[PATCH] wifi: mac80211: Add __nonstring annotations for unterminated strings

[PATCH] wifi: mac80211: Add __nonstring annotations for unterminated strings

[Kees Cook]

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: Andrew Lunn <andrew+netdev@lunn.ch>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Kalle Valo <kvalo@kernel.org>
Cc: Julia Lawall <Julia.Lawall@inria.fr>
Cc: En-Wei Wu <en-wei.wu@canonical.com>
Cc: Shaul Triebitz <shaul.triebitz@intel.com>
Cc: Alexander Wetzel <alexander@wetzel-home.de>
Cc: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
---
 drivers/net/wireless/virtual/virt_wifi.c     | 2 +-
 drivers/net/wireless/zydas/zd1211rw/zd_mac.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/virtual/virt_wifi.c b/drivers/net/wireless/virtual/virt_wifi.c
index 4ee374080466..fc122b79301a 100644
--- a/drivers/net/wireless/virtual/virt_wifi.c
+++ b/drivers/net/wireless/virtual/virt_wifi.c
@@ -146,7 +146,7 @@ static void virt_wifi_inform_bss(struct wiphy *wiphy)
 	static const struct {
 		u8 tag;
 		u8 len;
-		u8 ssid[8];
+		u8 ssid[8] __nonstring;
 	} __packed ssid = {
 		.tag = WLAN_EID_SSID,
 		.len = VIRT_WIFI_SSID_LEN,
diff --git a/drivers/net/wireless/zydas/zd1211rw/zd_mac.c b/drivers/net/wireless/zydas/zd1211rw/zd_mac.c
index f90c33d19b39..9653dbaac3c0 100644
--- a/drivers/net/wireless/zydas/zd1211rw/zd_mac.c
+++ b/drivers/net/wireless/zydas/zd1211rw/zd_mac.c
@@ -21,7 +21,7 @@
 
 struct zd_reg_alpha2_map {
 	u32 reg;
-	char alpha2[2];
+	char alpha2[2] __nonstring;
 };
 
 static struct zd_reg_alpha2_map reg_alpha2_map[] = {
-- 
2.34.1

Re: [PATCH] wifi: mac80211: Add __nonstring annotations for unterminated strings

[Johannes Berg]

On Mon, 2025-03-10 at 15:23 -0700, Kees Cook wrote:
> 
>  drivers/net/wireless/virtual/virt_wifi.c     | 2 +-
>  drivers/net/wireless/zydas/zd1211rw/zd_mac.c | 2 +-
> 

That's not mac80211?

Also, I have no idea how you came up with the CC list but it seems
excessive. :)

johannes

Re: [PATCH] wifi: mac80211: Add __nonstring annotations for unterminated strings

[Kees Cook]

On Tue, Mar 11, 2025 at 10:25:10AM +0100, Johannes Berg wrote:
> On Mon, 2025-03-10 at 15:23 -0700, Kees Cook wrote:
> > 
> >  drivers/net/wireless/virtual/virt_wifi.c     | 2 +-
> >  drivers/net/wireless/zydas/zd1211rw/zd_mac.c | 2 +-
> > 
> 
> That's not mac80211?

Hrm, you're right. The automation I use for splitting up "treewide"
changes per subsystem tries to guess at a reasonable subject give a set
of files, based on historical git subject prefixes. And these two files
ended up grouped together because no more specific subsystem claimed
them.

It seems I should probably split this into two, as:

wifi: zd1211rw:
wifi: virt_wifi:

> Also, I have no idea how you came up with the CC list but it seems
> excessive. :)

It's based on my permutation of arguments to get_maintainers.pl that
seems to work best for splitting my "treewide" changes per subsystem:

        ccs = subprocess.run(["./scripts/get_maintainer.pl", "--email",
                              "--git-min-percent", "15",
                              "--git-since", '3-years-ago',
                              "--no-rolestats", patch.name],

-Kees

-- 
Kees Cook