INFO: task syz-executor.5:30440 blocked for more than 143 seconds. Not tainted 5.7.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D27448 30440 7503 0x80004006 Call Trace: context_switch kernel/sched/core.c:3367 [inline] __schedule+0x937/0x1ff0 kernel/sched/core.c:4083 rwsem_down_write_slowpath+0x90a/0xf90 kernel/locking/rwsem.c:1216 __sched_text_start+0x8/0x8 schedule+0xd0/0x2a0 kernel/sched/core.c:4158 rwsem_down_write_slowpath+0x706/0xf90 kernel/locking/rwsem.c:1235 rwsem_mark_wake+0x8d0/0x8d0 include/linux/compiler.h:199 lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934 unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1776 lock_release+0x800/0x800 kernel/locking/lockdep.c:4689 __sock_release+0x280/0x280 net/socket.c:605 __down_write kernel/locking/rwsem.c:1389 [inline] down_write+0x137/0x150 kernel/locking/rwsem.c:1532 atomic64_try_cmpxchg include/asm-generic/atomic-instrumented.h:1504 [inline] atomic_long_try_cmpxchg_acquire include/asm-generic/atomic-long.h:442 [inline] __down_write kernel/locking/rwsem.c:1387 [inline] down_write+0xb2/0x150 kernel/locking/rwsem.c:1532 __down_write kernel/locking/rwsem.c:1389 [inline] down_write+0x137/0x150 kernel/locking/rwsem.c:1532 __down_timeout+0x2d0/0x2d0 unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1776 __sock_release+0x280/0x280 net/socket.c:605 raw_release+0x53/0x730 net/can/raw.c:354 fcntl_setlk+0xcc0/0xcc0 fs/locks.c:2542 __sock_release+0x280/0x280 net/socket.c:605 __sock_release+0xcd/0x280 net/socket.c:605 sock_close+0x18/0x20 net/socket.c:1283 __fput+0x33e/0x880 fs/file_table.c:280 task_work_run+0xf4/0x1b0 kernel/task_work.c:123 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xb34/0x2dd0 kernel/exit.c:796 find_held_lock+0x2d/0x110 kernel/locking/lockdep.c:4458 mm_update_next_owner+0x7a0/0x7a0 kernel/exit.c:375 lock_downgrade+0x840/0x840 kernel/locking/lockdep.c:4579 do_group_exit+0x125/0x340 kernel/exit.c:894 get_signal+0x47b/0x24e0 kernel/signal.c:2739 find_held_lock+0x2d/0x110 kernel/locking/lockdep.c:4458 do_signal+0x81/0x2240 arch/x86/kernel/signal.c:784 lock_downgrade+0x840/0x840 kernel/locking/lockdep.c:4579 rcu_read_lock_any_held.part.0+0x50/0x50 arch/x86/include/asm/paravirt.h:754 get_sigframe.isra.0+0x730/0x730 arch/x86/kernel/signal.c:268 rcu_read_unlock_sched include/linux/rcupdate.h:732 [inline] __fd_install+0x1e6/0x600 fs/file.c:613 __sys_socket+0x16d/0x200 net/socket.c:438 move_addr_to_kernel+0x70/0x70 net/socket.c:195 exit_to_usermode_loop+0x26c/0x360 arch/x86/entry/common.c:161 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x6b1/0x7d0 arch/x86/entry/common.c:305 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Showing all locks held in the system: 3 locks held by kworker/u4:0/7: #0: ffff8880a9771938 ((wq_completion)netns){+.+.}-{0:0}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8880a9771938 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880a9771938 ((wq_completion)netns){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8880a9771938 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8880a9771938 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8880a9771938 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8880a9771938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 kernel/workqueue.c:2239 #1: ffffc90000cdfdc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 kernel/workqueue.c:2243 #2: ffffffff8a57a930 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa50 net/core/net_namespace.c:565 1 lock held by khungtaskd/1144: #0: ffffffff899bea80 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5754 1 lock held by in:imklog/6719: #0: ffff88809f29e630 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 2 locks held by syz-executor.5/30440: #0: ffff88804bdec750 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:797 [inline] #0: ffff88804bdec750 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: __sock_release+0x86/0x280 net/socket.c:604 #1: ffffffff8a57a930 (pernet_ops_rwsem){++++}-{3:3}, at: unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1776 1 lock held by syz-executor.5/30792: #0: ffffffff8a57a930 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x270/0x590 net/core/net_namespace.c:478 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1144 Comm: khungtaskd Not tainted 5.7.0-rc5-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+0x188/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 lapic_can_unplug_cpu.cold+0x3b/0x3b nmi_trigger_cpumask_backtrace+0x231/0x27e lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xa8c/0x1010 kernel/hung_task.c:289 reset_hung_task_detector+0x30/0x30 kernel/hung_task.c:243 kthread+0x388/0x470 kernel/kthread.c:268 kthread_mod_delayed_work+0x1a0/0x1a0 kernel/kthread.c:1090 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4111 Comm: systemd-journal Not tainted 5.7.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:pick_next_task_fair+0x5c/0xc70 kernel/sched/fair.c:6940 Code: 89 f0 48 89 74 24 20 83 e6 07 48 c1 e8 03 49 89 f6 48 89 3c 24 48 01 d8 41 83 c6 03 48 89 44 24 08 49 8d 45 78 48 89 44 24 18 <48> 8b 44 24 08 0f b6 00 41 38 c6 7c 08 84 c0 0f 85 5b 0a 00 00 48 RSP: 0018:ffffc90004a77ad0 EFLAGS: 00000006 RAX: ffff888093648338 RBX: dffffc0000000000 RCX: 1ffff110126c909e RDX: ffffc90004a77b90 RSI: 0000000000000000 RDI: ffff8880ae637980 RBP: ffffc90004a77bf8 R08: 0000000000200000 R09: 1ffff110126c9091 R10: ffff888093648498 R11: ffffed1015cc7103 R12: ffffc90004a77b90 R13: ffff8880936482c0 R14: 0000000000000003 R15: ffff8880ae637998 FS: 00007fbe21b848c0(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbe1f069000 CR3: 0000000093b23000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: pick_next_task kernel/sched/core.c:3921 [inline] __schedule+0x375/0x1ff0 kernel/sched/core.c:4051 __sched_text_start+0x8/0x8 lock_downgrade+0x840/0x840 kernel/locking/lockdep.c:4579 schedule+0xd0/0x2a0 kernel/sched/core.c:4158 schedule_hrtimeout_range_clock+0x2ef/0x340 kernel/time/hrtimer.c:2128 hrtimer_nanosleep_restart+0x140/0x140 kernel/time/hrtimer.c:1916 ep_scan_ready_list+0x602/0x960 fs/eventpoll.c:756 lock_downgrade+0x840/0x840 kernel/locking/lockdep.c:4579 atomic_try_cmpxchg include/asm-generic/atomic-instrumented.h:694 [inline] queued_write_lock include/asm-generic/qrwlock.h:92 [inline] do_raw_write_lock+0x11a/0x280 kernel/locking/spinlock_debug.c:207 do_raw_read_unlock+0x70/0x70 kernel/locking/spinlock_debug.c:176 __raw_write_unlock_irq include/linux/rwlock_api_smp.h:267 [inline] _raw_write_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:343 ep_poll+0xcef/0xf00 fs/eventpoll.c:1910 ep_send_events_proc+0xc30/0xc30 include/linux/list.h:72 debug_object_deactivate+0x320/0x320 lib/debugobjects.c:714 __secure_computing+0x104/0x360 kernel/seccomp.c:950 finish_wait+0x260/0x260 include/linux/list.h:301 syscall_slow_exit_work+0x630/0x630 include/linux/tracehook.h:75 do_epoll_wait+0x209/0x260 fs/eventpoll.c:2333 trace_hardirqs_off_caller+0x55/0x230 kernel/trace/trace_preemptirq.c:73 __do_sys_epoll_wait fs/eventpoll.c:2343 [inline] __se_sys_epoll_wait fs/eventpoll.c:2340 [inline] __x64_sys_epoll_wait+0x93/0xf0 fs/eventpoll.c:2340 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x7fbe20e4e2e3 Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 83 3d 29 54 2b 00 00 75 13 49 89 ca b8 e8 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 0b c2 00 00 48 89 04 24 RSP: 002b:00007ffc45ab3588 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8 RAX: ffffffffffffffda RBX: 000055ae4270a1e0 RCX: 00007fbe20e4e2e3 RDX: 0000000000000013 RSI: 00007ffc45ab3590 RDI: 0000000000000008 RBP: 00007ffc45ab3780 R08: 00007ffc45b31080 R09: 000000005ec69602 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc45ab3590 R13: 0000000000000001 R14: ffffffffffffffff R15: 0005a629ae753659