INFO: task syz-executor.5:21668 blocked for more than 143 seconds. Not tainted 5.3.0-rc3+ #137 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28160 21668 8239 0x00000004 Call Trace: context_switch kernel/sched/core.c:3254 [inline] __schedule+0x755/0x1580 kernel/sched/core.c:3880 schedule+0xa8/0x270 kernel/sched/core.c:3944 rwsem_down_write_slowpath+0x708/0xf60 kernel/locking/rwsem.c:1214 __down_write kernel/locking/rwsem.c:1365 [inline] down_write+0x13c/0x150 kernel/locking/rwsem.c:1501 unregister_netdevice_notifier+0x7e/0x390 net/core/dev.c:1713 bcm_release+0x93/0x5e0 net/can/bcm.c:1474 __sock_release+0xce/0x280 net/socket.c:590 sock_close+0x1e/0x30 net/socket.c:1268 __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+0x316/0x380 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] syscall_return_slowpath arch/x86/entry/common.c:274 [inline] do_syscall_64+0x5a9/0x6a0 arch/x86/entry/common.c:299 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x413511 Code: 8c d6 65 00 ba 02 00 00 00 bf 28 38 44 00 ff 15 7d a1 24 00 85 c0 0f 85 37 fe ff ff 31 c9 31 f6 41 b9 b0 20 41 00 41 b8 90 d6 <65> 00 ba 03 00 00 00 bf 31 38 44 00 ff 15 55 a1 24 00 85 c0 0f 85 RSP: 002b:00007ffdd29db090 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000413511 RDX: 0000001b2e920000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00000000f810385f R09: 00000000f8103863 R10: 00007ffdd29db170 R11: 0000000000000293 R12: 000000000075c9a0 R13: 000000000075c9a0 R14: 0000000000767ee0 R15: ffffffffffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1056: #0: 00000000793bd7ed (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5256 4 locks held by kworker/u4:4/3078: 1 lock held by rsyslogd/8094: #0: 00000000945e2bf8 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/8184: #0: 00000000ea79c653 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: 00000000897c58c1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8185: #0: 000000007d0bd323 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: 0000000075bfdcde (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8186: #0: 00000000a7bd0b8a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: 00000000d14ace30 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8187: #0: 00000000515755d1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: 0000000037857065 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8188: #0: 000000001c26862f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: 000000002ce1b8e3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8189: #0: 0000000033946063 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: 000000004b0d9b33 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8190: #0: 00000000ba019455 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: 00000000d372fa3f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.5/21668: #0: 000000003264aed0 (&sb->s_type->i_mutex_key#12){+.+.}, at: inode_lock include/linux/fs.h:778 [inline] #0: 000000003264aed0 (&sb->s_type->i_mutex_key#12){+.+.}, at: __sock_release+0x89/0x280 net/socket.c:589 #1: 00000000094f7769 (pernet_ops_rwsem){++++}, at: unregister_netdevice_notifier+0x7e/0x390 net/core/dev.c:1713 1 lock held by syz-executor.0/21702: #0: 00000000094f7769 (pernet_ops_rwsem){++++}, at: copy_net_ns+0x26d/0x41f net/core/net_namespace.c:471 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1056 Comm: khungtaskd Not tainted 5.3.0-rc3+ #137 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+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+0x9d0/0xef0 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: NMI backtrace for cpu 0 CPU: 0 PID: 3078 Comm: kworker/u4:4 Not tainted 5.3.0-rc3+ #137 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net RIP: 0010:__trace_hardirqs_on_caller kernel/locking/lockdep.c:3317 [inline] RIP: 0010:lockdep_hardirqs_on+0x1f4/0x5d0 kernel/locking/lockdep.c:3359 Code: 42 03 00 00 8b 83 78 08 00 00 85 c0 0f 85 2f 02 00 00 48 8d bb 40 08 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 87 03 00 00 48 8d bb 38 08 00 00 4c 89 a3 40 08 RSP: 0018:ffff88809f68faa8 EFLAGS: 00000806 RAX: dffffc0000000000 RBX: ffff88809f682140 RCX: 0000000000000007 RDX: 1ffff11013ed0530 RSI: 0000000000000008 RDI: ffff88809f682980 RBP: ffff88809f68fab8 R08: 1ffffffff14a9141 R09: fffffbfff14a9142 R10: fffffbfff14a9141 R11: ffffffff8a548a0f R12: ffffffff8145990a R13: ffffffff85d2e077 R14: ffffffff8145990a R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c420210dec CR3: 0000000093c4c000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_hardirqs_on+0x67/0x240 kernel/trace/trace_preemptirq.c:31 __local_bh_enable_ip+0x15a/0x270 kernel/softirq.c:194 local_bh_enable include/linux/bottom_half.h:32 [inline] get_next_corpse net/netfilter/nf_conntrack_core.c:2014 [inline] nf_ct_iterate_cleanup+0x217/0x4e0 net/netfilter/nf_conntrack_core.c:2037 nf_conntrack_cleanup_net_list+0x7a/0x240 net/netfilter/nf_conntrack_core.c:2224 nf_conntrack_pernet_exit+0x159/0x1a0 net/netfilter/nf_conntrack_standalone.c:1149 ops_exit_list.isra.0+0xfc/0x150 net/core/net_namespace.c:175 cleanup_net+0x4e2/0xa70 net/core/net_namespace.c:594 process_one_work+0x9af/0x1740 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