generic: net: add pending wireguard patch to fix build with GCC15

This patch adds __nonstring annotation to address GCC15 with
-Wunterminated-string-initialization.
It is accepted in wireguard-linux in [1] and pending for v6.16
in [2].

[1] https://git.zx2c4.com/wireguard-linux/commit/?h=devel&id=71e5da46e78c1cd24e2feed251a2845327447ad8
[2] https://patch.msgid.link/[email protected]

Signed-off-by: Jonas Jelonek <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/18950
Signed-off-by: Hauke Mehrtens <[email protected]>

target/linux/generic/pending-6.12/152-net-wireguard-add-nonstring-annotation-to-fix-build-with-GCC15.patch

@@ -0,0 +1,63 @@
+From 71e5da46e78c1cd24e2feed251a2845327447ad8 Mon Sep 17 00:00:00 2001
+From: Kees Cook <[email protected]>
+Date: Wed, 21 May 2025 23:27:04 +0200
+Subject: wireguard: global: add __nonstring annotations for unterminated
+ strings
+
+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]>
+Signed-off-by: Jason A. Donenfeld <[email protected]>
+Link: https://patch.msgid.link/[email protected]
+Signed-off-by: Paolo Abeni <[email protected]>
+---
+ drivers/net/wireguard/cookie.c | 4 ++--
+ drivers/net/wireguard/noise.c  | 4 ++--
+ 2 files changed, 4 insertions(+), 4 deletions(-)
+
+--- a/drivers/net/wireguard/cookie.c
++++ b/drivers/net/wireguard/cookie.c
+@@ -26,8 +26,8 @@ void wg_cookie_checker_init(struct cooki
+ }
+ 
+ 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],
+--- 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);

target/linux/generic/pending-6.6/152-net-wireguard-add-nonstring-annotation-to-fix-build-with-GCC15.patch

@@ -0,0 +1,63 @@
+From 71e5da46e78c1cd24e2feed251a2845327447ad8 Mon Sep 17 00:00:00 2001
+From: Kees Cook <[email protected]>
+Date: Wed, 21 May 2025 23:27:04 +0200
+Subject: wireguard: global: add __nonstring annotations for unterminated
+ strings
+
+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]>
+Signed-off-by: Jason A. Donenfeld <[email protected]>
+Link: https://patch.msgid.link/[email protected]
+Signed-off-by: Paolo Abeni <[email protected]>
+---
+ drivers/net/wireguard/cookie.c | 4 ++--
+ drivers/net/wireguard/noise.c  | 4 ++--
+ 2 files changed, 4 insertions(+), 4 deletions(-)
+
+--- a/drivers/net/wireguard/cookie.c
++++ b/drivers/net/wireguard/cookie.c
+@@ -26,8 +26,8 @@ void wg_cookie_checker_init(struct cooki
+ }
+ 
+ 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],
+--- 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);