INFO: task kworker/u4:3:145 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/u4:3 D25184 145 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 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: 3 locks held by kworker/u4:3/145: #0: 00000000c6b97db9 ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000edcaf452 (net_cleanup_work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 00000000b979a1a8 (pernet_ops_rwsem){++++}, at: cleanup_net+0xa8/0x8b0 net/core/net_namespace.c:521 1 lock held by khungtaskd/1571: #0: 0000000083560478 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 1 lock held by in:imklog/7812: #0: 00000000dbf2dc86 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 3 locks held by kworker/1:4/8168: #0: 00000000081fb759 ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000b92aa33c ((work_completion)(&smc->tcp_listen_work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 000000001f6aefbe (&smc->clcsock_release_lock){+.+.}, at: smc_clcsock_accept net/smc/af_smc.c:843 [inline] #2: 000000001f6aefbe (&smc->clcsock_release_lock){+.+.}, at: smc_tcp_listen_work+0x191/0xce0 net/smc/af_smc.c:1314 3 locks held by kworker/0:3/9033: #0: 00000000081fb759 ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 000000007b2f8e1e ((work_completion)(&smc->tcp_listen_work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 0000000091c552a8 (&smc->clcsock_release_lock){+.+.}, at: smc_clcsock_accept net/smc/af_smc.c:843 [inline] #2: 0000000091c552a8 (&smc->clcsock_release_lock){+.+.}, at: smc_tcp_listen_work+0x191/0xce0 net/smc/af_smc.c:1314 2 locks held by kworker/u4:11/12158: 3 locks held by kworker/1:0/32093: #0: 00000000081fb759 ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000ca7eb1b7 ((work_completion)(&smc->tcp_listen_work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 00000000235a4c30 (&smc->clcsock_release_lock){+.+.}, at: smc_clcsock_accept net/smc/af_smc.c:843 [inline] #2: 00000000235a4c30 (&smc->clcsock_release_lock){+.+.}, at: smc_tcp_listen_work+0x191/0xce0 net/smc/af_smc.c:1314 3 locks held by kworker/1:5/32094: #0: 00000000081fb759 ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 0000000086aa0584 ((work_completion)(&smc->tcp_listen_work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 000000008cf28bb7 (&smc->clcsock_release_lock){+.+.}, at: smc_clcsock_accept net/smc/af_smc.c:843 [inline] #2: 000000008cf28bb7 (&smc->clcsock_release_lock){+.+.}, at: smc_tcp_listen_work+0x191/0xce0 net/smc/af_smc.c:1314 3 locks held by kworker/0:0/9337: #0: 00000000081fb759 ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000b5e9ffe2 ((work_completion)(&smc->tcp_listen_work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 0000000015823657 (&smc->clcsock_release_lock){+.+.}, at: smc_clcsock_accept net/smc/af_smc.c:843 [inline] #2: 0000000015823657 (&smc->clcsock_release_lock){+.+.}, at: smc_tcp_listen_work+0x191/0xce0 net/smc/af_smc.c:1314 3 locks held by kworker/1:1/9601: #0: 00000000081fb759 ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000ecb8be95 ((work_completion)(&smc->tcp_listen_work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 00000000b2695e6d (&smc->clcsock_release_lock){+.+.}, at: smc_clcsock_accept net/smc/af_smc.c:843 [inline] #2: 00000000b2695e6d (&smc->clcsock_release_lock){+.+.}, at: smc_tcp_listen_work+0x191/0xce0 net/smc/af_smc.c:1314 5 locks held by syz-executor.0/21059: 2 locks held by syz-executor.5/21110: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1571 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023 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: 8162 Comm: syz-executor.4 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023 RIP: 0010:__sanitizer_cov_trace_pc+0x47/0x50 kernel/kcov.c:111 Code: 90 60 13 00 00 83 fa 02 75 20 48 8b 88 68 13 00 00 8b 80 64 13 00 00 48 8b 11 48 83 c2 01 48 39 d0 76 07 48 89 34 d1 48 89 11 0f 1f 84 00 00 00 00 00 49 89 f1 49 89 fa 65 48 8b 34 25 c0 df RSP: 0018:ffff88809c76f9d0 EFLAGS: 00000093 RAX: ffff8880a1096680 RBX: 000000000002be80 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff83772075 RDI: ffffffff89f88650 RBP: dffffc0000000000 R08: 0000000000000000 R09: ffffed101740455a R10: ffff8880ba022ad3 R11: ffff8880ba02bc50 R12: ffffffff89f88280 R13: ffff8880a1096758 R14: 0000000000000009 R15: ffff8880a1096680 FS: 000055555690d400(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb1ed7351b8 CR3: 000000009fc3e000 CR4: 00000000003406f0 DR0: 0000000000000001 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: debug_smp_processor_id+0x5/0x20 lib/smp_processor_id.c:56 rcu_lockdep_current_cpu_online kernel/rcu/tree.c:1078 [inline] rcu_lockdep_current_cpu_online+0xb2/0x1b0 kernel/rcu/tree.c:1068 rcu_read_lock_sched_held+0xd3/0x1d0 kernel/rcu/update.c:115 trace_sched_stat_runtime include/trace/events/sched.h:428 [inline] update_curr+0x5f3/0x870 kernel/sched/fair.c:857 dequeue_entity+0x1d/0x2800 kernel/sched/fair.c:4048 dequeue_task_fair+0x68/0x1b60 kernel/sched/fair.c:5241 __schedule+0x2d6/0x2040 kernel/sched/core.c:3467 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 freezable_schedule include/linux/freezer.h:172 [inline] do_nanosleep+0x264/0x6c0 kernel/time/hrtimer.c:1755 hrtimer_nanosleep+0x24d/0x570 kernel/time/hrtimer.c:1809 common_nsleep+0x23/0x30 kernel/time/posix-timers.c:1204 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1231 [inline] __se_sys_clock_nanosleep+0x261/0x360 kernel/time/posix-timers.c:1209 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f6f10086e21 Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 aa e7 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 e3 e7 ff ff 48 8b 04 24 eb 97 66 2e 0f 1f RSP: 002b:00007fffb8abc950 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 0000000000000f57 RCX: 00007f6f10086e21 RDX: 00007fffb8abc990 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fffb8abca1c R08: 0000000000000000 R09: 000001444aa7e853 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032 R13: 000000000013425f R14: 0000000000000000 R15: 00007fffb8abca80