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 Pérez <[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. Luigi
