This is a note to let you know that I've just added the patch titled
vsock/virtio: fix potential unbounded skb queue
to the 6.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
vsock-virtio-fix-potential-unbounded-skb-queue.patch
and it can be found in the queue-6.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 059b7dbd20a6f0c539a45ddff1573cb8946685b5 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <[email protected]>
Date: Thu, 30 Apr 2026 12:26:52 +0000
Subject: vsock/virtio: fix potential unbounded skb queue
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From: Eric Dumazet <[email protected]>
commit 059b7dbd20a6f0c539a45ddff1573cb8946685b5 upstream.
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]>
Cc: Luigi Leonardi <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
net/vmw_vsock/virtio_transport_common.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -429,7 +429,9 @@ static int virtio_transport_send_pkt_inf
static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
u32 len)
{
- if (vvs->buf_used + len > vvs->buf_alloc)
+ u64 skb_overhead = (skb_queue_len(&vvs->rx_queue) + 1) *
SKB_TRUESIZE(0);
+
+ if (skb_overhead + vvs->buf_used + len > vvs->buf_alloc)
return false;
vvs->rx_bytes += len;
Patches currently in stable-queue which might be from [email protected] are
queue-6.18/vsock-virtio-fix-potential-unbounded-skb-queue.patch
