From: Wei Yongjun <weiyj.lk@gmail.com>
Date: Tue, 2 Aug 2016 14:16:31 +0000 (+0000)
Subject: virtio: fix memory leak in virtqueue_add()
X-Git-Tag: firefly_0821_release~176^2~4^2~31^2~295
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=fa54eea35b3882b18da94d932b78c519c3972bd8;p=firefly-linux-kernel-4.4.55.git

virtio: fix memory leak in virtqueue_add()

commit 58625edf9e2515ed41dac2a24fa8004030a87b87 upstream.

When using the indirect buffers feature, 'desc' is allocated in
virtqueue_add() but isn't freed before leaving on a ring full error,
causing a memory leak.

For example, it seems rather clear that this can trigger
with virtio net if mergeable buffers are not used.

Signed-off-by: Wei Yongjun <weiyj.lk@gmail.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index ee663c458b20..dc2b94142f53 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -202,6 +202,8 @@ static inline int virtqueue_add(struct virtqueue *_vq,
 		 * host should service the ring ASAP. */
 		if (out_sgs)
 			vq->notify(&vq->vq);
+		if (indirect)
+			kfree(desc);
 		END_USE(vq);
 		return -ENOSPC;
 	}