From: "Michael S. Tsirkin" mst@redhat.com
stable inclusion from stable-v5.10.94 commit 56daa21414e9cf66131de3458ba389a1f3a9c690 bugzilla: https://gitee.com/openeuler/kernel/issues/I531X9
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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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@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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com --- drivers/virtio/virtio_ring.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index cce75d3b3ba0..3cc2a4ee7152 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -1124,8 +1124,10 @@ 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 */ }