Commit 0dab9248 authored by Will Deacon's avatar Will Deacon Committed by Michael S. Tsirkin
Browse files

vsock/virtio: Validate length in packet header before skb_put() 



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: 71dc9ec9 ("virtio/vsock: replace virtio_vsock_pkt with sk_buff")
Signed-off-by: default avatarWill Deacon <will@kernel.org>
Message-Id: <20250717090116.11987-3-will@kernel.org>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: default avatarStefano Garzarella <sgarzare@redhat.com>
parent 10a886aa

net/vmw_vsock/virtio_transport.c

+10 −2
Original line number Diff line number Diff line
@@ -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);