From: John Garry <john.garry@huawei.com> mainline inclusion from mainline-v5.16-rc1 commit 65de57bb2e66f1fbede166c1307570ebd09eae83 category: performance 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/?i... -------------------------------- The original code in commit 24d2f90309b23 ("blk-mq: split out tag initialization, support shared tags") would check tags->rqs is non-NULL and then dereference tags->rqs[]. Then in commit 2af8cbe30531 ("blk-mq: split tag ->rqs[] into two"), we started to dereference tags->static_rqs[], but continued to check non-NULL tags->rqs. Check tags->static_rqs as non-NULL instead, which is more logical. Signed-off-by: John Garry <john.garry@huawei.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/1633429419-228500-2-git-send-email-john.garry@huaw... Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Jason Yan <yanaijie@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- block/blk-mq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 61477c824823..2c2e82163d3b 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2470,7 +2470,7 @@ void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, { struct page *page; - if (tags->rqs && set->ops->exit_request) { + if (tags->static_rqs && set->ops->exit_request) { int i; for (i = 0; i < tags->nr_tags; i++) { -- 2.20.1