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]/
Cc: Jason A. Donenfeld <[email protected]>
Cc: "Jason A. Donenfeld" <[email protected]>
Cc: Andrew Lunn <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: Paolo Abeni <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
drivers/net/wireguard/cookie.c | 4 ++--
drivers/net/wireguard/noise.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/net/wireguard/cookie.c b/drivers/net/wireguard/cookie.c
index f89581b5e8cb..94d0a7206084 100644
--- a/drivers/net/wireguard/cookie.c
+++ b/drivers/net/wireguard/cookie.c
@@ -26,8 +26,8 @@ void wg_cookie_checker_init(struct cookie_checker *checker,
}
enum { COOKIE_KEY_LABEL_LEN = 8 };
-static const u8 mac1_key_label[COOKIE_KEY_LABEL_LEN] = "mac1----";
-static const u8 cookie_key_label[COOKIE_KEY_LABEL_LEN] = "cookie--";
+static const u8 mac1_key_label[COOKIE_KEY_LABEL_LEN] __nonstring = "mac1----";
+static const u8 cookie_key_label[COOKIE_KEY_LABEL_LEN] __nonstring =
"cookie--";
static void precompute_key(u8 key[NOISE_SYMMETRIC_KEY_LEN],
const u8 pubkey[NOISE_PUBLIC_KEY_LEN],
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 [email protected]";
+static const u8 handshake_name[37] __nonstring =
"Noise_IKpsk2_25519_ChaChaPoly_BLAKE2s";
+static const u8 identifier_name[34] __nonstring = "WireGuard v1 zx2c4
[email protected]";
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
