INFO: task syz-executor0:8000 blocked for more than 140 seconds. Not tainted 4.20.0-rc1-next-20181109+ #110 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D19160 8000 6045 0x80000006 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472 schedule+0xef/0x370 kernel/sched/core.c:3516 __rwsem_down_write_failed_common+0xc9a/0x15e0 kernel/locking/rwsem-xadd.c:577 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:606 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0xa5/0x130 kernel/locking/rwsem.c:72 deactivate_super+0x2b3/0x320 fs/super.c:358 cleanup_mnt+0xbf/0x160 fs/namespace.c:1049 __cleanup_mnt+0x16/0x20 fs/namespace.c:1056 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x1a48/0x2620 kernel/exit.c:867 kworker/u4:3(54): getblk(): executed=9 bh_count=0 bh_state=0 do_group_exit+0x177/0x440 kernel/exit.c:970 get_signal+0x8a8/0x1970 kernel/signal.c:2517 do_signal+0x9c/0x21c0 arch/x86/kernel/signal.c:816 exit_to_usermode_loop+0x2e5/0x380 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f9cb9f48cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000072bf08 RCX: 0000000000457569 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000072bf08 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000072bf0c R13: 00007ffee4172e3f R14: 00007f9cb9f499c0 R15: 0000000000000000 Showing all locks held in the system: 3 locks held by kworker/u4:3/54: 1 lock held by khungtaskd/1010: #0: 00000000455f2467 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 2 locks held by kworker/u4:4/2528: #0: 000000009b017a5f ((wq_completion)"events_unbound"){+.+.}, at: __write_once_size include/linux/compiler.h:209 [inline] #0: 000000009b017a5f ((wq_completion)"events_unbound"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000009b017a5f ((wq_completion)"events_unbound"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 000000009b017a5f ((wq_completion)"events_unbound"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 000000009b017a5f ((wq_completion)"events_unbound"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 000000009b017a5f ((wq_completion)"events_unbound"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 000000009b017a5f ((wq_completion)"events_unbound"){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124 #1: 00000000ae211c3e (connector_reaper_work){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128 1 lock held by rsyslogd/5918: #0: 00000000f7edf495 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/6008: #0: 00000000b1797b86 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000eb803cce (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6009: #0: 00000000039d70f3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000e9601c38 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6010: #0: 00000000e9e63aac (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000878e6432 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6011: #0: 00000000af9e20f7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000009c8b5c42 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6012: #0: 0000000005272184 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000064afd594 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6013: #0: 00000000d5e09163 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000027984e61 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6014: #0: 000000004fc9ec02 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000019dbd330 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by kworker/1:3/6240: 1 lock held by syz-executor0/8000: #0: 0000000066710194 (&fc->fs_type->s_umount_key#70){++++}, at: deactivate_super+0x2b3/0x320 fs/super.c:358 3 locks held by kworker/0:4/16112: #0: 0000000072e2d4a1 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:209 [inline] #0: 0000000072e2d4a1 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000072e2d4a1 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 0000000072e2d4a1 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 0000000072e2d4a1 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 0000000072e2d4a1 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 0000000072e2d4a1 ((wq_completion)"events"){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124 #1: 0000000025a1e6c3 ((linkwatch_work).work){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128 #2: 0000000068bdad60 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 2 locks held by kworker/u4:7/16271: #0: 000000009b017a5f ((wq_completion)"events_unbound"){+.+.}, at: __write_once_size include/linux/compiler.h:209 [inline] #0: 000000009b017a5f ((wq_completion)"events_unbound"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000009b017a5f ((wq_completion)"events_unbound"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 000000009b017a5f ((wq_completion)"events_unbound"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 000000009b017a5f ((wq_completion)"events_unbound"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 000000009b017a5f ((wq_completion)"events_unbound"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 000000009b017a5f ((wq_completion)"events_unbound"){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124 #1: 000000002db622fb ((reaper_work).work){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128 1 lock held by syz-executor0/22817: 1 lock held by syz-executor0/22879: 1 lock held by syz-executor0/22935: 2 locks held by syz-executor5/23234: #0: 0000000068bdad60 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 #1: 000000008c90f7bb (rcu_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:296 [inline] #1: 000000008c90f7bb (rcu_state.exp_mutex){+.+.}, at: _synchronize_rcu_expedited.constprop.60+0x7c7/0x9d0 kernel/rcu/tree_exp.h:622 1 lock held by syz-executor4/23238: #0: 0000000068bdad60 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 1 lock held by syz-executor2/23247: #0: 0000000068bdad60 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1010 Comm: khungtaskd Not tainted 4.20.0-rc1-next-20181109+ #110 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+0x244/0x39d lib/dump_stack.c:113 nmi_cpu_backtrace.cold.2+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1e8/0x22a 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:144 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xb4c/0x1060 kernel/hung_task.c:289 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.591 msecs NMI backtrace for cpu 1 CPU: 1 PID: 6240 Comm: kworker/1:3 Not tainted 4.20.0-rc1-next-20181109+ #110 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events iterate_cleanup_work RIP: 0010:hlock_class kernel/locking/lockdep.c:152 [inline] RIP: 0010:mark_lock+0xdf/0x1cd0 kernel/locking/lockdep.c:3033 Code: 8e 89 06 00 00 41 0f b7 44 24 20 66 a9 ff 1f 0f 84 b8 00 00 00 48 ba 00 00 00 00 00 fc ff df 4c 89 c1 48 c1 e9 03 0f b6 14 11 <84> d2 74 09 80 fa 03 0f 8e 8e 06 00 00 25 ff 1f 00 00 4c 8d 2c 80 RSP: 0018:ffff880190d4eea8 EFLAGS: 00000806 RAX: 0000000000000339 RBX: 1ffff100321a9ddb RCX: 1ffff100321a8d7e RDX: 0000000000000000 RSI: ffff880190d46bd0 RDI: ffff880190d46300 RBP: ffff880190d4efe0 R08: ffff880190d46bf0 R09: 0000000000000008 R10: 0000000000000050 R11: ffff880190d46300 R12: ffff880190d46bd0 R13: ffff880190d46b6c R14: 0000000000000100 R15: ffff880190d4efb8 FS: 0000000000000000(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000023d7978 CR3: 00000001d3105000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_acquire+0x62f/0x4c20 kernel/locking/lockdep.c:3302 lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] nf_conntrack_lock+0x75/0x170 net/netfilter/nf_conntrack_core.c:95 get_next_corpse net/netfilter/nf_conntrack_core.c:1881 [inline] nf_ct_iterate_cleanup+0x255/0x5e0 net/netfilter/nf_conntrack_core.c:1915 nf_ct_iterate_cleanup_net+0x237/0x2d0 net/netfilter/nf_conntrack_core.c:2000 iterate_cleanup_work+0x48/0xe0 net/ipv6/netfilter/nf_nat_masquerade_ipv6.c:113 process_one_work+0xc8b/0x1c40 kernel/workqueue.c:2153 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352