paride/pcd: need to set queue to NULL before put_disk

In pcd_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: f0d176255401 ("paride/pcd: Fix potential NULL pointer dereference and mem leak")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/block/paride/pcd.c b/drivers/block/paride/pcd.c
index 001dbdc..bfca80d 100644 (file)
--- a/drivers/block/paride/pcd.c
+++ b/drivers/block/paride/pcd.c
@@ -314,8 +314,8 @@ static void pcd_init_units(void)
                disk->queue = blk_mq_init_sq_queue(&cd->tag_set, &pcd_mq_ops,
                                                   1, BLK_MQ_F_SHOULD_MERGE);
                if (IS_ERR(disk->queue)) {
-                       put_disk(disk);
                        disk->queue = NULL;
+                       put_disk(disk);
                        continue;
                }