From: Stefano Garzarella <sgarzare@redhat.com>
Date: Fri, 6 Dec 2019 14:39:12 +0000 (+0100)
Subject: vhost/vsock: accept only packets with the right dst_cid
X-Git-Tag: v4.9.208~5
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0a8f421b7a224447ac4ebdef466ad6151023b33d;p=thirdparty%2Fkernel%2Fstable.git

vhost/vsock: accept only packets with the right dst_cid

[ Upstream commit 8a3cc29c316c17de590e3ff8b59f3d6cbfd37b0a ]

When we receive a new packet from the guest, we check if the
src_cid is correct, but we forgot to check the dst_cid.

The host should accept only packets where dst_cid is
equal to the host CID.

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index a775493b7b67d..2e37097916b5b 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -399,7 +399,9 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work *work)
 		len = pkt->len;
 
 		/* Only accept correctly addressed packets */
-		if (le64_to_cpu(pkt->hdr.src_cid) == vsock->guest_cid)
+		if (le64_to_cpu(pkt->hdr.src_cid) == vsock->guest_cid &&
+		    le64_to_cpu(pkt->hdr.dst_cid) ==
+		    vhost_transport_get_local_cid())
 			virtio_transport_recv_pkt(pkt);
 		else
 			virtio_transport_free_pkt(pkt);