Messages in this thread | | | Date | Thu, 7 Dec 2023 15:27:13 +0100 | Subject | Re: [PATCH iwl] idpf: fix corrupted frames and skb leaks in singleq mode | From | Alexander Lobakin <> |
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From: Eric Dumazet <edumazet@google.com> Date: Thu, 7 Dec 2023 13:48:52 +0100
> On Thu, Dec 7, 2023 at 12:58 PM Simon Horman <horms@kernel.org> 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@intel.com> >>> Reviewed-by: Michal Kubiak <michal.kubiak@intel.com> >>> Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> >> >> Reviewed-by: Simon Horman <horms@kernel.org> > > It seems singlequeue mode is not really used on idpf :)
From what I know, there's currently no hardware supporting singleq mode. I'd remove it completely, but seems like it was decided to keep it in case someone would like to support it one day...
> > Reviewed-by: Eric Dumazet <edumazet@google.com>
Thanks, Olek
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