INFO: task kworker/u4:8:10327 blocked for more than 143 seconds. Not tainted 5.15.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:8 state:D stack:25744 pid:10327 ppid: 2 flags:0x00004000 Workqueue: nbd-del nbd_dev_remove_work Call Trace: context_switch kernel/sched/core.c:4969 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6250 schedule+0xd2/0x260 kernel/sched/core.c:6323 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: 1 lock held by khungtaskd/27: #0: ffffffff8bb83b60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 4 locks held by kworker/u4:4/942: #0: ffff8880159ca938 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880159ca938 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff8880159ca938 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff8880159ca938 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline] #0: ffff8880159ca938 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline] #0: ffff8880159ca938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269 #1: ffffc9000438fdb0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273 #2: ffffffff8d2fe210 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xb00 net/core/net_namespace.c:555 #3: ffff888038f6d2d0 (&wg->device_update_lock){+.+.}-{3:3}, at: wg_destruct+0x14b/0x430 drivers/net/wireguard/device.c:229 1 lock held by in:imklog/6215: #0: ffff888022cebc70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 2 locks held by kworker/u4:8/10327: #0: ffff88801a93f938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88801a93f938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff88801a93f938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff88801a93f938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline] #0: ffff88801a93f938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline] #0: ffff88801a93f938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269 #1: ffffc90002b8fdb0 ((work_completion)(&nbd->remove_work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273 2 locks held by kworker/1:15/11219: 3 locks held by kworker/1:18/11222: #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269 #1: ffffc9000af07db0 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273 #2: ffffffff8bb8cee8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #2: ffffffff8bb8cee8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d5/0x620 kernel/rcu/tree_exp.h:836 2 locks held by syz-executor.2/21654: #0: ffffffff8d311968 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d311968 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3be/0xb80 net/core/rtnetlink.c:5568 #1: ffffffff8bb8cee8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #1: ffffffff8bb8cee8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d5/0x620 kernel/rcu/tree_exp.h:836 1 lock held by syz-executor.3/21656: #0: ffffffff8d311968 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d311968 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3be/0xb80 net/core/rtnetlink.c:5568 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.0-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: 56 Comm: kworker/u4:3 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: 0x0 (bond0) RIP: 0010:lookup_object lib/debugobjects.c:198 [inline] RIP: 0010:debug_object_deactivate lib/debugobjects.c:737 [inline] RIP: 0010:debug_object_deactivate+0x14f/0x300 lib/debugobjects.c:723 Code: ed 74 44 49 bc 00 00 00 00 00 fc ff df 48 8d 7d 18 83 c3 01 48 89 f8 48 c1 e8 03 42 80 3c 20 00 0f 85 1e 01 00 00 4c 3b 7d 18 <74> 74 48 89 e8 48 c1 e8 03 42 80 3c 20 00 0f 85 22 01 00 00 48 8b RSP: 0018:ffffc90001a3fc38 EFLAGS: 00000087 RAX: 1ffff11003a172c7 RBX: 0000000000000001 RCX: ffffffff815d6e70 RDX: 1ffffffff20d7a76 RSI: 0000000000000016 RDI: ffff88801d0b9638 RBP: ffff88801d0b9620 R08: ffffffff906bd3a0 R09: 0000000000000003 R10: fffff52000347f75 R11: 0000000000000000 R12: dffffc0000000000 R13: ffffffff89ab2ee0 R14: 1ffff92000347f89 R15: ffff8880194130f8 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f90c725d080 CR3: 000000000b88e000 CR4: 0000000000350ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: debug_work_deactivate kernel/workqueue.c:514 [inline] process_one_work+0x399/0x1690 kernel/workqueue.c:2228 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: ed in (%dx),%eax 1: 74 44 je 0x47 3: 49 bc 00 00 00 00 00 movabs $0xdffffc0000000000,%r12 a: fc ff df d: 48 8d 7d 18 lea 0x18(%rbp),%rdi 11: 83 c3 01 add $0x1,%ebx 14: 48 89 f8 mov %rdi,%rax 17: 48 c1 e8 03 shr $0x3,%rax 1b: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) 20: 0f 85 1e 01 00 00 jne 0x144 26: 4c 3b 7d 18 cmp 0x18(%rbp),%r15 * 2a: 74 74 je 0xa0 <-- trapping instruction 2c: 48 89 e8 mov %rbp,%rax 2f: 48 c1 e8 03 shr $0x3,%rax 33: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) 38: 0f 85 22 01 00 00 jne 0x160 3e: 48 rex.W 3f: 8b .byte 0x8b