INFO: task syz-executor4:7032 blocked for more than 140 seconds. Not tainted 4.19.0-rc2-next-20180903+ #54 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D24952 7032 4666 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x87c/0x1df0 kernel/sched/core.c:3473 schedule+0xfb/0x450 kernel/sched/core.c:3517 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3575 __mutex_lock_common kernel/locking/mutex.c:1003 [inline] __mutex_lock+0xbf9/0x1700 kernel/locking/mutex.c:1073 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088 snd_seq_ioctl+0x221/0x440 sound/core/seq/seq_clientmgr.c:2137 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702 __do_sys_ioctl fs/ioctl.c:709 [inline] __se_sys_ioctl fs/ioctl.c:707 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457099 Code: 48 8b 54 24 38 48 8b 7c 24 48 eb 8d 48 8b 6c 24 50 48 83 c4 58 c3 48 89 04 24 48 89 5c 24 08 e8 0d a9 fb ff 48 8b 44 24 40 48 <8b> 4c 24 48 48 8b 54 24 38 4c 8b 54 24 18 e9 ee fe ff ff 48 89 74 RSP: 002b:00007faff2129c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007faff212a6d4 RCX: 0000000000457099 RDX: 00000000200000c0 RSI: 00000000c08c5332 RDI: 000000000000000b RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d0648 R14: 00000000004bf100 R15: 0000000000000001 INFO: task syz-executor4:7061 blocked for more than 140 seconds. Not tainted 4.19.0-rc2-next-20180903+ #54 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D24536 7061 4666 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x87c/0x1df0 kernel/sched/core.c:3473 schedule+0xfb/0x450 kernel/sched/core.c:3517 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3575 __mutex_lock_common kernel/locking/mutex.c:1003 [inline] __mutex_lock+0xbf9/0x1700 kernel/locking/mutex.c:1073 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088 snd_seq_write+0x1f1/0x8d0 sound/core/seq/seq_clientmgr.c:1021 __vfs_write+0x117/0x9d0 fs/read_write.c:485 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457099 Code: 48 8b 54 24 38 48 8b 7c 24 48 eb 8d 48 8b 6c 24 50 48 83 c4 58 c3 48 89 04 24 48 89 5c 24 08 e8 0d a9 fb ff 48 8b 44 24 40 48 <8b> 4c 24 48 48 8b 54 24 38 4c 8b 54 24 18 e9 ee fe ff ff 48 89 74 RSP: 002b:00007faff20a5c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007faff20a66d4 RCX: 0000000000457099 RDX: 00000000ffffff76 RSI: 0000000020000000 RDI: 000000000000000b RBP: 00000000009303c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d8010 R14: 00000000004cac42 R15: 0000000000000005 Showing all locks held in the system: 2 locks held by kworker/1:0/18: #0: 00000000f1d3efdc ((wq_completion)"rcu_gp"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 00000000f1d3efdc ((wq_completion)"rcu_gp"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000f1d3efdc ((wq_completion)"rcu_gp"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000f1d3efdc ((wq_completion)"rcu_gp"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000f1d3efdc ((wq_completion)"rcu_gp"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000f1d3efdc ((wq_completion)"rcu_gp"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000f1d3efdc ((wq_completion)"rcu_gp"){+.+.}, at: process_one_work+0xb44/0x1aa0 kernel/workqueue.c:2124 #1: 0000000015fea5d9 ((work_completion)(&rew.rew_work)){+.+.}, at: process_one_work+0xb9b/0x1aa0 kernel/workqueue.c:2128 2 locks held by kworker/u4:1/22: #0: 000000007dbdbf82 ((wq_completion)"events_unbound"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 000000007dbdbf82 ((wq_completion)"events_unbound"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000007dbdbf82 ((wq_completion)"events_unbound"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 000000007dbdbf82 ((wq_completion)"events_unbound"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 000000007dbdbf82 ((wq_completion)"events_unbound"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 000000007dbdbf82 ((wq_completion)"events_unbound"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 000000007dbdbf82 ((wq_completion)"events_unbound"){+.+.}, at: process_one_work+0xb44/0x1aa0 kernel/workqueue.c:2124 #1: 00000000fc65b769 ((work_completion)(&sub_info->work)){+.+.}, at: process_one_work+0xb9b/0x1aa0 kernel/workqueue.c:2128 2 locks held by kworker/1:1/24: #0: 000000000d529c86 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 000000000d529c86 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000000d529c86 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 000000000d529c86 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 000000000d529c86 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 000000000d529c86 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 000000000d529c86 ((wq_completion)"events"){+.+.}, at: process_one_work+0xb44/0x1aa0 kernel/workqueue.c:2124 #1: 0000000053eaa5f5 ((work_completion)(&ns->proc_work)){+.+.}, at: process_one_work+0xb9b/0x1aa0 kernel/workqueue.c:2128 4 locks held by kworker/u4:2/28: #0: 00000000995becaa ((wq_completion)"%s""netns"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 00000000995becaa ((wq_completion)"%s""netns"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000995becaa ((wq_completion)"%s""netns"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000995becaa ((wq_completion)"%s""netns"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000995becaa ((wq_completion)"%s""netns"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000995becaa ((wq_completion)"%s""netns"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000995becaa ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0xb44/0x1aa0 kernel/workqueue.c:2124 #1: 00000000b6043629 (net_cleanup_work){+.+.}, at: process_one_work+0xb9b/0x1aa0 kernel/workqueue.c:2128 #2: 0000000027ae2f5c (pernet_ops_rwsem){++++}, at: cleanup_net+0x13f/0xb60 net/core/net_namespace.c:518 #3: 000000005f1ae6c2 (rcu_sched_state.barrier_mutex){+.+.