Re: [PATCH 6.1.y] wifi: brcmfmac: fix use-after-free when rescheduling brcmf_btcoex_info work

[Arend van Spriel]

On 12/03/2026 04:14, Robert Garcia wrote:
> From: Duoming Zhou <duoming@xxxxxxxxxx>
>
> [ Upstream commit 9cb83d4be0b9b697eae93d321e0da999f9cdfcfc ]
>
> The brcmf_btcoex_detach() only shuts down the btcoex timer, if the
> flag timer_on is false. However, the brcmf_btcoex_timerfunc(), which
> runs as timer handler, sets timer_on to false. This creates critical
> race conditions:

[...]

> To resolve the race conditions, drop the conditional check and call
> timer_shutdown_sync() directly. It can deactivate the timer reliably,
> regardless of its current state. Once stopped, the timer_on state is
> then set to false.
>
> Fixes: 61730d4dfffc ("brcmfmac: support critical protocol API for DHCP")
> Acked-by: Arend van Spriel <arend.vanspriel@xxxxxxxxxxxx>
> Signed-off-by: Duoming Zhou <duoming@xxxxxxxxxx>
> Link: https://patch.msgid.link/20250822050839.4413-1-duoming@xxxxxxxxxx
> Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
> [ Keep del_timer_sync() instead of timer_shutdown_sync() here. ]
> Signed-off-by: Robert Garcia <rob_garcia@xxxxxxx>

What tree should this go to. This looks like a stable patch so probably 
it should have been CCed to stable@xxxxxxxxxxxxxxx?

Regards,
Arend