blk-mq-sched: Don't reference queue tagset in blk_mq_sched_tags_teardown()

mainline inclusion
from mainline-v5.16-rc1
commit 8bdf7b3f
category: bugfix
bugzilla: 186917, https://gitee.com/openeuler/kernel/issues/I5N1S5
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8bdf7b3fe1f48a2c1c212d4685903bba01409c0e

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

We should not reference the queue tagset in blk_mq_sched_tags_teardown()
(see function comment) for the blk-mq flags, so use the passed flags
instead.

This solves a use-after-free, similarly fixed earlier (and since broken
again) in commit f0c1c4d2 ("blk-mq: fix use-after-free in
blk_mq_exit_sched").
Reported-by: NLinux Kernel Functional Testing <lkft@linaro.org>
Reported-by: NNaresh Kamboju <naresh.kamboju@linaro.org>
Tested-by: NAnders Roxell <anders.roxell@linaro.org>
Fixes: e155b0c2 ("blk-mq: Use shared tags for shared sbitmap support")
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/1634890340-15432-1-git-send-email-john.garry@huawei.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Conflict:
	block/blk-mq-sched.c
Signed-off-by: NZhang Wensheng <zhangwensheng5@huawei.com>
Reviewed-by: NYu Kuai <yukuai3@huawei.com>
Reviewed-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

block/blk-mq-sched.c

@@ -545,7 +545,7 @@ static void blk_mq_sched_tags_teardown(struct request_queue *q, unsigned int fla
 
 	queue_for_each_hw_ctx(q, hctx, i) {
 		if (hctx->sched_tags) {
-			if (!blk_mq_is_sbitmap_shared(q->tag_set->flags))
+			if (!blk_mq_is_sbitmap_shared(flags))
 				blk_mq_free_rq_map(hctx->sched_tags);
 			hctx->sched_tags = NULL;
 		}