vhost: validate vhost_get_vq_desc return value
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>
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 026be58..e1e22e0 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -505,9 +505,13 @@
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;