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* [PATCH] wifi: mac80211: Write cnt before copying in ieee80211_copy_rnr_beacon()
@ 2025-07-21 18:25 Kees Cook
  2025-07-21 18:54 ` Gustavo A. R. Silva
  0 siblings, 1 reply; 2+ messages in thread
From: Kees Cook @ 2025-07-21 18:25 UTC (permalink / raw)
  To: Johannes Berg
  Cc: Kees Cook, linux-wireless, Gustavo A. R. Silva, Jeff Johnson,
	linux-kernel, linux-hardening

While I caught the need for setting cnt early in nl80211_parse_rnr_elems()
in the original annotation of struct cfg80211_rnr_elems with __counted_by,
I missed a similar pattern in ieee80211_copy_rnr_beacon(). Fix this by
moving the cnt assignment to before the loop.

Fixes: 7b6d7087031b ("wifi: cfg80211: Annotate struct cfg80211_rnr_elems with __counted_by")
Signed-off-by: Kees Cook <kees@kernel.org>
---
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: <linux-wireless@vger.kernel.org>
---
 net/mac80211/cfg.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 4f20d57ab913..2ed07fa121ab 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1176,13 +1176,13 @@ ieee80211_copy_rnr_beacon(u8 *pos, struct cfg80211_rnr_elems *dst,
 {
 	int i, offset = 0;
 
+	dst->cnt = src->cnt;
 	for (i = 0; i < src->cnt; i++) {
 		memcpy(pos + offset, src->elem[i].data, src->elem[i].len);
 		dst->elem[i].len = src->elem[i].len;
 		dst->elem[i].data = pos + offset;
 		offset += dst->elem[i].len;
 	}
-	dst->cnt = src->cnt;
 
 	return offset;
 }
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH] wifi: mac80211: Write cnt before copying in ieee80211_copy_rnr_beacon()
  2025-07-21 18:25 [PATCH] wifi: mac80211: Write cnt before copying in ieee80211_copy_rnr_beacon() Kees Cook
@ 2025-07-21 18:54 ` Gustavo A. R. Silva
  0 siblings, 0 replies; 2+ messages in thread
From: Gustavo A. R. Silva @ 2025-07-21 18:54 UTC (permalink / raw)
  To: Kees Cook, Johannes Berg
  Cc: linux-wireless, Gustavo A. R. Silva, Jeff Johnson, linux-kernel,
	linux-hardening



On 21/07/25 12:25, Kees Cook wrote:
> While I caught the need for setting cnt early in nl80211_parse_rnr_elems()
> in the original annotation of struct cfg80211_rnr_elems with __counted_by,
> I missed a similar pattern in ieee80211_copy_rnr_beacon(). Fix this by
> moving the cnt assignment to before the loop.
> 
> Fixes: 7b6d7087031b ("wifi: cfg80211: Annotate struct cfg80211_rnr_elems with __counted_by")
> Signed-off-by: Kees Cook <kees@kernel.org>

Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Thanks!
-Gustavo

> ---
> Cc: Johannes Berg <johannes@sipsolutions.net>
> Cc: <linux-wireless@vger.kernel.org>
> ---
>   net/mac80211/cfg.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
> index 4f20d57ab913..2ed07fa121ab 100644
> --- a/net/mac80211/cfg.c
> +++ b/net/mac80211/cfg.c
> @@ -1176,13 +1176,13 @@ ieee80211_copy_rnr_beacon(u8 *pos, struct cfg80211_rnr_elems *dst,
>   {
>   	int i, offset = 0;
>   
> +	dst->cnt = src->cnt;
>   	for (i = 0; i < src->cnt; i++) {
>   		memcpy(pos + offset, src->elem[i].data, src->elem[i].len);
>   		dst->elem[i].len = src->elem[i].len;
>   		dst->elem[i].data = pos + offset;
>   		offset += dst->elem[i].len;
>   	}
> -	dst->cnt = src->cnt;
>   
>   	return offset;
>   }


^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2025-07-21 18:55 UTC | newest]

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2025-07-21 18:25 [PATCH] wifi: mac80211: Write cnt before copying in ieee80211_copy_rnr_beacon() Kees Cook
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