INFO: task syz-executor.0:19482 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.0 D28120 19482 7022 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: ffffffff8a5772f0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa50 net/core/net_namespace.c:565 1 lock held by khungtaskd/1140: #0: ffffffff899bea80 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5754 2 locks held by syz-executor.0/19482: #0: ffff888087a21210 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:797 [inline] #0: ffff888087a21210 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: __sock_release+0x86/0x280 net/socket.c:604 #1: ffffffff8a5772f0 (pernet_ops_rwsem){++++}-{3:3}, at: unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1776 1 lock held by syz-executor.0/19631: #0: ffffffff8a5772f0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x270/0x590 net/core/net_namespace.c:478 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1140 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 19182 Comm: kworker/1:37 Not tainted 5.7.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_power_efficient gc_worker RIP: 0010:validate_chain kernel/locking/lockdep.c:3244 [inline] RIP: 0010:__lock_acquire+0xd6f/0x4c50 kernel/locking/lockdep.c:4355 Code: fc ff df 48 c1 ea 03 0f b6 14 02 48 c7 c0 94 8b 89 8a 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 77 33 00 00 8b 3d 45 59 30 09 <85> ff 0f 84 16 0c 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 54 24 RSP: 0018:ffffc900162379d8 EFLAGS: 00000046 RAX: 0000000000000007 RBX: 0000000000000c3c RCX: a94fbe8be980cd02 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000001 RBP: ffff888048db8c40 R08: 0000000000000001 R09: fffffbfff185d13b R10: ffffffff8c2e89d7 R11: fffffbfff185d13a R12: ffff888048db8300 R13: dffffc0000000000 R14: 0000000000000000 R15: ffffffff8a898b90 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6bf49c0000 CR3: 000000009628e000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mark_held_locks+0xe0/0xe0 kernel/locking/lockdep.c:3620 mark_held_locks+0xe0/0xe0 kernel/locking/lockdep.c:3620 test_bit include/asm-generic/bitops/instrumented-non-atomic.h:110 [inline] hlock_class kernel/locking/lockdep.c:179 [inline] lookup_chain_cache_add kernel/locking/lockdep.c:3146 [inline] validate_chain kernel/locking/lockdep.c:3202 [inline] __lock_acquire+0x2184/0x4c50 kernel/locking/lockdep.c:4355 lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934 process_one_work+0x965/0x16a0 kernel/workqueue.c:2268 lock_release+0x800/0x800 kernel/locking/lockdep.c:4689 seqcount_lockdep_reader_access include/linux/seqlock.h:81 [inline] read_seqcount_begin include/linux/seqlock.h:164 [inline] nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:300 [inline] gc_worker+0x24f/0xd40 net/netfilter/nf_conntrack_core.c:1385 process_one_work+0x965/0x16a0 kernel/workqueue.c:2268 init_conntrack.isra.0+0x1080/0x1080 net/netfilter/nf_conntrack_core.c:1627 lock_is_held include/linux/lockdep.h:406 [inline] rcu_read_lock_sched_held+0x9c/0xd0 kernel/rcu/update.c:121 rcu_read_lock_any_held.part.0+0x50/0x50 arch/x86/include/asm/paravirt.h:754 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:199 process_one_work+0x965/0x16a0 kernel/workqueue.c:2268 lock_release+0x800/0x800 kernel/locking/lockdep.c:4689 pwq_dec_nr_in_flight+0x310/0x310 kernel/workqueue.c:1198 rwlock_bug.part.0+0x90/0x90 include/linux/sched.h:1329 worker_thread+0x96/0xe20 kernel/workqueue.c:2414 process_one_work+0x16a0/0x16a0 kernel/workqueue.c:2273 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