}, at: _rcu_barrier+0x14a/0x790 kernel/rcu/tree.c:3413 2 locks held by kworker/u4:3/83: #0: 000000007dbdbf82 ((wq_completion)"events_unbound"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 000000007dbdbf82 ((wq_completion)"events_unbound"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000007dbdbf82 ((wq_completion)"events_unbound"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 000000007dbdbf82 ((wq_completion)"events_unbound"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 000000007dbdbf82 ((wq_completion)"events_unbound"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 000000007dbdbf82 ((wq_completion)"events_unbound"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 000000007dbdbf82 ((wq_completion)"events_unbound"){+.+.}, at: process_one_work+0xb44/0x1aa0 kernel/workqueue.c:2124 #1: 000000006d856844 ((work_completion)(&sub_info->work)){+.+.}, at: process_one_work+0xb9b/0x1aa0 kernel/workqueue.c:2128 1 lock held by khungtaskd/792: #0: 000000003aebf143 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4436 1 lock held by rsyslogd/4526: 2 locks held by getty/4616: #0: 00000000bc77f192 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000bdc6dde6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4617: #0: 000000005aaad2f9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000b9cf7878 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4618: #0: 00000000e11faba3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000958866c5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4619: #0: 00000000c3774e96 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000148b14fc (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4620: #0: 000000008a8beda4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000fc18e26b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4621: #0: 00000000c803b699 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000009b9072c9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4622: #0: 0000000000cdd384 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000006608794f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 3 locks held by syz-executor7/4668: 2 locks held by syz-executor4/7003: 1 lock held by syz-executor4/7032: #0: 000000000cd6d267 (&client->ioctl_mutex){+.+.}, at: snd_seq_ioctl+0x221/0x440 sound/core/seq/seq_clientmgr.c:2137 1 lock held by syz-executor4/7061: #0: 000000000cd6d267 (&client->ioctl_mutex){+.+.}, at: snd_seq_write+0x1f1/0x8d0 sound/core/seq/seq_clientmgr.c:1021 2 locks held by syz-executor1/7059: #0: 000000008ad34815 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 #1: 0000000095648ebc (rcu_sched_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #1: 0000000095648ebc (rcu_sched_state.exp_mutex){+.+.}, at: _synchronize_rcu_expedited.constprop.72+0x80d/0xa40 kernel/rcu/tree_exp.h:667 2 locks held by kworker/1:4/7088: #0: 000000000d529c86 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 000000000d529c86 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000000d529c86 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 000000000d529c86 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 000000000d529c86 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 000000000d529c86 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 000000000d529c86 ((wq_completion)"events"){+.+.}, at: process_one_work+0xb44/0x1aa0 kernel/workqueue.c:2124 #1: 000000007d3f36f1 ((work_completion)(&ns->proc_work)){+.+.}, at: process_one_work+0xb9b/0x1aa0 kernel/workqueue.c:2128 1 lock held by /7089: #0: 000000004a8f41c1 (event_mutex){+.+.}, at: perf_trace_destroy+0x28/0x100 kernel/trace/trace_event_perf.c:236 1 lock held by modprobe/7106: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 792 Comm: khungtaskd Not tainted 4.19.0-rc2-next-20180903+ #54 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+0x1c9/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.3+0x48/0x88 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x151/0x192 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:204 [inline] watchdog+0xb39/0x1040 kernel/hung_task.c:265 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7003 Comm: syz-executor4 Not tainted 4.19.0-rc2-next-20180903+ #54 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:separate_irq_context kernel/locking/lockdep.c:3041 [inline] RIP: 0010:__lock_acquire+0x8d2/0x5020 kernel/locking/lockdep.c:3403 Code: d1 30 00 00 48 8b 4c 24 78 49 89 12 48 b8 00 00 00 00 00 fc ff df 48 c1 e9 03 0f b6 04 01 84 c0 74 08 3c 03 0f 8e 88 30 00 00 <41> 8b 86 38 08 00 00 85 c0 74 7a 48 8b b4 24 88 00 00 00 48 8d 04 RSP: 0018:ffff880186a47400 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000653 RCX: 1ffff1003b27addf RDX: 1b7c5908ed9e89c7 RSI: 0000000000000000 RDI: ffffffff896fd250 RBP: ffff880186a47788 R08: 0000000000000008 R09: 0000000000000001 R10: ffff8801d93d6f28 R11: ffff8801d93d6eec R12: 0000000000000653 R13: 0000000000000006 R14: ffff8801d93d66c0 R15: 0000000000000000 FS: 00007faff214b700(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020e00000 CR3: 00000001b9b68000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1e4/0x4f0 kernel/locking/lockdep.c:3901 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152 snd_seq_prioq_cell_in+0x7d/0x7a0 sound/core/seq/seq_prioq.c:160 snd_seq_enqueue_event+0x317/0x4d0 sound/core/seq/seq_queue.c:328 snd_seq_client_enqueue_event+0x2a5/0x510 sound/core/seq/seq_clientmgr.c:957 snd_seq_write+0x3f1/0x8d0 sound/core/seq/seq_clientmgr.c:1074 __vfs_write+0x117/0x9d0 fs/read_write.c:485 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457099 Code: fd b4 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 b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007faff214ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007faff214b6d4 RCX: 0000000000457099 RDX: 00000000ffffff76 RSI: 0000000020000000 RDI: 0000000000000005 RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d8010 R14: 00000000004cac42 R15: 0000000000000000