[PATCH 4.9 43/63] vhost/vsock: fix uninitialized vhost_vsock->guest_cid

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stefan Hajnoczi <stefanha@xxxxxxxxxx>

commit a72b69dc083a931422cc8a5e33841aff7d5312f2 upstream.

The vhost_vsock->guest_cid field is uninitialized when /dev/vhost-vsock
is opened until the VHOST_VSOCK_SET_GUEST_CID ioctl is called.

kvmalloc(..., GFP_KERNEL | __GFP_RETRY_MAYFAIL) does not zero memory.
All other vhost_vsock fields are initialized explicitly so just
initialize this field too.

Signed-off-by: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Cc: Daniel Verkamp <dverkamp@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/vhost/vsock.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -520,6 +520,8 @@ static int vhost_vsock_dev_open(struct i
 		goto out;
 	}
 
+	vsock->guest_cid = 0; /* no CID assigned yet */
+
 	atomic_set(&vsock->queued_replies, 0);
 
 	vqs[VSOCK_VQ_TX] = &vsock->vqs[VSOCK_VQ_TX];