disk_release() undoes blk_mq_init_allocated_queue() for a disk whose probe failed before add_disk(), but it only calls blk_mq_exit_queue(). Nothing there stops q->timeout, and that timer rolls forward: it stays pending until it next expires, not until the last request completes. So if the driver issued any I/O before adding the disk, the request_queue is freed while still linked into a timer wheel bucket. Commit 6f8191fdf41d ("block: simplify disk shutdown") dropped the blk_cleanup_queue() call that used to stop it. __del_gendisk() and blk_mq_destroy_queue() still do; only the probe failure path lost it. nvme gets there because nvme_update_ns_info() submits Report Zones or FDP io-mgmt-recv on ns->queue before the disk is added, so a later failure - a concurrent reset setting NVME_CTRL_FROZEN, or device_add_disk() failing - lands in put_disk() with the timer armed: BUG: KASAN: slab-use-after-free in detach_if_pending+0x30c/0x340 Write of size 8 at addr ffff888004d71310 by task kworker/u8:2/37 __timer_delete_sync+0x156/0x240 kernel/time/timer.c:1621 blk_sync_queue+0x22/0x40 block/blk-core.c:222 nvme_sync_queues+0x100/0x150 drivers/nvme/host/core.c:5362 nvme_reset_work+0x138/0x930 drivers/nvme/host/pci.c:3264 Allocated by task 34: __blk_mq_alloc_disk+0x33/0x100 block/blk-mq.c:4462 nvme_alloc_ns+0x290/0x3870 drivers/nvme/host/core.c:4146 Freed by task 0: blk_free_queue_rcu+0x3a/0x50 block/blk-core.c:254 rcu_core+0xc10/0x1730 kernel/rcu/tree.c:2857 The queue being synced there is ctrl->admin_q, only a victim sharing a timer wheel bucket with the freed queue's dangling entry; other runs tripped in enqueue_timer(), __run_timers() or blk_mq_timeout_work(). Failing nvme_alloc_ns() with a debug patch makes it deterministic: one leaked timer trips KASAN within seconds, while 1987 patched releases produced no splat. Stop the timer and the queue work items before blk_mq_exit_queue(), like blk_mq_destroy_queue() does. Found by FuzzNvme. Fixes: 6f8191fdf41d ("block: simplify disk shutdown") Acked-by: Weidong Zhu Signed-off-by: Chao Shi --- block/genhd.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index df2c3c69b467..e8ce0cabf392 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1281,14 +1281,18 @@ static void disk_release(struct device *dev) /* * To undo the all initialization from blk_mq_init_allocated_queue in * case of a probe failure where add_disk is never called we have to - * call blk_mq_exit_queue here. We can't do this for the more common - * teardown case (yet) as the tagset can be gone by the time the disk - * is released once it was added. + * call blk_mq_exit_queue here, after stopping the timer and work items + * that I/O issued before add_disk may have left pending. We can't do + * this for the more common teardown case (yet) as the tagset can be + * gone by the time the disk is released once it was added. */ if (queue_is_mq(disk->queue) && test_bit(GD_OWNS_QUEUE, &disk->state) && - !test_bit(GD_ADDED, &disk->state)) + !test_bit(GD_ADDED, &disk->state)) { + blk_sync_queue(disk->queue); + blk_mq_cancel_work_sync(disk->queue); blk_mq_exit_queue(disk->queue); + } blkcg_exit_disk(disk); -- 2.43.0