INFO: task kworker/u4:3:197 blocked for more than 140 seconds. Not tainted 4.14.165-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:3 D25800 197 2 0x80000000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x7b8/0x1cd0 kernel/sched/core.c:3384 schedule+0x92/0x1c0 kernel/sched/core.c:3428 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 netdev_run_todo+0x1fa/0x770 net/core/dev.c:7909 rtnl_unlock+0xe/0x10 net/core/rtnetlink.c:106 ip_tunnel_delete_net+0x278/0x330 net/ipv4/ip_tunnel.c:1086 vti_exit_net+0x11b/0x1f0 net/ipv4/ip_vti.c:499 ops_exit_list.isra.0+0xaa/0x150 net/core/net_namespace.c:142 cleanup_net+0x3ba/0x870 net/core/net_namespace.c:484 process_one_work+0x863/0x1600 kernel/workqueue.c:2114 worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248 kthread+0x319/0x430 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 INFO: task kworker/0:3:7336 blocked for more than 140 seconds. Not tainted 4.14.165-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:3 D26880 7336 2 0x80000000 Workqueue: events linkwatch_event Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x7b8/0x1cd0 kernel/sched/core.c:3384 schedule+0x92/0x1c0 kernel/sched/core.c:3428 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 linkwatch_event+0xe/0x60 net/core/link_watch.c:236 process_one_work+0x863/0x1600 kernel/workqueue.c:2114 worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248 kthread+0x319/0x430 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Showing all locks held in the system: 4 locks held by kworker/u4:3/197: #0: ("%s""netns"){+.+.}, at: [] work_static include/linux/workqueue.h:199 [inline] #0: ("%s""netns"){+.+.}, at: [] set_work_data kernel/workqueue.c:619 [inline] #0: ("%s""netns"){+.+.}, at: [] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ("%s""netns"){+.+.}, at: [] process_one_work+0x76e/0x1600 kernel/workqueue.c:2085 #1: (net_cleanup_work){+.+.}, at: [] process_one_work+0x7ab/0x1600 kernel/workqueue.c:2089 #2: (net_mutex){+.+.}, at: [] cleanup_net+0x11c/0x870 net/core/net_namespace.c:450 #3: (rtnl_mutex){+.+.}, at: [] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 1 lock held by khungtaskd/1059: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4544 1 lock held by rsyslogd/7154: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0xab/0xd0 fs/file.c:769 2 locks held by getty/7277: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156 2 locks held by getty/7278: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156 2 locks held by getty/7279: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156 2 locks held by getty/7280: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156 2 locks held by getty/7281: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156 2 locks held by getty/7282: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156 2 locks held by getty/7283: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156 3 locks held by kworker/0:3/7336: #0: ("events"){+.+.}, at: [] work_static include/linux/workqueue.h:199 [inline] #0: ("events"){+.+.}, at: [] set_work_data kernel/workqueue.c:619 [inline] #0: ("events"){+.+.}, at: [] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ("events"){+.+.}, at: [] process_one_work+0x76e/0x1600 kernel/workqueue.c:2085 #1: ((linkwatch_work).work){+.+.}, at: [] process_one_work+0x7ab/0x1600 kernel/workqueue.c:2089 #2: (rtnl_mutex){+.+.}, at: [] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 3 locks held by kworker/1:1/2269: #0: ("%s"("ipv6_addrconf")){+.+.