ieee80211_invoke_fast_rx() is documented as safe for parallel RX, but
its per-invocation rx_result is declared static. Concurrent callers then
share one instance and can overwrite each other's result between
ieee80211_rx_mesh_data() and the switch on res.

That can make a packet that was queued or consumed by
ieee80211_rx_mesh_data() fall through into ieee80211_rx_8023(), or make
a packet that should continue return as queued.

Make res an automatic variable so each invocation keeps its own result.

Fixes: 3468e1e0c639 ("wifi: mac80211: add mesh fast-rx support")
Cc: stable@vger.kernel.org
Signed-off-by: Catherine <enderaoelyther@gmail.com>
---
 net/mac80211/rx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 3e5d1c47a..8719db8f3 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -4971,7 +4971,7 @@ static bool ieee80211_invoke_fast_rx(struct ieee80211_rx_data *rx,
 	struct sk_buff *skb = rx->skb;
 	struct ieee80211_hdr *hdr = (void *)skb->data;
 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
-	static ieee80211_rx_result res;
+	ieee80211_rx_result res;
 	int orig_len = skb->len;
 	int hdrlen = ieee80211_hdrlen(hdr->frame_control);
 	int snap_offs = hdrlen;
-- 
2.50.1 (Apple Git-155)

On 4/24/2026 6:14 AM, Catherine wrote:
> ieee80211_invoke_fast_rx() is documented as safe for parallel RX, but
> its per-invocation rx_result is declared static. Concurrent callers then
> share one instance and can overwrite each other's result between
> ieee80211_rx_mesh_data() and the switch on res.
> 
> That can make a packet that was queued or consumed by
> ieee80211_rx_mesh_data() fall through into ieee80211_rx_8023(), or make
> a packet that should continue return as queued.
> 
> Make res an automatic variable so each invocation keeps its own result.
> 
> Fixes: 3468e1e0c639 ("wifi: mac80211: add mesh fast-rx support")

@Felix: Any recollection why this was static in your original patch?

> Cc: stable@vger.kernel.org
> Signed-off-by: Catherine <enderaoelyther@gmail.com>

Is this an identity you commonly use? Note that anonymous contributions are
not allowed:

https://www.kernel.org/doc/html/latest/process/submitting-patches.html#developer-s-certificate-of-origin-1-1

> ---
>  net/mac80211/rx.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
> index 3e5d1c47a..8719db8f3 100644
> --- a/net/mac80211/rx.c
> +++ b/net/mac80211/rx.c
> @@ -4971,7 +4971,7 @@ static bool ieee80211_invoke_fast_rx(struct ieee80211_rx_data *rx,
>  	struct sk_buff *skb = rx->skb;
>  	struct ieee80211_hdr *hdr = (void *)skb->data;
>  	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
> -	static ieee80211_rx_result res;
> +	ieee80211_rx_result res;
>  	int orig_len = skb->len;
>  	int hdrlen = ieee80211_hdrlen(hdr->frame_control);
>  	int snap_offs = hdrlen;

Actual patch seem reasonable..

Reviewed-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>

On Tue, Apr 28, 2026 at 07:23:30AM -0700, Jeff Johnson wrote:
> Is this an identity you commonly use? Note that anonymous
> contributions are not allowed:
>
> https://www.kernel.org/doc/html/latest/process/submitting-patches.html#developer-s-certificate-of-origin-1-1

Apologies for the truncated From line.  My full name is Zhao Li; I
sign other kernel contributions the same way.  For DCO purposes,
please treat this patch as:

Signed-off-by: Zhao Li <enderaoelyther@gmail.com>

I will use the full name on resends and follow-up patches.  Thanks
for the review.

--
Zhao Li