[PATCH] paride/pf: need to set queue to NULL before put_disk

[zhengbin <zhengbin13@xxxxxxxxxx>]

In pf_init_units, if blk_mq_init_sq_queue fails, need to set queue to
NULL before put_disk, otherwise null-ptr-deref Read will occur.

put_disk
  kobject_put
    disk_release
      blk_put_queue(disk->queue)

Fixes: 77218ddf46d8 ("paride: convert pf to blk-mq")
Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
Signed-off-by: zhengbin <zhengbin13@xxxxxxxxxx>
---
 drivers/block/paride/pf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/block/paride/pf.c b/drivers/block/paride/pf.c
index 1e9c50a..6b7d4ca 100644
--- a/drivers/block/paride/pf.c
+++ b/drivers/block/paride/pf.c
@@ -300,8 +300,8 @@ static void __init pf_init_units(void)
 		disk->queue = blk_mq_init_sq_queue(&pf->tag_set, &pf_mq_ops,
 							1, BLK_MQ_F_SHOULD_MERGE);
 		if (IS_ERR(disk->queue)) {
-			put_disk(disk);
 			disk->queue = NULL;
+			put_disk(disk);
 			continue;
 		}

--
2.7.4