diff mbox

[CVE-2014-0055,Quantal] vhost: validate vhost_get_vq_desc return value

Message ID 1396874258-1846-1-git-send-email-luis.henriques@canonical.com
State New
Headers show

Commit Message

Luis Henriques April 7, 2014, 12:37 p.m. UTC 
From: "Michael S. Tsirkin" <mst@redhat.com>

vhost fails to validate negative error code
from vhost_get_vq_desc causing
a crash: we are using -EFAULT which is 0xfffffff2
as vector size, which exceeds the allocated size.

The code in question was introduced in commit
8dd014adfea6f173c1ef6378f7e5e7924866c923
    vhost-net: mergeable buffers support

CVE-2014-0055

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit a39ee449f96a2cd44ce056d8a0a112211a9b1a1f)
BugLink: http://bugs.launchpad.net/bugs/1298117
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 drivers/vhost/net.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

Comments

Tim Gardner April 7, 2014, 4:59 p.m. UTC | #1
diff mbox

Patch

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index f2e8236..b810359 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -327,9 +327,13 @@  static int get_rx_bufs(struct vhost_virtqueue *vq,
 			r = -ENOBUFS;
 			goto err;
 		}
-		d = vhost_get_vq_desc(vq->dev, vq, vq->iov + seg,
+		r = vhost_get_vq_desc(vq->dev, vq, vq->iov + seg,
 				      ARRAY_SIZE(vq->iov) - seg, &out,
 				      &in, log, log_num);
+		if (unlikely(r < 0))
+			goto err;
+
+		d = r;
 		if (d == vq->num) {
 			r = 0;
 			goto err;