On Fri, May 15, 2026 at 05:10:39PM +0200, Greg KH wrote:
> 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 :(

Ah, is this due to your other email?  that makes more sense, sorry for
the noise.

greg "drowning in email" k-h

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