}, at: [] work_static include/linux/workqueue.h:199 [inline] #0: ("%s"("ipv6_addrconf")){+.+.}, at: [] set_work_data kernel/workqueue.c:619 [inline] #0: ("%s"("ipv6_addrconf")){+.+.}, at: [] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ("%s"("ipv6_addrconf")){+.+.}, at: [] process_one_work+0x76e/0x1600 kernel/workqueue.c:2085 #1: ((addr_chk_work).work){+.+.}, at: [] process_one_work+0x7ab/0x1600 kernel/workqueue.c:2089 #2: (rtnl_mutex){+.+.}, at: [] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 1 lock held by syz-executor.5/2271: #0: (kernfs_mutex){+.+.}, at: [] kernfs_dop_revalidate+0x96/0x390 fs/kernfs/dir.c:570 1 lock held by syz-executor.3/2272: #0: (kernfs_mutex){+.+.}, at: [] kernfs_iop_permission+0x55/0xa0 fs/kernfs/inode.c:301 1 lock held by syz-executor.2/2273: #0: (kernfs_mutex){+.+.}, at: [] kernfs_iop_permission+0x55/0xa0 fs/kernfs/inode.c:301 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1059 Comm: khungtaskd Not tainted 4.14.165-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x142/0x197 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x94 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x141/0x189 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:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5e7/0xb90 kernel/hung_task.c:274 kthread+0x319/0x430 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 2232 Comm: syz-executor.0 Not tainted 4.14.165-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff888070a56000 task.stack: ffff888071088000 RIP: 0010:perf_prepare_sample+0x77/0x1350 kernel/events/core.c:6127 RSP: 0018:ffff8880aec07570 EFLAGS: 00000046 RAX: 1ffff110131150c5 RBX: ffff8880aec07648 RCX: ffff8880aec07b58 RDX: 0000000000010100 RSI: ffff8880aec07780 RDI: ffff8880988a8628 RBP: ffff8880aec07610 R08: 0000000000000000 R09: ffff888070a56940 R10: ffff888070a56920 R11: ffff888070a56000 R12: ffff8880aec07780 R13: ffff8880988a8540 R14: dffffc0000000000 R15: ffff8880aec07648 FS: 00007fb42d598700(0000) GS:ffff8880aec00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c42eb81000 CR3: 0000000072228000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __perf_event_output kernel/events/core.c:6259 [inline] perf_event_output_forward+0xe7/0x200 kernel/events/core.c:6277 __perf_event_overflow+0x11e/0x330 kernel/events/core.c:7515 perf_swevent_hrtimer+0x220/0x350 kernel/events/core.c:8725 __run_hrtimer kernel/time/hrtimer.c:1223 [inline] __hrtimer_run_queues+0x270/0xbc0 kernel/time/hrtimer.c:1287 hrtimer_interrupt+0x1d8/0x5d0 kernel/time/hrtimer.c:1321 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline] smp_apic_timer_interrupt+0x11c/0x5e0 arch/x86/kernel/apic/apic.c:1100 apic_timer_interrupt+0x96/0xa0 arch/x86/entry/entry_64.S:792 RIP: 0010:bytes_is_nonzero mm/kasan/kasan.c:167 [inline] RIP: 0010:memory_is_nonzero mm/kasan/kasan.c:184 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/kasan.c:210 [inline] RIP: 0010:memory_is_poisoned mm/kasan/kasan.c:241 [inline] RIP: 0010:check_memory_region_inline mm/kasan/kasan.c:257 [inline] RIP: 0010:check_memory_region+0x112/0x190 mm/kasan/kasan.c:267 RSP: 0018:ffff8880aec07c08 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10 RAX: ffffed1012cef782 RBX: ffffed1012cef783 RCX: ffffffff852cd816 RDX: 0000000000000000 RSI: 0000000000000006 RDI: ffff88809677bc10 RBP: ffff8880aec07c20 R08: 1ffff11012cef782 R09: ffffed1012cef783 R10: ffffed1012cef782 R11: ffff88809677bc15 R12: ffffed1012cef782 R13: ffff88806d0a9588 R14: ffff88809677bc10 R15: ffff8880932177a8 