Commit bbf3c7ff authored by Justin Stitt's avatar Justin Stitt Committed by Kees Cook
Browse files

lib/string_helpers: rework overflow-dependent code 



When @size is 0, the desired behavior is to allow unlimited bytes to be
parsed. Currently, this relies on some intentional arithmetic overflow
where --size gives us SIZE_MAX when size is 0.

Explicitly spell out the desired behavior without relying on intentional
overflow/underflow.

Signed-off-by: default avatarJustin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20240808-b4-string_helpers_caa133-v1-1-686a455167c4@google.com


Signed-off-by: default avatarKees Cook <kees@kernel.org>
parent 0336f898

lib/string_helpers.c

+3 −0
Original line number Diff line number Diff line
@@ -321,6 +321,9 @@ int string_unescape(char *src, char *dst, size_t size, unsigned int flags) 
{

	char *out = dst;



	if (!size)

		size = SIZE_MAX;



	while (*src && --size) {

		if (src[0] == '\\' && src[1] != '\0' && size > 1) {

			src++;