INFO: task kworker/u4:4:3012 blocked for more than 140 seconds. Not tainted 4.19.211-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:4 D25184 3012 2 0x80000000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 schedule_timeout+0x92d/0xfe0 kernel/time/timer.c:1794 audit: type=1326 audit(1669755753.585:59): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=21360 comm="syz-executor.2" exe="/root/syz-executor.2" sig=31 arch=c000003e syscall=202 compat=0 ip=0x7fe7bf3df0d9 code=0x0 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common+0x29c/0x470 kernel/sched/completion.c:115 flush_workqueue+0x40b/0x13e0 kernel/workqueue.c:2713 flush_scheduled_work include/linux/workqueue.h:599 [inline] tipc_exit_net+0x38/0x60 net/tipc/core.c:100 ops_exit_list+0xa5/0x150 net/core/net_namespace.c:153 cleanup_net+0x3b4/0x8b0 net/core/net_namespace.c:554 process_one_work+0x864/0x1570 kernel/workqueue.c:2153 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Showing all locks held in the system: 2 locks held by kworker/0:0/5: #0: 00000000328fe560 ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000b0f4b712 ((work_completion)(&m->rq)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 2 locks held by kworker/u4:2/54: #0: 00000000e499fe90 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1826 [inline] #0: 00000000e499fe90 (&rq->lock){-.-.}, at: __schedule+0x1f9/0x2040 kernel/sched/core.c:3455 #1: 0000000067ff2a01 ((work_completion)(&sub_info->work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 1 lock held by khungtaskd/1570: #0: 0000000036af0815 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 3 locks held by kworker/u4:4/3012: #0: 00000000bf459339 ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 000000001151c232 (net_cleanup_work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 00000000610e3648 (pernet_ops_rwsem){++++}, at: cleanup_net+0xa8/0x8b0 net/core/net_namespace.c:521 2 locks held by kworker/1:2/3407: #0: 00000000328fe560 ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 print_req_error: 320 callbacks suppressed print_req_error: I/O error, dev loop4, sector 105 print_req_error: I/O error, dev loop4, sector 34 print_req_error: I/O error, dev loop4, sector 34 buffer_io_error: 278 callbacks suppressed Buffer I/O error on dev loop4p1, logical block 0, async page read print_req_error: I/O error, dev loop4, sector 36 Buffer I/O error on dev loop4p1, logical block 1, async page read print_req_error: I/O error, dev loop4, sector 38 Buffer I/O error on dev loop4p1, logical block 2, async page read print_req_error: I/O error, dev loop4, sector 40 Buffer I/O error on dev loop4p1, logical block 3, async page read print_req_error: I/O error, dev loop4, sector 105 Buffer I/O error on dev loop4p3, logical block 8, async page read #1: 000000001c3e43a1 ((work_completion)(&m->rq)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 print_req_error: I/O error, dev loop4, sector 106 Buffer I/O error on dev loop4p3, logical block 9, async page read print_req_error: I/O error, dev loop4, sector 107 Buffer I/O error on dev loop4p3, logical block 10, async page read print_req_error: I/O error, dev loop4, sector 108 Buffer I/O error on dev loop4p3, logical block 11, async page read Buffer I/O error on dev loop4p3, logical block 12, async page read Buffer I/O error on dev loop4p3, logical block 13, async page read 2 locks held by kworker/0:2/3688: #0: 000000002a9e6f28 ((wq_completion)"rcu_gp"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 000000002a62b3c0 ((work_completion)(&rew.rew_work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 1 lock held by in:imklog/7774: #0: 000000008d106e72 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 2 locks held by syz-executor.0/21402: #0: 000000005dcf32d8 (&sb->s_type->i_mutex_key#13){+.+.}, at: inode_lock include/linux/fs.h:748 [inline] #0: 000000005dcf32d8 (&sb->s_type->i_mutex_key#13){+.+.}, at: __sock_release+0x86/0x2a0 net/socket.c:598 #1: 00000000dc040627 (rcu_preempt_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #1: 00000000dc040627 (rcu_preempt_state.exp_mutex){+.+.}, at: _synchronize_rcu_expedited+0x256/0x6f0 kernel/rcu/tree_exp.h:667 2 locks held by syz-executor.5/21403: #0: 00000000b9d7abd9 (&sb->s_type->i_mutex_key#13){+.+.}, at: inode_lock include/linux/fs.h:748 [inline] #0: 00000000b9d7abd9 (&sb->s_type->i_mutex_key#13){+.+.}, at: __sock_release+0x86/0x2a0 net/socket.c:598 #1: 00000000dc040627 (rcu_preempt_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #1: 00000000dc040627 (rcu_preempt_state.exp_mutex){+.+.}, at: _synchronize_rcu_expedited+0x4dc/0x6f0 kernel/rcu/tree_exp.h:667 1 lock held by syz-executor.4/21433: #0: 000000005a4e0a30 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1826 [inline] #0: 000000005a4e0a30 (&rq->lock){-.-.}, at: __schedule+0x1f9/0x2040 kernel/sched/core.c:3455 2 locks held by syz-executor.4/21442: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1570 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x991/0xe60 kernel/hung_task.c:287 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 9409 Comm: kworker/u4:6 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Workqueue: bat_events batadv_nc_worker RIP: 0010:arch_local_save_flags arch/x86/include/asm/paravirt.h:784 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/paravirt.h:806 [inline] RIP: 0010:lock_release+0xd1/0x8b0 kernel/locking/lockdep.c:3923 Code: 82 f1 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 c3 06 00 00 48 83 3d c6 37 a6 08 00 0f 84 1b 05 00 00 9c <58> 0f 1f 44 00 00 48 ba 00 00 00 00 00 fc ff df 48 89 04 24 48 c7 RSP: 0018:ffff88805604fbf8 EFLAGS: 00000286 RAX: 1ffffffff13e3050 RBX: ffff8880a5d88300 RCX: ffffffff87d8f371 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff8880a5d88b84 RBP: ffffffff89f85fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1100ac09f83 R13: ffffffff87d8f075 R14: 0000000000000110 R15: ffff8880a4464000 FS: 0000000000000000(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9053e08000 CR3: 0000000055b2c000 CR4: 00000000003426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: