On Thu, Jul 17, 2025 at 10:01:09AM +0100, Will Deacon wrote:
When receiving a vsock packet in the guest, only the virtqueue buffer size is validated prior to virtio_vsock_skb_rx_put(). Unfortunately, virtio_vsock_skb_rx_put() uses the length from the packet header as the length argument to skb_put(), potentially resulting in SKB overflow if the host has gone wonky.
Validate the length as advertised by the packet header before calling virtio_vsock_skb_rx_put().
Cc: stable@vger.kernel.org Fixes: 71dc9ec9ac7d ("virtio/vsock: replace virtio_vsock_pkt with sk_buff") Signed-off-by: Will Deacon will@kernel.org
net/vmw_vsock/virtio_transport.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
Reviewed-by: Stefano Garzarella sgarzare@redhat.com
diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c index f0e48e6911fc..eb08a393413d 100644 --- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c @@ -624,8 +624,9 @@ static void virtio_transport_rx_work(struct work_struct *work) do { virtqueue_disable_cb(vq); for (;;) {
unsigned int len, payload_len;struct virtio_vsock_hdr *hdr; struct sk_buff *skb;
unsigned int len; if (!virtio_transport_more_replies(vsock)) { /* Stop rx until the device processes already@@ -642,12 +643,19 @@ static void virtio_transport_rx_work(struct work_struct *work) vsock->rx_buf_nr--;
/* Drop short/long packets */
if (unlikely(len < sizeof(struct virtio_vsock_hdr) ||
if (unlikely(len < sizeof(*hdr) || len > virtio_vsock_skb_len(skb))) { kfree_skb(skb); continue; }hdr = virtio_vsock_hdr(skb);payload_len = le32_to_cpu(hdr->len);if (unlikely(payload_len > len - sizeof(*hdr))) {kfree_skb(skb);continue;}virtio_vsock_skb_rx_put(skb); virtio_transport_deliver_tap_pkt(skb); virtio_transport_recv_pkt(&virtio_transport, skb);-- 2.50.0.727.gbf7dc18ff4-goog