[PATCH -next] virtio: fix possible memory leak in virtqueue_add()

desc may malloced in virtqueue_add() and should be freed before
leaving from the error handling cases, otherwise it will cause
memory leak.

Signed-off-by: Wei Yongjun <redacted>
---
 drivers/virtio/virtio_ring.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 114a0c8..bda71ef 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c

@@ -328,6 +328,7 @@ static inline int virtqueue_add(struct virtqueue *_vq,
 		if (out_sgs)
 			vq->notify(&vq->vq);
 		END_USE(vq);
+		kfree(desc);
 		return -ENOSPC;
 	}