From: Michael S. Tsirkin <mst@xxxxxxxxxx> commit 1861ba626ae9b98136f3e504208cdef6b29cd3ec upstream. 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@xxxxxxxxxxxxxxxxx> Cc: Jiasheng Jiang <jiasheng@xxxxxxxxxxx> Reviewed-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/virtio/virtio_ring.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -1197,8 +1197,10 @@ static inline int virtqueue_add_packed(s 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 */ }