INFO: task syz-executor.5:15124 blocked for more than 143 seconds. Not tainted 5.10.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.5 state:D stack:26064 pid:15124 ppid: 8543 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5078 schedule+0xcf/0x270 kernel/sched/core.c:5157 rwsem_down_write_slowpath+0x7e5/0x1200 kernel/locking/rwsem.c:1106 __down_write_common kernel/locking/rwsem.c:1261 [inline] __down_write_common kernel/locking/rwsem.c:1258 [inline] __down_write kernel/locking/rwsem.c:1270 [inline] down_write+0x132/0x150 kernel/locking/rwsem.c:1407 unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1868 raw_release+0x58/0x890 net/can/raw.c:352 __sock_release+0xcd/0x280 net/socket.c:597 sock_close+0x18/0x20 net/socket.c:1256 __fput+0x283/0x920 fs/file_table.c:280 task_work_run+0xdd/0x190 kernel/task_work.c:140 exit_task_work include/linux/task_work.h:30 [inline] do_exit+0xb89/0x29e0 kernel/exit.c:823 do_group_exit+0x125/0x310 kernel/exit.c:920 get_signal+0x3ec/0x2010 kernel/signal.c:2770 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811 handle_signal_work kernel/entry/common.c:147 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e219 RSP: 002b:00007fe4cb947c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: 0000000000000003 RBX: 0000000000000003 RCX: 000000000045e219 RDX: 0000000000000001 RSI: 0000000000000003 RDI: 000000000000001d RBP: 000000000119bfc0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c R13: 00007ffc350a6cef R14: 00007fe4cb9489c0 R15: 000000000119bf8c Showing all locks held in the system: 3 locks held by kworker/u4:1/22: 3 locks held by kworker/u4:6/250: 1 lock held by khungtaskd/1656: #0: ffffffff8b35efa0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6254 1 lock held by systemd-journal/4890: 1 lock held by in:imklog/8180: #0: ffff888020675770 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:947 2 locks held by syz-executor.5/15124: #0: ffff8881a79e2190 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:773 [inline] #0: ffff8881a79e2190 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: __sock_release+0x86/0x280 net/socket.c:596 #1: ffffffff8c928c10 (pernet_ops_rwsem){++++}-{3:3}, at: unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1868 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1656 Comm: khungtaskd Not tainted 5.10.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline] watchdog+0xd43/0xfa0 kernel/hung_task.c:294 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 250 Comm: kworker/u4:6 Not tainted 5.10.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net RIP: 0010:mark_held_locks+0x41/0xe0 kernel/locking/lockdep.c:4000 Code: 09 00 00 48 89 fa 55 89 f5 53 48 c1 ea 03 48 83 ec 08 0f b6 04 02 84 c0 74 08 3c 03 0f 8e 89 00 00 00 41 8b 84 24 80 09 00 00 <31> db 49 bd 00 00 00 00 00 fc ff df 4d 8d b4 24 88 09 00 00 85 c0 RSP: 0018:ffffc9000164fb10 EFLAGS: 00000046 RAX: 0000000000000003 RBX: ffff888011c08000 RCX: ffffffff8156f5e7 RDX: 1ffff11002381130 RSI: 0000000000000006 RDI: ffff888011c08980 RBP: 0000000000000006 R08: 0000000000000000 R09: ffffffff8ebc97af R10: fffffbfff1d792f5 R11: 0000000000000000 R12: ffff888011c08000 R13: 00000000000023ac R14: 0000000000000000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f17765c0000 CR3: 0000000025898000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __trace_hardirqs_on_caller kernel/locking/lockdep.c:4038 [inline] lockdep_hardirqs_on_prepare kernel/locking/lockdep.c:4098 [inline] lockdep_hardirqs_on_prepare+0x28b/0x400 kernel/locking/lockdep.c:4050 trace_hardirqs_on+0x5b/0x1c0 kernel/trace/trace_preemptirq.c:49 __local_bh_enable_ip+0x9c/0x110 kernel/softirq.c:201 local_bh_enable include/linux/bottom_half.h:32 [inline] get_next_corpse net/netfilter/nf_conntrack_core.c:2221 [inline] nf_ct_iterate_cleanup+0x11f/0x400 net/netfilter/nf_conntrack_core.c:2244 nf_conntrack_cleanup_net_list+0x81/0x250 net/netfilter/nf_conntrack_core.c:2431 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:190 cleanup_net+0x4ea/0xb10 net/core/net_namespace.c:604 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296