6.1-stable review patch. If anyone has any objections, please let me know.
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From: Will Deacon will@kernel.org
commit 0dab92484474587b82e8e0455839eaf5ac7bf894 upstream.
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 Message-Id: 20250717090116.11987-3-will@kernel.org Signed-off-by: Michael S. Tsirkin mst@redhat.com Reviewed-by: Stefano Garzarella sgarzare@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/vmw_vsock/virtio_transport.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
--- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c @@ -494,8 +494,9 @@ static void virtio_transport_rx_work(str 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 @@ -512,11 +513,18 @@ static void virtio_transport_rx_work(str 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);