On 06/07/2018 09:06 AM, gree...@candelatech.com wrote:
> From: Ben Greear <gree...@candelatech.com>
>
> While testing an ath10k firmware that often crashed under load,
> I was seeing kernel crashes as well. One of them appeared to
> be a dereference of a NULL flow object in fq_tin_dequeue.
>
> I have since fixed the firmware flaw, but I think it would be
> worth adding the WARN_ON in case the problem appears again.
>
> common_interrupt+0xf/0xf
> </IRQ>
>
Please find the exact commit that brought this bug,
and add a corresponding Fixes: tag
> Signed-off-by: Ben Greear <gree...@candelatech.com>
> ---
> include/net/fq_impl.h | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/include/net/fq_impl.h b/include/net/fq_impl.h
> index be7c0fa..e40354d 100644
> --- a/include/net/fq_impl.h
> +++ b/include/net/fq_impl.h
> @@ -80,6 +80,9 @@ static struct sk_buff *fq_tin_dequeue(struct fq *fq,
>
> flow = list_first_entry(head, struct fq_flow, flowchain);
>
> + if (WARN_ON_ONCE(!flow))
> + return NULL;
> +
> if (flow->deficit <= 0) {
> flow->deficit += fq->quantum;
> list_move_tail(&flow->flowchain,
>