memcpy+0x24/0x50 mm/kasan/kasan.c:302 memcpy include/linux/string.h:347 [inline] eth_header+0xe6/0x1d0 net/ethernet/eth.c:99 dev_hard_header include/linux/netdevice.h:2721 [inline] send_hsr_supervision_frame+0x37c/0xec0 net/hsr/hsr_device.c:279 hsr_announce+0xf5/0x340 net/hsr/hsr_device.c:348 call_timer_fn+0x161/0x670 kernel/time/timer.c:1279 expire_timers kernel/time/timer.c:1318 [inline] __run_timers kernel/time/timer.c:1636 [inline] __run_timers kernel/time/timer.c:1604 [inline] run_timer_softirq+0x5b7/0x1520 kernel/time/timer.c:1649 __do_softirq+0x244/0x9a0 kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x160/0x1b0 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:648 [inline] smp_apic_timer_interrupt+0x146/0x5e0 arch/x86/kernel/apic/apic.c:1102 apic_timer_interrupt+0x96/0xa0 arch/x86/entry/entry_64.S:792 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:779 [inline] RIP: 0010:kmem_cache_free+0xb0/0x2b0 mm/slab.c:3759 RSP: 0018:ffff88807108f470 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff10 RAX: 0000000000000007 RBX: ffff8880a0674460 RCX: 1ffff1100e14ad19 RDX: 0000000000000000 RSI: ffff888070a568a8 RDI: 0000000000000286 RBP: ffff88807108f490 R08: ffff888070a56000 R09: ffff888070a568c8 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880aa9e9840 R13: 0000000000000286 R14: ffffffff81ac5bdb R15: 0000000000000000 kernfs_put fs/kernfs/dir.c:544 [inline] kernfs_put+0x30b/0x490 fs/kernfs/dir.c:506 __kernfs_remove fs/kernfs/dir.c:1315 [inline] __kernfs_remove+0x382/0x7e0 fs/kernfs/dir.c:1252 kernfs_remove_by_name_ns+0x5a/0x90 fs/kernfs/dir.c:1487 kernfs_remove_by_name include/linux/kernfs.h:529 [inline] remove_files.isra.0+0x7b/0x190 fs/sysfs/group.c:29 sysfs_remove_group+0xb2/0x140 fs/sysfs/group.c:245 sysfs_remove_groups fs/sysfs/group.c:269 [inline] sysfs_remove_groups+0x61/0xa4 fs/sysfs/group.c:261 device_remove_groups drivers/base/core.c:1048 [inline] device_remove_attrs+0xb4/0x160 drivers/base/core.c:1230 device_del+0x3c6/0xaa0 drivers/base/core.c:2058 netdev_unregister_kobject+0x184/0x1d0 net/core/net-sysfs.c:1565 rollback_registered_many+0x694/0xb60 net/core/dev.c:7238 rollback_registered+0xdd/0x180 net/core/dev.c:7256 unregister_netdevice_queue net/core/dev.c:8249 [inline] unregister_netdevice_queue+0x1ae/0x230 net/core/dev.c:8242 unregister_netdevice include/linux/netdevice.h:2442 [inline] __tun_detach+0xa8c/0xce0 drivers/net/tun.c:576 tun_detach drivers/net/tun.c:586 [inline] tun_chr_close+0x46/0x60 drivers/net/tun.c:2660 __fput+0x275/0x7a0 fs/file_table.c:210 ____fput+0x16/0x20 fs/file_table.c:244 task_work_run+0x114/0x190 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xa1a/0x2cd0 kernel/exit.c:858 do_group_exit+0x111/0x330 kernel/exit.c:955 get_signal+0x381/0x1cd0 kernel/signal.c:2413 do_signal+0x86/0x19a0 arch/x86/kernel/signal.c:814 exit_to_usermode_loop+0x15c/0x220 arch/x86/entry/common.c:160 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4bc/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45aff9 RSP: 002b:00007fb42d597c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: 0000000000000004 RBX: 00007fb42d5986d4 RCX: 000000000045aff9 RDX: 0000000000000048 RSI: 0000000020000200 RDI: 0000000000000005 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000064 R14: 00000000004c173d R15: 000000000075bf2c Code: 45 a8 00 09 6e 81 c7 00 f1 f1 f1 f1 c7 40 04 00 f3 f3 f3 e8 2c 1a ef ff 49 8d bd e8 00 00 00 48 89 f8 48 c1 e8 03 42 80 3c 30 00 <0f> 85 cf 10 00 00 49 8b 85 e8 00 00 00 48 89 da 48 c1 ea 03 48