From: zhengbin <zhengbin13@huawei.com>
Date: Tue, 13 Aug 2019 11:27:40 +0000 (+0800)
Subject: paride/pcd: need to set queue to NULL before put_disk
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=d821cce8ac4625ceecabb9c9e2420daaf41d41d8;p=linux.git

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 001dbdcbf3557..bfca80dde7db2 100644
--- 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;
 		}