block: fix use-after-free of q->q_usage_counter

mainline inclusion
from mainline-v6.2-rc1
commit d36a9ea5
category: bugfix
bugzilla: 187268, https://gitee.com/openeuler/kernel/issues/I5N162

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d36a9ea5e7766961e753ee38d4c331bbe6ef659b

----------------------------------------

For blk-mq, queue release handler is usually called after
blk_mq_freeze_queue_wait() returns. However, the
q_usage_counter->release() handler may not be run yet at that time, so
this can cause a use-after-free.

Fix the issue by moving percpu_ref_exit() into blk_free_queue_rcu().
Since ->release() is called with rcu read lock held, it is agreed that
the race should be covered in caller per discussion from the two links.
Reported-by: NZhang Wensheng <zhangwensheng@huaweicloud.com>
Reported-by: NZhong Jinghua <zhongjinghua@huawei.com>
Link: https://lore.kernel.org/linux-block/Y5prfOjyyjQKUrtH@T590/T/#u
Link: https://lore.kernel.org/lkml/Y4%2FmzMd4evRg9yDi@fedora/
Cc: Hillf Danton <hdanton@sina.com>
Cc: Yu Kuai <yukuai3@huawei.com>
Cc: Dennis Zhou <dennis@kernel.org>
Fixes: 2b0d3d3e ("percpu_ref: reduce memory footprint of percpu_ref in fast path")
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20221215021629.74870-1-ming.lei@redhat.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

conflicts:
 block/blk-sysfs.c
 block/blk-core.c
Signed-off-by: NZhong Jinghua <zhongjinghua@huawei.com>
Reviewed-by: NHou Tao <houtao1@huawei.com>
Signed-off-by: NJialin Zhang <zhangjialin11@huawei.com>

block/blk-sysfs.c

@@ -726,6 +726,8 @@ static void blk_free_queue_rcu(struct rcu_head *rcu_head)
 {
 	struct request_queue *q = container_of(rcu_head, struct request_queue,
 					       rcu_head);
+
+	percpu_ref_exit(&q->q_usage_counter);
 	kmem_cache_free(blk_requestq_cachep, q);
 }
 
@@ -784,8 +786,6 @@ static void blk_release_queue(struct kobject *kobj)
 
 	might_sleep();
 
-	percpu_ref_exit(&q->q_usage_counter);
-
 	if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags))
 		blk_stat_remove_callback(q, q->poll_cb);
 	blk_stat_free_callback(q->poll_cb);