4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Halil Pasic <pasic@xxxxxxxxxxxxx>
commit 3438b2c039b4bf26881786a1f3450f016d66ad11 upstream.
A queue with a capacity of zero is clearly not a valid virtio queue.
Some emulators report zero queue size if queried with an invalid queue
index. Instead of crashing in this case let us just return -ENOENT. To
make that work properly, let us fix the notifier cleanup logic as well.
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Halil Pasic <pasic@xxxxxxxxxxxxx>
Signed-off-by: Cornelia Huck <cohuck@xxxxxxxxxx>
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/s390/virtio/virtio_ccw.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/s390/virtio/virtio_ccw.c
+++ b/drivers/s390/virtio/virtio_ccw.c
@@ -272,6 +272,8 @@ static void virtio_ccw_drop_indicators(s
{
struct virtio_ccw_vq_info *info;
+ if (!vcdev->airq_info)
+ return;
list_for_each_entry(info, &vcdev->virtqueues, node)
drop_airq_indicator(info->vq, vcdev->airq_info);
}
@@ -413,7 +415,7 @@ static int virtio_ccw_read_vq_conf(struc
ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
if (ret)
return ret;
- return vcdev->config_block->num;
+ return vcdev->config_block->num ?: -ENOENT;
}
static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
