INFO: task kworker/u4:5:8001 blocked for more than 143 seconds. Not tainted 5.16.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:5 state:D stack:24272 pid: 8001 ppid: 2 flags:0x00004000 Workqueue: nbd-del nbd_dev_remove_work Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6253 schedule+0xd2/0x260 kernel/sched/core.c:6326 blk_mq_freeze_queue_wait+0x112/0x160 block/blk-mq.c:178 del_gendisk+0x598/0x860 block/genhd.c:623 nbd_dev_remove+0x3c/0xf0 drivers/block/nbd.c:252 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Showing all locks held in the system: 2 locks held by kworker/u4:0/8: #0: ffff88801acac938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88801acac938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff88801acac938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff88801acac938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline] #0: ffff88801acac938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline] #0: ffff88801acac938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269 #1: ffffc90000cd7db0 ((work_completion)(&nbd->remove_work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273 1 lock held by khungtaskd/27: #0: ffffffff8bb83ae0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 2 locks held by kworker/u4:4/970: #0: ffff88801acac938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88801acac938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff88801acac938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff88801acac938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline] #0: ffff88801acac938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline] #0: ffff88801acac938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269 #1: ffffc90004d0fdb0 ((work_completion)(&nbd->remove_work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273 1 lock held by systemd-udevd/2969: 1 lock held by in:imklog/6245: #0: ffff88801a6b8870 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 2 locks held by kworker/u4:5/8001: #0: ffff88801acac938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88801acac938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff88801acac938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff88801acac938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline] #0: ffff88801acac938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline] #0: ffff88801acac938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269 #1: ffffc90016ae7db0 ((work_completion)(&nbd->remove_work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.16.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xc1d/0xf50 kernel/hung_task.c:295 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 30282 Comm: kworker/u4:13 Not tainted 5.16.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_purge_orig RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:132 [inline] RIP: 0010:__local_bh_enable_ip+0x5d/0x120 kernel/softirq.c:365 Code: 03 83 c0 03 0f b6 14 11 38 d0 7c 08 84 d2 0f 85 c5 00 00 00 8b 05 cf a7 4a 0c 85 c0 74 0b 65 8b 05 b8 7a bb 7e 85 c0 74 53 9c <58> fa f6 c4 02 75 5a 65 8b 05 25 70 bb 7e 25 00 ff 00 00 3d 00 02 RSP: 0018:ffffc900032efbd8 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000201 RCX: 1ffffffff1b234f1 RDX: 0000000000000000 RSI: 0000000000000201 RDI: ffffffff88eeb757 RBP: ffffffff88eeb757 R08: 0000000000000000 R09: ffff888072243d43 R10: ffffed100e4487a8 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff88802362cdd0 R14: ffff88804b080a00 R15: 00000000000000f5 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f430cf4c5d0 CR3: 000000000b88e000 CR4: 0000000000350ef0 Call Trace: spin_unlock_bh include/linux/spinlock.h:394 [inline] batadv_purge_orig_ref+0xeb7/0x1550 net/batman-adv/originator.c:1259 batadv_purge_orig+0x17/0x60 net/batman-adv/originator.c:1272 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 03 83 c0 03 0f b6 add -0x49f0fc40(%rbx),%eax 6: 14 11 adc $0x11,%al 8: 38 d0 cmp %dl,%al a: 7c 08 jl 0x14 c: 84 d2 test %dl,%dl e: 0f 85 c5 00 00 00 jne 0xd9 14: 8b 05 cf a7 4a 0c mov 0xc4aa7cf(%rip),%eax # 0xc4aa7e9 1a: 85 c0 test %eax,%eax 1c: 74 0b je 0x29 1e: 65 8b 05 b8 7a bb 7e mov %gs:0x7ebb7ab8(%rip),%eax # 0x7ebb7add 25: 85 c0 test %eax,%eax 27: 74 53 je 0x7c 29: 9c pushfq * 2a: 58 pop %rax <-- trapping instruction 2b: fa cli 2c: f6 c4 02 test $0x2,%ah 2f: 75 5a jne 0x8b 31: 65 8b 05 25 70 bb 7e mov %gs:0x7ebb7025(%rip),%eax # 0x7ebb705d 38: 25 00 ff 00 00 and $0xff00,%eax 3d: 3d .byte 0x3d 3e: 00 02 add %al,(%rdx)