From: Lihong Kou <koulihong@huawei.com> mainline inclusion from mainline-v5.15 commit 3df49967f6f1d2121b0c27c381ca1c8386b1dab9 category: bugfix bugzilla: 181328 CVE: NA ----------------------------------------------- When the integrity profile is unregistered there can still be integrity reads queued up which could see a NULL verify_fn as shown by the race window below: CPU0 CPU1 process_one_work nvme_validate_ns bio_integrity_verify_fn nvme_update_ns_info nvme_update_disk_info blk_integrity_unregister ---set queue->integrity as 0 bio_integrity_process --access bi->profile->verify_fn(bi is a pointer of queue->integity) Before calling blk_integrity_unregister in nvme_update_disk_info, we must make sure that there is no work item in the kintegrityd_wq. Just call blk_flush_integrity to flush the work queue so the bug can be resolved. Signed-off-by: Lihong Kou <koulihong@huawei.com> [hch: split up and shortened the changelog] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Link: https://lore.kernel.org/r/20210914070657.87677-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- block/blk-integrity.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/block/blk-integrity.c b/block/blk-integrity.c index 0638f4868f705..0b01fa972f1fc 100644 --- a/block/blk-integrity.c +++ b/block/blk-integrity.c @@ -436,6 +436,8 @@ void blk_integrity_unregister(struct gendisk *disk) if (!bi->profile) return; + /* ensure all bios are off the integrity workqueue */ + blk_flush_integrity(); disk->queue->backing_dev_info->capabilities &= ~BDI_CAP_STABLE_WRITES; memset(bi, 0, sizeof(*bi)); } -- 2.25.1