Re: [PATCH iwl] idpf: fix corrupted frames and skb leaks in singleq mode

[Eric Dumazet]

On Thu, Dec 7, 2023 at 12:58 PM Simon Horman <horms@xxxxxxxxxx> wrote:
>
> On Fri, Dec 01, 2023 at 03:38:21PM +0100, Alexander Lobakin wrote:
> > idpf_ring::skb serves only for keeping an incomplete frame between
> > several NAPI Rx polling cycles, as one cycle may end up before
> > processing the end of packet descriptor. The pointer is taken from
> > the ring onto the stack before entering the loop and gets written
> > there after the loop exits. When inside the loop, only the onstack
> > pointer is used.
> > For some reason, the logics is broken in the singleq mode, where the
> > pointer is taken from the ring each iteration. This means that if a
> > frame got fragmented into several descriptors, each fragment will have
> > its own skb, but only the last one will be passed up the stack
> > (containing garbage), leaving the rest leaked.
> > Just don't touch the ring skb field inside the polling loop, letting
> > the onstack skb pointer work as expected: build a new skb if it's the
> > first frame descriptor and attach a frag otherwise.
> >
> > Fixes: a5ab9ee0df0b ("idpf: add singleq start_xmit and napi poll")
> > Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@xxxxxxxxx>
> > Reviewed-by: Michal Kubiak <michal.kubiak@xxxxxxxxx>
> > Signed-off-by: Alexander Lobakin <aleksander.lobakin@xxxxxxxxx>
>
> Reviewed-by: Simon Horman <horms@xxxxxxxxxx>

It seems singlequeue mode is not really used on idpf :)

Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>