INFO: task syz-executor.3:11064 can't die for more than 143 seconds. syz-executor.3 D28136 11064 9326 0x00000004 Call Trace: context_switch kernel/sched/core.c:2818 [inline] __schedule+0x755/0x1580 kernel/sched/core.c:3444 schedule+0xa8/0x270 kernel/sched/core.c:3508 __rwsem_down_write_failed_common+0x803/0xee0 kernel/locking/rwsem-xadd.c:601 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:633 __down_write kernel/locking/rwsem.h:227 [inline] down_write+0x93/0xa0 kernel/locking/rwsem.c:68 unregister_netdevice_notifier+0x7e/0x390 net/core/dev.c:1713 bcm_release+0x93/0x5e0 net/can/bcm.c:1525 __sock_release+0xce/0x2a0 net/socket.c:601 sock_close+0x1b/0x30 net/socket.c:1273 __fput+0x2ff/0x890 fs/file_table.c:280 ____fput+0x16/0x20 fs/file_table.c:313 task_work_run+0x145/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x280/0x2d0 arch/x86/entry/common.c:168 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x5a9/0x6a0 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x412fb1 Code: 80 3b 7c 0f 84 c7 02 00 00 c7 85 d0 00 00 00 00 00 00 00 48 8b 05 cf a6 24 00 49 8b 14 24 41 b9 cb 2a 44 00 48 89 ee 48 89 df <48> 85 c0 4c 0f 45 c8 45 31 c0 31 c9 e8 0e 5b 00 00 85 c0 41 89 c7 RSP: 002b:00007fff8c1816f0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000007 RCX: 0000000000412fb1 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006 RBP: 0000000000000001 R08: 00000000f57f668e R09: ffffffffffffffff R10: 00007fff8c1817d0 R11: 0000000000000293 R12: 000000000075c9a0 R13: 000000000075c9a0 R14: 00000000000468dd R15: 000000000075c07c INFO: task syz-executor.3:11064 blocked for more than 143 seconds. Not tainted 5.2.0-rc5-next-20190620 #19 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28136 11064 9326 0x00000004 Call Trace: context_switch kernel/sched/core.c:2818 [inline] __schedule+0x755/0x1580 kernel/sched/core.c:3444 schedule+0xa8/0x270 kernel/sched/core.c:3508 __rwsem_down_write_failed_common+0x803/0xee0 kernel/locking/rwsem-xadd.c:601 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:633 __down_write kernel/locking/rwsem.h:227 [inline] down_write+0x93/0xa0 kernel/locking/rwsem.c:68 unregister_netdevice_notifier+0x7e/0x390 net/core/dev.c:1713 bcm_release+0x93/0x5e0 net/can/bcm.c:1525 __sock_release+0xce/0x2a0 net/socket.c:601 sock_close+0x1b/0x30 net/socket.c:1273 __fput+0x2ff/0x890 fs/file_table.c:280 ____fput+0x16/0x20 fs/file_table.c:313 task_work_run+0x145/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x280/0x2d0 arch/x86/entry/common.c:168 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x5a9/0x6a0 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x412fb1 Code: 80 3b 7c 0f 84 c7 02 00 00 c7 85 d0 00 00 00 00 00 00 00 48 8b 05 cf a6 24 00 49 8b 14 24 41 b9 cb 2a 44 00 48 89 ee 48 89 df <48> 85 c0 4c 0f 45 c8 45 31 c0 31 c9 e8 0e 5b 00 00 85 c0 41 89 c7 RSP: 002b:00007fff8c1816f0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000007 RCX: 0000000000412fb1 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006 RBP: 0000000000000001 R08: 00000000f57f668e R09: ffffffffffffffff R10: 00007fff8c1817d0 R11: 0000000000000293 R12: 000000000075c9a0 R13: 000000000075c9a0 R14: 00000000000468dd R15: 000000000075c07c Showing all locks held in the system: 1 lock held by khungtaskd/1043: #0: 00000000292dfbda (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5262 3 locks held by kworker/u4:4/3060: 1 lock held by rsyslogd/9188: #0: 00000000ee9daaf9 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/9278: #0: 00000000e41a5c80 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000965b5193 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9279: #0: 00000000845cd81b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000086eca1a7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9280: #0: 0000000095a772f7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000d1806949 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9281: #0: 0000000090a52d2e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000557db3e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9282: #0: 00000000a1a17a7f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000008d1f3b80 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9283: #0: 0000000069a11f6f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000e3e95d4d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9284: #0: 00000000c54e24bc (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000007ea8cd9f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.3/11064: #0: 000000002153fc3f (&sb->s_type->i_mutex_key#11){+.+.}, at: inode_lock include/linux/fs.h:778 [inline] #0: 000000002153fc3f (&sb->s_type->i_mutex_key#11){+.+.}, at: __sock_release+0x89/0x2a0 net/socket.c:600 #1: 0000000079602dec (pernet_ops_rwsem){++++}, at: unregister_netdevice_notifier+0x7e/0x390 net/core/dev.c:1713 1 lock held by syz-executor.1/11077: #0: 0000000079602dec (pernet_ops_rwsem){++++}, at: copy_net_ns+0x1c0/0x340 net/core/net_namespace.c:452 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1043 Comm: khungtaskd Not tainted 5.2.0-rc5-next-20190620 #19 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x22f/0x27f 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:249 [inline] watchdog+0xc54/0x1320 kernel/hung_task.c:333 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3060 Comm: kworker/u4:4 Not tainted 5.2.0-rc5-next-20190620 #19 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net RIP: 0010:__lock_acquire+0x1263/0x4680 kernel/locking/lockdep.c:3758 Code: 41 5d 41 5e 41 5f 5d c3 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 80 3c 02 00 0f 85 90 24 00 00 49 81 3e 60 36 e0 89 <0f> 84 61 ee ff ff 83 fe 01 0f 87 64 ee ff ff 48 b8 00 00 00 00 00 RSP: 0018:ffff88809f51f948 EFLAGS: 00000006 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 1ffffffff118c4f1 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffff88809f51fa68 R08: 0000000000000001 R09: 0000000000000001 R10: fffffbfff13429cf R11: ffff88809f514400 R12: ffffffff88c62788 R13: 0000000000000000 R14: ffffffff88c62788 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 0000000086ab7000 CR4: 00000000001426e0 Call Trace: lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4418 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:338 [inline] nf_conntrack_lock+0x17/0x70 net/netfilter/nf_conntrack_core.c:95 get_next_corpse net/netfilter/nf_conntrack_core.c:2008 [inline] nf_ct_iterate_cleanup+0x1d7/0x4e0 net/netfilter/nf_conntrack_core.c:2042 nf_conntrack_cleanup_net_list+0x7a/0x240 net/netfilter/nf_conntrack_core.c:2229 nf_conntrack_pernet_exit+0x159/0x1a0 net/netfilter/nf_conntrack_standalone.c:1151 ops_exit_list.isra.0+0xfc/0x150 net/core/net_namespace.c:168 cleanup_net+0x4e2/0xa40 net/core/net_namespace.c:575 process_one_work+0x9af/0x1800 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352