INFO: task kworker/u16:0:8 blocked for more than 143 seconds. Not tainted 5.4.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u16:0 D26392 8 2 0x80004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x8e1/0x1f30 kernel/sched/core.c:4081 schedule+0xdc/0x2b0 kernel/sched/core.c:4155 schedule_timeout+0x717/0xc50 kernel/time/timer.c:1871 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136 __wait_rcu_gp+0x225/0x2f0 kernel/rcu/update.c:374 synchronize_rcu.part.0+0xcf/0xe0 kernel/rcu/tree.c:2768 synchronize_rcu+0x27/0xa0 kernel/rcu/tree.c:2769 lockdep_unregister_key+0x336/0x4c0 kernel/locking/lockdep.c:5199 netdev_unregister_lockdep_key net/core/dev.c:9174 [inline] free_netdev+0x2f7/0x470 net/core/dev.c:9835 netdev_run_todo+0x64a/0x7d0 net/core/dev.c:9580 rtnl_unlock+0xe/0x10 net/core/rtnetlink.c:112 ip_tunnel_delete_nets+0x42a/0x600 net/ipv4/ip_tunnel.c:1114 erspan_exit_batch_net+0x23/0x30 net/ipv4/ip_gre.c:1600 ops_exit_list.isra.0+0x10c/0x160 net/core/net_namespace.c:175 cleanup_net+0x538/0xaf0 net/core/net_namespace.c:597 process_one_work+0x9af/0x1740 kernel/workqueue.c:2264 worker_thread+0x98/0xe40 kernel/workqueue.c:2410 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Showing all locks held in the system: 3 locks held by kworker/u16:0/8: #0: ffff88802c7e4d28 ((wq_completion)netns){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff88802c7e4d28 ((wq_completion)netns){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88802c7e4d28 ((wq_completion)netns){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff88802c7e4d28 ((wq_completion)netns){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff88802c7e4d28 ((wq_completion)netns){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff88802c7e4d28 ((wq_completion)netns){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff88802c7e4d28 ((wq_completion)netns){+.+.}, at: process_one_work+0x88b/0x1740 kernel/workqueue.c:2235 #1: ffff88802c457dc0 (net_cleanup_work){+.+.}, at: process_one_work+0x8c1/0x1740 kernel/workqueue.c:2239 #2: ffffffff8a087e08 (pernet_ops_rwsem){++++}, at: cleanup_net+0xae/0xaf0 net/core/net_namespace.c:559 1 lock held by khungtaskd/1114: #0: ffffffff895a4080 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5334 2 locks held by rsyslogd/7835: #0: ffff88802a600160 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 #1: ffff88802d437398 (&rq->lock){-.-.}, at: newidle_balance+0xa28/0xe80 kernel/sched/fair.c:10166 2 locks held by getty/7959: #0: ffff88801ba63090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000401e2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/7960: #0: ffff888021215090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900040262e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/7961: #0: ffff88802252e090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900040322e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/7962: #0: ffff88802bfaf090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900040162e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/7963: #0: ffff888025a83090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000403a2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/7964: #0: ffff888020f19090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900040362e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/7965: #0: ffff8880103be090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000400a2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 4 locks held by syz-executor.0/17790: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1114 Comm: khungtaskd Not tainted 5.4.0-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xb11/0x10c0 kernel/hung_task.c:289 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0,2-3: NMI backtrace for cpu 2 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60 NMI backtrace for cpu 3 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.075 msecs NMI backtrace for cpu 0 CPU: 0 PID: 17790 Comm: syz-executor.0 Not tainted 5.4.0-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 RIP: 0010:apic_timer_interrupt+0x0/0x20 