[PATCH] wireguard: noise: Add __nonstring annotations for unterminated strings

From: Kees Cook
Date: Mon Mar 10 2025 - 18:23:02 EST


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 and correctly identify the char array as "not a C
string" and thereby eliminate the warning.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117178 [1]
Cc: Jason A. Donenfeld <Jason@xxxxxxxxx>
Cc: "Jason A. Donenfeld" <Jason@xxxxxxxxx>
Cc: Andrew Lunn <andrew+netdev@xxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
Cc: wireguard@xxxxxxxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <kees@xxxxxxxxxx>
---
drivers/net/wireguard/noise.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireguard/noise.c b/drivers/net/wireguard/noise.c
index 202a33af5a72..7eb9a23a3d4d 100644
--- a/drivers/net/wireguard/noise.c
+++ b/drivers/net/wireguard/noise.c
@@ -25,8 +25,8 @@
* <- e, ee, se, psk, {}
*/

-static const u8 handshake_name[37] = "Noise_IKpsk2_25519_ChaChaPoly_BLAKE2s";
-static const u8 identifier_name[34] = "WireGuard v1 zx2c4 Jason@xxxxxxxxx";
+static const u8 handshake_name[37] __nonstring = "Noise_IKpsk2_25519_ChaChaPoly_BLAKE2s";
+static const u8 identifier_name[34] __nonstring = "WireGuard v1 zx2c4 Jason@xxxxxxxxx";
static u8 handshake_init_hash[NOISE_HASH_LEN] __ro_after_init;
static u8 handshake_init_chaining_key[NOISE_HASH_LEN] __ro_after_init;
static atomic64_t keypair_counter = ATOMIC64_INIT(0);
--
2.34.1