78 static int bprm_creds_from_file(struct linux_binprm *bprm);
186 static void acct_arg_size(struct linux_binprm *bprm, unsigned long pages)  in acct_arg_size()  argument
189 	long diff = (long)(pages - bprm->vma_pages);  in acct_arg_size()
194 	bprm->vma_pages = pages;  in acct_arg_size()
198 static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,  in get_arg_page()  argument
207 		ret = expand_downwards(bprm->vma, pos);  in get_arg_page()
220 	mmap_read_lock(bprm->mm);  in get_arg_page()
221 	ret = get_user_pages_remote(bprm->mm, pos, 1, gup_flags,  in get_arg_page()
223 	mmap_read_unlock(bprm->mm);  in get_arg_page()
228 		acct_arg_size(bprm, vma_pages(bprm->vma));  in get_arg_page()
238 static void free_arg_pages(struct linux_binprm *bprm)  in free_arg_pages()  argument
242 static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos,  in flush_arg_page()  argument
245 	flush_cache_page(bprm->vma, pos, page_to_pfn(page));  in flush_arg_page()
248 static int __bprm_mm_init(struct linux_binprm *bprm)  in __bprm_mm_init()  argument
252 	struct mm_struct *mm = bprm->mm;  in __bprm_mm_init()
254 	bprm->vma = vma = vm_area_alloc(mm);  in __bprm_mm_init()
282 	bprm->p = vma->vm_end - sizeof(void *);  in __bprm_mm_init()
287 	bprm->vma = NULL;  in __bprm_mm_init()
292 static bool valid_arg_len(struct linux_binprm *bprm, long len)  in valid_arg_len()  argument
299 static inline void acct_arg_size(struct linux_binprm *bprm, unsigned long pages)  in acct_arg_size()  argument
303 static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,  in get_arg_page()  argument
308 	page = bprm->page[pos / PAGE_SIZE];  in get_arg_page()
313 		bprm->page[pos / PAGE_SIZE] = page;  in get_arg_page()
323 static void free_arg_page(struct linux_binprm *bprm, int i)  in free_arg_page()  argument
325 	if (bprm->page[i]) {  in free_arg_page()
326 		__free_page(bprm->page[i]);  in free_arg_page()
327 		bprm->page[i] = NULL;  in free_arg_page()
331 static void free_arg_pages(struct linux_binprm *bprm)  in free_arg_pages()  argument
336 		free_arg_page(bprm, i);  in free_arg_pages()
339 static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos,  in flush_arg_page()  argument
344 static int __bprm_mm_init(struct linux_binprm *bprm)  in __bprm_mm_init()  argument
346 	bprm->p = PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *);  in __bprm_mm_init()
350 static bool valid_arg_len(struct linux_binprm *bprm, long len)  in valid_arg_len()  argument
352 	return len <= bprm->p;  in valid_arg_len()
363 static int bprm_mm_init(struct linux_binprm *bprm)  in bprm_mm_init()  argument
368 	bprm->mm = mm = mm_alloc();  in bprm_mm_init()
375 	bprm->rlim_stack = current->signal->rlim[RLIMIT_STACK];  in bprm_mm_init()
378 	err = __bprm_mm_init(bprm);  in bprm_mm_init()
386 		bprm->mm = NULL;  in bprm_mm_init()
472 static int bprm_stack_limits(struct linux_binprm *bprm)  in bprm_stack_limits()  argument
485 	limit = min(limit, bprm->rlim_stack.rlim_cur / 4);  in bprm_stack_limits()
498 	ptr_size = (bprm->argc + bprm->envc) * sizeof(void *);  in bprm_stack_limits()
503 	bprm->argmin = bprm->p - limit;  in bprm_stack_limits()
513 			struct linux_binprm *bprm)  in copy_strings()  argument
535 		if (!valid_arg_len(bprm, len))  in copy_strings()
539 		pos = bprm->p;  in copy_strings()
541 		bprm->p -= len;  in copy_strings()
543 		if (bprm->p < bprm->argmin)  in copy_strings()
572 				page = get_arg_page(bprm, pos, 1);  in copy_strings()
586 				flush_arg_page(bprm, kpos, kmapped_page);  in copy_strings()
607 int copy_string_kernel(const char *arg, struct linux_binprm *bprm)  in copy_string_kernel()  argument
610 	unsigned long pos = bprm->p;  in copy_string_kernel()
