====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kworker/u4:0/9 is trying to acquire lock: ffff0000ce8a3818 ((work_completion)(&q->timeout_work)){+.+.}-{0:0}, at: __flush_work+0xe4/0x1ec kernel/workqueue.c:3069 but task is already holding lock: ffff0000cfb48528 (&ctrl->namespaces_rwsem){++++}-{3:3}, at: nvme_sync_io_queues drivers/nvme/host/core.c:5465 [inline] ffff0000cfb48528 (&ctrl->namespaces_rwsem){++++}-{3:3}, at: nvme_sync_queues+0x2c/0xf4 drivers/nvme/host/core.c:5474 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&ctrl->namespaces_rwsem){++++}-{3:3}: down_read+0x64/0x300 kernel/locking/rwsem.c:1520 nvme_start_freeze+0x2c/0xc0 drivers/nvme/host/core.c:5416 nvme_dev_disable+0x1b8/0x5ec drivers/nvme/host/pci.c:2747 nvme_timeout+0x628/0xa88 drivers/nvme/host/pci.c:-1 blk_mq_rq_timed_out block/blk-mq.c:1566 [inline] blk_mq_handle_expired+0x148/0x270 block/blk-mq.c:1634 bt_iter+0x2e4/0x3bc block/blk-mq-tag.c:295 __sbitmap_for_each_set include/linux/sbitmap.h:286 [inline] sbitmap_for_each_set+0x2b8/0x558 include/linux/sbitmap.h:307 bt_for_each block/blk-mq-tag.c:327 [inline] blk_mq_queue_tag_busy_iter+0x440/0x730 block/blk-mq-tag.c:536 blk_mq_timeout_work+0x16c/0x300 block/blk-mq.c:1676 process_one_work+0x7e4/0x13bc kernel/workqueue.c:2292 worker_thread+0x8cc/0xfe8 kernel/workqueue.c:2439 kthread+0x254/0x2e0 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850 -> #1 (&dev->shutdown_lock){+.+.}-{3:3}: __mutex_lock_common+0x1a0/0x1f3c kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 nvme_dev_disable+0x5c/0x5ec drivers/nvme/host/pci.c:2735 nvme_timeout+0x628/0xa88 drivers/nvme/host/pci.c:-1 blk_mq_rq_timed_out block/blk-mq.c:1566 [inline] blk_mq_handle_expired+0x148/0x270 block/blk-mq.c:1634 bt_iter+0x2e4/0x3bc block/blk-mq-tag.c:295 __sbitmap_for_each_set include/linux/sbitmap.h:286 [inline] sbitmap_for_each_set+0x2b8/0x558 include/linux/sbitmap.h:307 bt_for_each block/blk-mq-tag.c:327 [inline] blk_mq_queue_tag_busy_iter+0x440/0x730 block/blk-mq-tag.c:536 blk_mq_timeout_work+0x16c/0x300 block/blk-mq.c:1676 process_one_work+0x7e4/0x13bc kernel/workqueue.c:2292 worker_thread+0x8cc/0xfe8 kernel/workqueue.c:2439 kthread+0x254/0x2e0 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850 -> #0 ((work_completion)(&q->timeout_work)){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3830 [inline] __lock_acquire+0x2808/0x6634 kernel/locking/lockdep.c:5063 lock_acquire+0x20c/0x638 kernel/locking/lockdep.c:5676 __flush_work+0x10c/0x1ec kernel/workqueue.c:3072 __cancel_work_timer+0x2f8/0x450 kernel/workqueue.c:3163 cancel_work_sync+0x24/0x38 kernel/workqueue.c:3199 blk_sync_queue+0x28/0x38 block/blk-core.c:232 nvme_sync_io_queues drivers/nvme/host/core.c:5467 [inline] nvme_sync_queues+0x70/0xf4 drivers/nvme/host/core.c:5474 nvme_reset_work+0x13c/0x477c drivers/nvme/host/pci.c:2890 process_one_work+0x7e4/0x13bc kernel/workqueue.c:2292 worker_thread+0x8cc/0xfe8 kernel/workqueue.c:2439 kthread+0x254/0x2e0 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850 other info that might help us debug this: Chain exists of: (work_completion)(&q->timeout_work) --> &dev->shutdown_lock --> &ctrl->namespaces_rwsem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ctrl->namespaces_rwsem); lock(&dev->shutdown_lock); lock(&ctrl->namespaces_rwsem); lock((work_completion)(&q->timeout_work)); *** DEADLOCK *** 3 locks held by kworker/u4:0/9: #0: ffff0000cfaf1938 ((wq_completion)nvme-reset-wq){+.