From: Li Nan <linan122@huawei.com> hulk inclusion category: bugfix bugzilla: 188174, https://gitee.com/openeuler/kernel/issues/I677QO CVE: NA -------------------------------- bfqg->bfqd is assigned in bfq_pd_init(). bfqg may be allocted but not initialized when bfq_pd_alloc() return NULL in blkcg_activate_policy(). queue_lock is unlock now and delete cgroup at this time will cause error. T1 T2 bfq_init_queue bfq_create_group_hierarchy blkcg_activate_policy traverse q->blkg_list 1)pd_alloc_fn success blkg->pd[pol->plid] = pd 2)pd_alloc_fn fail spin_unlock_irq(&q->queue_lock) -> 1)is alloced but not init blkcg_destroy_blkgs blkg_destroy if blkg->pd[i] bfq_pd_offline use bfqg->bfqd -> error Signed-off-by: Li Nan <linan122@huawei.com> Reviewed-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- block/bfq-cgroup.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c index 36ba7324f685..a285711f1b48 100644 --- a/block/bfq-cgroup.c +++ b/block/bfq-cgroup.c @@ -911,6 +911,9 @@ static void bfq_pd_offline(struct blkg_policy_data *pd) unsigned long flags; int i; + if (!bfqg->online) + return; + spin_lock_irqsave(&bfqd->lock, flags); if (!entity) /* root group */ -- 2.20.1