arch/x86/entry/entry_64.S:829 Code: 31 ff fc e8 57 50 40 f9 48 89 e7 e8 ca 93 40 f9 e8 2e 50 40 f9 e9 c5 f2 ff ff c3 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <68> 13 ff ff ff e8 76 f1 ff ff e8 61 2e 00 00 e9 6b f2 ff ff 66 90 RSP: 0018:ffff88802d2094c8 EFLAGS: 00000082 RAX: 1ffffffff12a668b RBX: ffff88806e684740 RCX: ffffffff815a6e80 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: 0000000000000282 RBP: ffff88802d209540 R08: 1ffffffff15d299c R09: fffffbfff15d299d R10: ffff88806e685050 R11: ffff88806e684740 R12: ffffffff895a4080 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000002 FS: 00007f66cbbe7700(0000) GS:ffff88802d200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 000000005d267000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:208 [inline] rcu_read_lock include/linux/rcupdate.h:617 [inline] is_bpf_text_address+0x39/0x160 kernel/bpf/core.c:707 kernel_text_address+0x73/0xf0 kernel/extable.c:149 __kernel_text_address+0xd/0x40 kernel/extable.c:104 unwind_get_return_address arch/x86/kernel/unwind_frame.c:19 [inline] unwind_get_return_address+0x61/0xa0 arch/x86/kernel/unwind_frame.c:14 arch_stack_walk+0x97/0xf0 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0xac/0xe0 kernel/stacktrace.c:123 save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_kmalloc mm/kasan/common.c:510 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:483 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:518 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc mm/slab.c:3319 [inline] kmem_cache_alloc+0x121/0x710 mm/slab.c:3483 dst_alloc+0x10e/0x200 net/core/dst.c:93 ip6_dst_alloc+0x34/0xa0 net/ipv6/route.c:353 icmp6_dst_alloc+0x69/0x4a0 net/ipv6/route.c:3130 ndisc_send_skb+0xfb7/0x1490 net/ipv6/ndisc.c:485 ndisc_send_rs+0x134/0x720 net/ipv6/ndisc.c:699 addrconf_rs_timer+0x30f/0x6e0 net/ipv6/addrconf.c:3879 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1404 expire_timers kernel/time/timer.c:1449 [inline] __run_timers kernel/time/timer.c:1773 [inline] __run_timers kernel/time/timer.c:1740 [inline] run_timer_softirq+0x6c3/0x1790 kernel/time/timer.c:1786 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1137 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x4f/0x80 kernel/locking/spinlock.c:199 Code: c0 68 34 53 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 33 48 83 3d 12 2a 99 01 00 74 20 fb 66 0f 1f 44 00 00 01 00 00 00 e8 e7 6b 96 f9 65 8b 05 18 14 48 78 85 c0 74 06 41 RSP: 0018:ffff88805f0278d8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff12a668d RBX: ffff88806e684740 RCX: 0000000000000006 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff88806e684fd4 RBP: ffff88805f0278e0 R08: 1ffffffff15d29bb R09: fffffbfff15d29bc R10: fffffbfff15d29bb R11: ffffffff8ae94ddf R12: ffff88802d237380 R13: ffffffff8947a1c0 R14: ffff8880246162c0 R15: 0000000000000000 finish_lock_switch kernel/sched/core.c:3124 [inline] finish_task_switch+0x147/0x750 kernel/sched/core.c:3224 context_switch kernel/sched/core.c:3388 [inline] __schedule+0x8e9/0x1f30 kernel/sched/core.c:4081 preempt_schedule_common+0x4f/0xe0 kernel/sched/core.c:4236 preempt_schedule+0x4b/0x60 kernel/sched/core.c:4261 ___preempt_schedule+0x16/0x18 arch/x86/entry/thunk_64.S:50 smp_call_function_single+0x410/0x480 kernel/smp.c:313 task_function_call+0xe9/0x180 kernel/events/core.c:114 perf_install_in_context+0x308/0x5a0 kernel/events/core.c:2746 __do_sys_perf_event_open+0x1cbc/0x2c70 kernel/events/core.c:11543 __se_sys_perf_event_open kernel/events/core.c:11151 [inline] __x64_sys_perf_event_open+0xbe/0x150 kernel/events/core.c:11151 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a759 Code: bd b1 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 8b b1 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f66cbbe6c88 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 000000000071bf00 RCX: 000000000045a759 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 000000002001d000 RBP: 0000000000000005 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 00007f66cbbe76d4 R13: 00000000004aec2b R14: 00000000006f1ca8 R15: 00000000ffffffff