Re: [PATCH wireless] wifi: brcmfmac: validate msgbuf flowring IDs before use

[Arend van Spriel <arend.vanspriel@broadcom.com>]

On 02/08/2026 10:39, Arend van Spriel wrote:
> On Thu, 23 Jul 2026 13:56:17 +0800, Can Peng <pengcan@kylinos.cn> wrote:
>> Firmware messages carry flow_ring_id values which brcmfmac converts
>> to an internal flowid by subtracting
>> BRCMF_H2D_MSGRING_FLOWRING_IDSTART. The resulting value is used as
>> a bit index in txstatus_done_map and as an array index into
>> msgbuf->flowrings and the flowring state.
>>
>> Validate the firmware supplied flow_ring_id before using it. This
>> prevents flow_ring_id values below BRCMF_H2D_MSGRING_FLOWRING_IDSTART
>> from underflowing and rejects values outside msgbuf->max_flowrings.
>>
>> In the tx status path, complete the packet with an error after
>> removing a valid packet id so the skb is not leaked when the flow
>> ring id is invalid.
>>
>> Fixes: 9a1bb60250d2 ("brcmfmac: Adding msgbuf protocol.")
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Can Peng <pengcan@kylinos.cn>
>> ---
>>   .../wireless/broadcom/brcm80211/brcmfmac/msgbuf.c  | 46 +++++++++++++++++++---
>>   1 file changed, 40 insertions(+), 6 deletions(-)
> 
> One nit: there is a double blank line between brcmf_msgbuf_get_flowid()
> and brcmf_msgbuf_dequeue_work() in the resulting code. This comes from
> the pre-existing double blank line that was between
> brcmf_msgbuf_remove_flowring() and brcmf_msgbuf_dequeue_work() -- worth
> cleaning up to a single blank line.
> 
> Minor enough that I will take care of it while applying if you do not
> send a v2.

As I do not apply anything anywhere maybe Johannes will, but feel free 
to send that v2.

Regards,
Arend