS_ERR(bprm)) {  in kernel_execve()
1969 		retval = PTR_ERR(bprm);  in kernel_execve()
1978 	bprm->argc = retval;  in kernel_execve()
1983 	bprm->envc = retval;  in kernel_execve()
1985 	retval = bprm_stack_limits(bprm);  in kernel_execve()
1989 	retval = copy_string_kernel(bprm->filename, bprm);  in kernel_execve()
1992 	bprm->exec = bprm->p;  in kernel_execve()
1994 	retval = copy_strings_kernel(bprm->envc, envp, bprm);  in kernel_execve()
1998 	retval = copy_strings_kernel(bprm->argc, argv, bprm);  in kernel_execve()
2002 	retval = bprm_execve(bprm, fd, filename, 0);  in kernel_execve()
2004 	free_bprm(bprm);  in kernel_execve()