614 	if (!valid_arg_len(bprm, len))  in copy_string_kernel()
619 	bprm->p -= len;  in copy_string_kernel()
620 	if (IS_ENABLED(CONFIG_MMU) && bprm->p < bprm->argmin)  in copy_string_kernel()
633 		page = get_arg_page(bprm, pos, 1);  in copy_string_kernel()
637 		flush_arg_page(bprm, pos & PAGE_MASK, page);  in copy_string_kernel()
649 			       struct linux_binprm *bprm)  in copy_strings_kernel()  argument
652 		int ret = copy_string_kernel(argv[argc], bprm);  in copy_strings_kernel()
741 int setup_arg_pages(struct linux_binprm *bprm,  in setup_arg_pages()  argument
748 	struct vm_area_struct *vma = bprm->vma;  in setup_arg_pages()
758 	stack_base = bprm->rlim_stack.rlim_max;  in setup_arg_pages()
772 	mm->arg_start = bprm->p - stack_shift;  in setup_arg_pages()
773 	bprm->p = vma->vm_end - stack_shift;  in setup_arg_pages()
784 	bprm->p -= stack_shift;  in setup_arg_pages()
785 	mm->arg_start = bprm->p;  in setup_arg_pages()
788 	if (bprm->loader)  in setup_arg_pages()
789 		bprm->loader -= stack_shift;  in setup_arg_pages()
790 	bprm->exec -= stack_shift;  in setup_arg_pages()
817 			     bprm->file);  in setup_arg_pages()
836 	rlim_stack = bprm->rlim_stack.rlim_cur & PAGE_MASK;  in setup_arg_pages()
848 	current->mm->start_stack = bprm->p;  in setup_arg_pages()
865 int transfer_args_to_stack(struct linux_binprm *bprm,  in transfer_args_to_stack()  argument
871 	stop = bprm->p >> PAGE_SHIFT;  in transfer_args_to_stack()
875 		unsigned int offset = index == stop ? bprm->p & ~PAGE_MASK : 0;  in transfer_args_to_stack()
876 		char *src = kmap(bprm->page[index]) + offset;  in transfer_args_to_stack()
880 		kunmap(bprm->page[index]);  in transfer_args_to_stack()
1238 int begin_new_exec(struct linux_binprm * bprm)  in begin_new_exec()  argument
1244 	retval = bprm_creds_from_file(bprm);  in begin_new_exec()
1251 	bprm->point_of_no_return = true;  in begin_new_exec()
1275 	retval = set_mm_exe_file(bprm->mm, bprm->file);  in begin_new_exec()
1280 	would_dump(bprm, bprm->file);  in begin_new_exec()
1281 	if (bprm->have_execfd)  in begin_new_exec()
1282 		would_dump(bprm, bprm->executable);  in begin_new_exec()
1287 	acct_arg_size(bprm, 0);  in begin_new_exec()
1288 	retval = exec_mmap(bprm->mm);  in begin_new_exec()
1292 	bprm->mm = NULL;  in begin_new_exec()
1315 	me->personality &= ~bprm->per_clear;  in begin_new_exec()
1327 	if (bprm->secureexec) {  in begin_new_exec()
1338 		if (bprm->rlim_stack.rlim_cur > _STK_LIM)  in begin_new_exec()
1339 			bprm->rlim_stack.rlim_cur = _STK_LIM;  in begin_new_exec()
1349 	if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP ||  in begin_new_exec()
1357 	__set_task_comm(me, kbasename(bprm->filename), true);  in begin_new_exec()
1364 	retval = set_cred_ucounts(bprm->cred);  in begin_new_exec()
1371 	security_bprm_committing_creds(bprm);  in begin_new_exec()
1373 	commit_creds(bprm->cred);  in begin_new_exec()
1374 	bprm->cred = NULL;  in begin_new_exec()
1389 	security_bprm_committed_creds(bprm);  in begin_new_exec()
1392 	if (bprm->have_execfd) {  in begin_new_exec()
1396 		fd_install(retval, bprm->executable);  in begin_new_exec()
1397 		bprm->executable = NULL;  in begin_new_exec()
1398 		bprm->execfd = retval;  in begin_new_exec()
1409 void would_dump(struct linux_binprm *bprm, struct file *file)  in would_dump()  argument
1415 		bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;  in would_dump()
1418 		user_ns = old = bprm->mm->user_ns;  in would_dump()
1424 			bprm->mm->user_ns = get_user_ns(user_ns);  in would_dump()
1431 void setup_new_exec(struct linux_binprm * bprm)  in setup_new_exec()  argument
1436 	arch_pick_mmap_layout(me->mm, &bprm->rlim_stack);  in setup_new_exec()
