On Fri, May 15, 2026 at 04:23:53PM +0200, Luigi Leonardi wrote:
> On Fri, May 15, 2026 at 04:22:12PM +0200, Luigi Leonardi wrote:
> > From: Eric Dumazet <[email protected]>
> > 
> > Upstream commit 059b7dbd20a6f0c539a45ddff1573cb8946685b5
> > 
> > virtio_transport_inc_rx_pkt() checks vvs->rx_bytes + len > vvs->buf_alloc.
> > 
> > virtio_transport_recv_enqueue() skips coalescing for packets
> > with VIRTIO_VSOCK_SEQ_EOM.
> > 
> > If fed with packets with len == 0 and VIRTIO_VSOCK_SEQ_EOM,
> > a very large number of packets can be queued
> > because vvs->rx_bytes stays at 0.
> > 
> > Fix this by estimating the skb metadata size:
> > 
> >     (Number of skbs in the queue) * SKB_TRUESIZE(0)
> > 
> > Fixes: 077706165717 ("virtio/vsock: don't use skbuff state to account 
> > credit")
> > Signed-off-by: Eric Dumazet <[email protected]>
> > Cc: Arseniy Krasnov <[email protected]>
> > Cc: Stefan Hajnoczi <[email protected]>
> > Cc: Stefano Garzarella <[email protected]>
> > Cc: Michael S. Tsirkin <[email protected]>
> > Cc: Jason Wang <[email protected]>
> > Cc: Xuan Zhuo <[email protected]>
> > Cc: Eugenio PĂ©rez <[email protected]>
> > Cc: [email protected]
> > Link: https://patch.msgid.link/[email protected]
> > Signed-off-by: Jakub Kicinski <[email protected]>
> > [LL: Fixed conflict since this tree does not use buf_used added by commit
> > 45ca7e9f0730 ("vsock/virtio: fix `rx_bytes` accounting for stream sockets")]
> > Signed-off-by: Luigi Leonardi <[email protected]>
> > ---
> > net/vmw_vsock/virtio_transport_common.c | 4 +++-
> > 1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/net/vmw_vsock/virtio_transport_common.c 
> > b/net/vmw_vsock/virtio_transport_common.c
> > index 4c374c36c29d..86e3051d000e 100644
> > --- a/net/vmw_vsock/virtio_transport_common.c
> > +++ b/net/vmw_vsock/virtio_transport_common.c
> > @@ -283,7 +283,9 @@ static int virtio_transport_send_pkt_info(struct 
> > vsock_sock *vsk,
> > static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
> >                                     u32 len)
> > {
> > -   if (vvs->rx_bytes + len > vvs->buf_alloc)
> > +   u64 skb_overhead = (skb_queue_len(&vvs->rx_queue) + 1) * 
> > SKB_TRUESIZE(0);
> > +
> > +   if (skb_overhead + vvs->rx_bytes + len > vvs->buf_alloc)
> >             return false;
> > 
> >     vvs->rx_bytes += len;
> > 
> > ---
> > base-commit: 3b9f64db049687c0d38b4b3ef2f297f0642179af
> > change-id: 20260515-dumazet-07c0c855a9e2
> > 
> > Best regards,
> > --
> > Luigi Leonardi <[email protected]>
> > 
> 
> Forgot to add this is material for 6.6.y stable tree.

What about all of the newer stable trees?  You can't just apply a patch
to an old branch :(

thanks,

greg k-h

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