Messages in this thread Patch in this message | | | From | Li Nan <> | Subject | [PATCH -next v2 8/9] block: fix null-pointer dereference in ioc_pd_init | Date | Wed, 30 Nov 2022 21:21:55 +0800 |
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Remove block device when iocost is initializing may cause null-pointer dereference:
CPU1 CPU2 ioc_qos_write blkcg_conf_open_bdev blkdev_get_no_open kobject_get_unless_zero blk_iocost_init rq_qos_add del_gendisk rq_qos_exit q->rq_qos = rqos->next //iocost is removed from q->roqs blkcg_activate_policy pd_init_fn ioc_pd_init ioc = q_to_ioc(blkg->q) //cant find iocost and return null
Fix problem by moving rq_qos_exit() to disk_release(). ioc_qos_write() get bd_device.kobj in blkcg_conf_open_bdev(), so disk_release will not be actived until iocost initialization is complited.
Signed-off-by: Li Nan <linan122@huawei.com> --- block/genhd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/genhd.c b/block/genhd.c index dcf200bcbd3e..0db440bbfefb 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -656,7 +656,6 @@ void del_gendisk(struct gendisk *disk) elevator_exit(q); mutex_unlock(&q->sysfs_lock); } - rq_qos_exit(q); blk_mq_unquiesce_queue(q); /* @@ -1168,6 +1167,7 @@ static void disk_release(struct device *dev) !test_bit(GD_ADDED, &disk->state)) blk_mq_exit_queue(disk->queue); + rq_qos_exit(disk->queue); blkcg_exit_disk(disk); bioset_exit(&disk->bio_split); -- 2.31.1
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