INFO: task syz-executor.5:16491 blocked for more than 143 seconds. Not tainted 5.10.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.5 state:D stack:27608 pid:16491 ppid: 8530 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:3774 [inline] __schedule+0x893/0x2130 kernel/sched/core.c:4523 schedule+0xcf/0x270 kernel/sched/core.c:4601 rwsem_down_write_slowpath+0x603/0xc60 kernel/locking/rwsem.c:1235 __down_write kernel/locking/rwsem.c:1389 [inline] down_write+0x137/0x150 kernel/locking/rwsem.c:1532 unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1863 raw_release+0x58/0x890 net/can/raw.c:352 __sock_release+0xcd/0x280 net/socket.c:596 sock_close+0x18/0x20 net/socket.c:1277 __fput+0x285/0x920 fs/file_table.c:281 task_work_run+0xdd/0x190 kernel/task_work.c:151 exit_task_work include/linux/task_work.h:30 [inline] do_exit+0xb64/0x29b0 kernel/exit.c:809 do_group_exit+0x125/0x310 kernel/exit.c:906 get_signal+0x428/0x1f00 kernel/signal.c:2758 arch_do_signal+0x82/0x2390 arch/x86/kernel/signal.c:811 exit_to_user_mode_loop kernel/entry/common.c:161 [inline] exit_to_user_mode_prepare+0x100/0x1a0 kernel/entry/common.c:191 syscall_exit_to_user_mode+0x38/0x260 kernel/entry/common.c:266 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45deb9 Code: Unable to access opcode bytes at RIP 0x45de8f. RSP: 002b:00007f4fe275bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: 0000000000000004 RBX: 0000000000034380 RCX: 000000000045deb9 RDX: 0000000000000001 RSI: 0000000000000003 RDI: 000000000000001d RBP: 000000000118c0b0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118c07c R13: 00007ffcc62b728f R14: 00007f4fe275c9c0 R15: 000000000118c07c Showing all locks held in the system: 1 lock held by khungtaskd/1657: #0: ffffffff8b337160 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6253 1 lock held by in:imklog/8176: #0: ffff88801c6dc5f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:932 3 locks held by kworker/u4:9/20576: 2 locks held by syz-executor.5/16491: #0: ffff888183cc11d0 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:774 [inline] #0: ffff888183cc11d0 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: __sock_release+0x86/0x280 net/socket.c:595 #1: ffffffff8c913b50 (pernet_ops_rwsem){++++}-{3:3}, at: unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1863 2 locks held by kworker/u4:2/16993: #0: ffff8880b9e34d18 (&rq->lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1292 [inline] #0: ffff8880b9e34d18 (&rq->lock){-.-.}-{2:2}, at: __schedule+0x21a/0x2130 kernel/sched/core.c:4441 #1: ffffc9001cd67da8 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work+0x854/0x15a0 kernel/workqueue.c:2247 1 lock held by syz-executor.5/17049: #0: ffffffff8c913b50 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x2ac/0x5e0 net/core/net_namespace.c:479 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1657 Comm: khungtaskd Not tainted 5.10.0-rc3-syzkaller #0 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+0x107/0x163 lib/dump_stack.c:118 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+0x3af/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 20576 Comm: kworker/u4:9 Not tainted 5.10.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net RIP: 0010:lockdep_hardirqs_on_prepare kernel/locking/lockdep.c:4084 [inline] RIP: 0010:lockdep_hardirqs_on_prepare+0x1cc/0x400 kernel/locking/lockdep.c:4049 Code: 00 00 00 00 fc ff df 48 89 da 83 e3 07 48 c1 ea 03 83 c3 03 0f b6 04 02 38 c3 7c 08 84 c0 0f 85 06 01 00 00 8b 35 14 db 9d 0d <85> f6 0f 85 dd fe ff ff 48 c7 c0 c8 53 ec 8c 48 ba 00 00 00 00 00 RSP: 0018:ffffc90009a9fb48 EFLAGS: 00000097 RAX: 0000000000000004 RBX: 0000000000000003 RCX: 1ffffffff19d97eb RDX: 1ffffffff1de7524 RSI: 0000000000000000 RDI: ffffffff8142683c RBP: ffffffff8142683c R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff8b06dc80 R13: 0000000000002248 R14: 0000000000000000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb4ff108ab4 CR3: 00000000137b3000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_hardirqs_on+0x5b/0x1c0 kernel/trace/trace_preemptirq.c:49 __local_bh_enable_ip+0x9c/0x110 kernel/softirq.c:200 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/0xa00 net/core/net_namespace.c:604 process_one_work+0x933/0x15a0 kernel/workqueue.c:2272 worker_thread+0x64c/0x1120 kernel/workqueue.c:2418 kthread+0x3af/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296