From: Michael S. Tsirkin <mst@redhat.com>
Date: Thu, 6 Jan 2022 12:57:46 +0000 (-0500)
Subject: virtio_ring: mark ring unused on error
X-Git-Tag: v6.6.17~8368^2~19
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=1861ba626ae9b98136f3e504208cdef6b29cd3ec;p=platform%2Fkernel%2Flinux-rpi.git

virtio_ring: mark ring unused on error

A recently added error path does not mark ring unused when exiting on
OOM, which will lead to BUG on the next entry in debug builds.

TODO: refactor code so we have START_USE and END_USE in the same function.

Fixes: fc6d70f40b3d ("virtio_ring: check desc == NULL when using indirect with packed")
Cc: "Xuan Zhuo" <xuanzhuo@linux.alibaba.com>
Cc: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 028b05d44546..962f1477b1fa 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1197,8 +1197,10 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
 	if (virtqueue_use_indirect(_vq, total_sg)) {
 		err = virtqueue_add_indirect_packed(vq, sgs, total_sg, out_sgs,
 						    in_sgs, data, gfp);
-		if (err != -ENOMEM)
+		if (err != -ENOMEM) {
+			END_USE(vq);
 			return err;
+		}
 
 		/* fall back on direct */
 	}