On Wed, Mar 12, 2025 at 01:14:51PM -0700, Kees Cook wrote: > When a character array without a terminating NUL character has a static > initializer, GCC 15's -Wunterminated-string-initialization will only > warn if the array lacks the "nonstring" attribute[1]. Mark the arrays > with __nonstring to correctly identify the char array as "not a C string" > and thereby eliminate the warning: > > ../drivers/net/wireguard/cookie.c:29:56: warning: initializer-string for > array of 'unsigned char' truncates NUL terminator but destination lacks > 'nonstring' attribute (9 chars into 8 available) > [-Wunterminated-string-initialization] > 29 | static const u8 mac1_key_label[COOKIE_KEY_LABEL_LEN] = "mac1----"; > | ^~~~~~~~~~ > ../drivers/net/wireguard/cookie.c:30:58: warning: initializer-string for > array of 'unsigned char' truncates NUL terminator but destination lacks > 'nonstring' attribute (9 chars into 8 available) > [-Wunterminated-string-initialization] > 30 | static const u8 cookie_key_label[COOKIE_KEY_LABEL_LEN] = "cookie--"; > | ^~~~~~~~~~ > ../drivers/net/wireguard/noise.c:28:38: warning: initializer-string for array > of 'unsigned char' truncates NUL terminator but destination lacks 'nonstring' > attribute (38 chars into 37 available) [-Wunterminated-string-initialization] > 28 | static const u8 handshake_name[37] = > "Noise_IKpsk2_25519_ChaChaPoly_BLAKE2s"; > | > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > ../drivers/net/wireguard/noise.c:29:39: warning: initializer-string for array > of 'unsigned char' truncates NUL terminator but destination lacks 'nonstring' > attribute (35 chars into 34 available) [-Wunterminated-string-initialization] > 29 | static const u8 identifier_name[34] = "WireGuard v1 zx2c4 > [email protected]"; > | > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > The arrays are always used with their fixed size, so use __nonstring. > > Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117178 [1] > Signed-off-by: Kees Cook <[email protected]> > --- > v2: Improve commit log, add cookie nonstrings too > v1: https://lore.kernel.org/lkml/[email protected]/
Reviewed-by: Simon Horman <[email protected]>