+.}-{0:0}, at: process_one_work+0x69c/0x13bc kernel/workqueue.c:-1 #1: ffff80001cb37c40 ((work_completion)(&dev->ctrl.reset_work)){+.+.}-{0:0}, at: process_one_work+0x6e8/0x13bc kernel/workqueue.c:2267 #2: ffff0000cfb48528 (&ctrl->namespaces_rwsem){++++}-{3:3}, at: nvme_sync_io_queues drivers/nvme/host/core.c:5465 [inline] #2: ffff0000cfb48528 (&ctrl->namespaces_rwsem){++++}-{3:3}, at: nvme_sync_queues+0x2c/0xf4 drivers/nvme/host/core.c:5474 stack backtrace: CPU: 0 PID: 9 Comm: kworker/u4:0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/07/2026 Workqueue: nvme-reset-wq nvme_reset_work Call trace: dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106 dump_stack+0x1c/0x5c lib/dump_stack.c:113 print_circular_bug+0x148/0x1b0 kernel/locking/lockdep.c:2048 check_noncircular+0x264/0x2f8 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3830 [inline] __lock_acquire+0x2808/0x6634 kernel/locking/lockdep.c:5063 lock_acquire+0x20c/0x638 kernel/locking/lockdep.c:5676 __flush_work+0x10c/0x1ec kernel/workqueue.c:3072 __cancel_work_timer+0x2f8/0x450 kernel/workqueue.c:3163 cancel_work_sync+0x24/0x38 kernel/workqueue.c:3199 blk_sync_queue+0x28/0x38 block/blk-core.c:232 nvme_sync_io_queues drivers/nvme/host/core.c:5467 [inline] nvme_sync_queues+0x70/0xf4 drivers/nvme/host/core.c:5474 nvme_reset_work+0x13c/0x477c drivers/nvme/host/pci.c:2890 process_one_work+0x7e4/0x13bc kernel/workqueue.c:2292 worker_thread+0x8cc/0xfe8 kernel/workqueue.c:2439 kthread+0x254/0x2e0 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850 nvme nvme0: Removing after probe failure status: -19 nvme0n1: detected capacity change from 20971520 to 0 netdevsim netdevsim3 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim3 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim3 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim3 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 device hsr_slave_0 left promiscuous mode device hsr_slave_1 left promiscuous mode batman_adv: batadv0: Interface deactivated: batadv_slave_0 batman_adv: batadv0: Removing interface: batadv_slave_0 batman_adv: batadv0: Interface deactivated: batadv_slave_1 batman_adv: batadv0: Removing interface: batadv_slave_1 device bridge_slave_1 left promiscuous mode bridge0: port 2(bridge_slave_1) entered disabled state device bridge_slave_0 left promiscuous mode bridge0: port 1(bridge_slave_0) entered disabled state device veth1_macvtap left promiscuous mode device veth0_macvtap left promiscuous mode device veth1_vlan left promiscuous mode device veth0_vlan left promiscuous mode team0 (unregistering): Port device team_slave_1 removed bond0 (unregistering): (slave bond_slave_1): Releasing backup interface bond0 (unregistering): (slave bond_slave_0): Releasing backup interface bond0 (unregistering): Released all slaves