1451 void finalize_exec(struct linux_binprm *bprm)  in finalize_exec()  argument
1455 	current->signal->rlim[RLIMIT_STACK] = bprm->rlim_stack;  in finalize_exec()
1466 static int prepare_bprm_creds(struct linux_binprm *bprm)  in prepare_bprm_creds()  argument
1471 	bprm->cred = prepare_exec_creds();  in prepare_bprm_creds()
1472 	if (likely(bprm->cred))  in prepare_bprm_creds()
1479 static void free_bprm(struct linux_binprm *bprm)  in free_bprm()  argument
1481 	if (bprm->mm) {  in free_bprm()
1482 		acct_arg_size(bprm, 0);  in free_bprm()
1483 		mmput(bprm->mm);  in free_bprm()
1485 	free_arg_pages(bprm);  in free_bprm()
1486 	if (bprm->cred) {  in free_bprm()
1488 		abort_creds(bprm->cred);  in free_bprm()
1490 	if (bprm->file) {  in free_bprm()
1491 		allow_write_access(bprm->file);  in free_bprm()
1492 		fput(bprm->file);  in free_bprm()
1494 	if (bprm->executable)  in free_bprm()
1495 		fput(bprm->executable);  in free_bprm()
1497 	if (bprm->interp != bprm->filename)  in free_bprm()
1498 		kfree(bprm->interp);  in free_bprm()
1499 	kfree(bprm->fdpath);  in free_bprm()
1500 	kfree(bprm);  in free_bprm()
1505 	struct linux_binprm *bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);  in alloc_bprm()  local
1507 	if (!bprm)  in alloc_bprm()
1511 		bprm->filename = filename->name;  in alloc_bprm()
1514 			bprm->fdpath = kasprintf(GFP_KERNEL, "/dev/fd/%d", fd);  in alloc_bprm()
1516 			bprm->fdpath = kasprintf(GFP_KERNEL, "/dev/fd/%d/%s",  in alloc_bprm()
1518 		if (!bprm->fdpath)  in alloc_bprm()
1521 		bprm->filename = bprm->fdpath;  in alloc_bprm()
1523 	bprm->interp = bprm->filename;  in alloc_bprm()
1525 	retval = bprm_mm_init(bprm);  in alloc_bprm()
1528 	return bprm;  in alloc_bprm()
1531 	free_bprm(bprm);  in alloc_bprm()
1536 int bprm_change_interp(const char *interp, struct linux_binprm *bprm)  in bprm_change_interp()  argument
1539 	if (bprm->interp != bprm->filename)  in bprm_change_interp()
1540 		kfree(bprm->interp);  in bprm_change_interp()
1541 	bprm->interp = kstrdup(interp, GFP_KERNEL);  in bprm_change_interp()
1542 	if (!bprm->interp)  in bprm_change_interp()
1553 static void check_unsafe_exec(struct linux_binprm *bprm)  in check_unsafe_exec()  argument
1559 		bprm->unsafe |= LSM_UNSAFE_PTRACE;  in check_unsafe_exec()
1566 		bprm->unsafe |= LSM_UNSAFE_NO_NEW_PRIVS;  in check_unsafe_exec()
1579 		bprm->unsafe |= LSM_UNSAFE_SHARE;  in check_unsafe_exec()
1585 static void bprm_fill_uid(struct linux_binprm *bprm, struct file *file)  in bprm_fill_uid()  argument
1617 	if (!kuid_has_mapping(bprm->cred->user_ns, uid) ||  in bprm_fill_uid()
1618 		 !kgid_has_mapping(bprm->cred->user_ns, gid))  in bprm_fill_uid()
1622 		bprm->per_clear |= PER_CLEAR_ON_SETID;  in bprm_fill_uid()
1623 		bprm->cred->euid = uid;  in bprm_fill_uid()
1627 		bprm->per_clear |= PER_CLEAR_ON_SETID;  in bprm_fill_uid()
1628 		bprm->cred->egid = gid;  in bprm_fill_uid()
1635 static int bprm_creds_from_file(struct linux_binprm *bprm)  in bprm_creds_from_file()  argument
1638 	struct file *file = bprm->execfd_creds ? bprm->executable : bprm->file;  in bprm_creds_from_file()
1640 	bprm_fill_uid(bprm, file);  in bprm_creds_from_file()
1641 	return security_bprm_creds_from_file(bprm, file);  in bprm_creds_from_file()
1650 static int prepare_binprm(struct linux_binprm *bprm)  in prepare_binprm()  argument
1654 	memset(bprm->buf, 0, BINPRM_BUF_SIZE);  in prepare_binprm()
1655 	return kernel_read(bprm->file, bprm->buf, BINPRM_BUF_SIZE, &pos);  in prepare_binprm()
1663 int remove_arg_zero(struct linux_binprm *bprm)  in remove_arg_zero()  argument
1670 	if (!bprm->argc)  in remove_arg_zero()
1674 		offset = bprm->p & ~PAGE_MASK;  in remove_arg_zero()
