4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Omar Sandoval <osandov@xxxxxx>
[ Upstream commit 6bf6b0aa3da84a3d9126919a94c49c0fb7ee2fb3 ]
If blk_mq_init_queue() returns an error, it gets assigned to
vblk->disk->queue. Then, when we call put_disk(), we end up calling
blk_put_queue() with the ERR_PTR, causing a bad dereference. Fix it by
only assigning to vblk->disk->queue on success.
Signed-off-by: Omar Sandoval <osandov@xxxxxx>
Reviewed-by: Jeff Moyer <jmoyer@xxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/block/virtio_blk.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -641,11 +641,12 @@ static int virtblk_probe(struct virtio_d
if (err)
goto out_put_disk;
- q = vblk->disk->queue = blk_mq_init_queue(&vblk->tag_set);
+ q = blk_mq_init_queue(&vblk->tag_set);
if (IS_ERR(q)) {
err = -ENOMEM;
goto out_free_tags;
}
+ vblk->disk->queue = q;
q->queuedata = vblk;