1675 		page = get_arg_page(bprm, bprm->p, 0);  in remove_arg_zero()
1683 				offset++, bprm->p++)  in remove_arg_zero()
1690 	bprm->p++;  in remove_arg_zero()
1691 	bprm->argc--;  in remove_arg_zero()
1703 static int search_binary_handler(struct linux_binprm *bprm)  in search_binary_handler()  argument
1709 	retval = prepare_binprm(bprm);  in search_binary_handler()
1713 	retval = security_bprm_check(bprm);  in search_binary_handler()
1725 		retval = fmt->load_binary(bprm);  in search_binary_handler()
1729 		if (bprm->point_of_no_return || (retval != -ENOEXEC)) {  in search_binary_handler()
1737 		if (printable(bprm->buf[0]) && printable(bprm->buf[1]) &&  in search_binary_handler()
1738 		    printable(bprm->buf[2]) && printable(bprm->buf[3]))  in search_binary_handler()
1740 		if (request_module("binfmt-%04x", *(ushort *)(bprm->buf + 2)) < 0)  in search_binary_handler()
1749 static int exec_binprm(struct linux_binprm *bprm)  in exec_binprm()  argument
1766 		ret = search_binary_handler(bprm);  in exec_binprm()
1769 		if (!bprm->interpreter)  in exec_binprm()
1772 		exec = bprm->file;  in exec_binprm()
1773 		bprm->file = bprm->interpreter;  in exec_binprm()
1774 		bprm->interpreter = NULL;  in exec_binprm()
1777 		if (unlikely(bprm->have_execfd)) {  in exec_binprm()
1778 			if (bprm->executable) {  in exec_binprm()
1782 			bprm->executable = exec;  in exec_binprm()
1787 	audit_bprm(bprm);  in exec_binprm()
1788 	trace_sched_process_exec(current, old_pid, bprm);  in exec_binprm()
1797 static int bprm_execve(struct linux_binprm *bprm,  in bprm_execve()  argument
1803 	retval = prepare_bprm_creds(bprm);  in bprm_execve()
1807 	check_unsafe_exec(bprm);  in bprm_execve()
1817 	bprm->file = file;  in bprm_execve()
1827 	if (bprm->fdpath && get_close_on_exec(fd))  in bprm_execve()
1828 		bprm->interp_flags |= BINPRM_FLAGS_PATH_INACCESSIBLE;  in bprm_execve()
1831 	retval = security_bprm_creds_for_exec(bprm);  in bprm_execve()
1835 	retval = exec_binprm(bprm);  in bprm_execve()
1854 	if (bprm->point_of_no_return && !fatal_signal_pending(current))  in bprm_execve()
1869 	struct linux_binprm *bprm;  in do_execveat_common()  local
1891 	bprm = alloc_bprm(fd, filename);  in do_execveat_common()
1892 	if (IS_ERR(bprm)) {  in do_execveat_common()
1893 		retval = PTR_ERR(bprm);  in do_execveat_common()
1900 	bprm->argc = retval;  in do_execveat_common()
1905 	bprm->envc = retval;  in do_execveat_common()
1907 	retval = bprm_stack_limits(bprm);  in do_execveat_common()
1911 	retval = copy_string_kernel(bprm->filename, bprm);  in do_execveat_common()
1914 	bprm->exec = bprm->p;  in do_execveat_common()
1916 	retval = copy_strings(bprm->envc, envp, bprm);  in do_execveat_common()
1920 	retval = copy_strings(bprm->argc, argv, bprm);  in do_execveat_common()
1924 	retval = bprm_execve(bprm, fd, filename, flags);  in do_execveat_common()
1926 	free_bprm(bprm);  in do_execveat_common()
1937 	struct linux_binprm *bprm;  in kernel_execve()  local
1945 	bprm = alloc_bprm(fd, filename);  in kernel_execve()
1946 	if (IS_ERR(bprm)) {  in kernel_execve()
1947 		retval = PTR_ERR(bprm);  in kernel_execve()
1954 	bprm->argc = retval;  in kernel_execve()
1959 	bprm->envc = retval;  in kernel_execve()
1961 	retval = bprm_stack_limits(bprm);  in kernel_execve()
1965 	retval = copy_string_kernel(bprm->filename, bprm);  in kernel_execve()
1968 	bprm->exec = bprm->p;  in kernel_execve()
1970 	retval = copy_strings_kernel(bprm->envc, envp, bprm);  in kernel_execve()
1974 	retval = copy_strings_kernel(bprm->argc, argv, bprm);  in kernel_execve()
1978 	retval = bprm_execve(bprm, fd, filename, 0);  in kernel_execve()
1980 	free_bprm(bprm);  in kernel_execve()