INFO: task syz-executor5:10209 blocked for more than 140 seconds. Not tainted 4.19.0-rc1+ #214 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D25408 10209 4688 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: 0033:0x457089 Code: 08 e8 3b a9 fb ff 48 8b 44 24 20 48 8b 4c 24 18 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 RSP: 002b:00007ffa754f9c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffa754fa6d4 RCX: 0000000000457089 RDX: 0000000020000780 RSI: 0000000040bc5311 RDI: 0000000000000005 RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d0580 R14: 00000000004bf3d0 R15: 0000000000000001 INFO: task syz-executor5:10216 blocked for more than 140 seconds. Not tainted 4.19.0-rc1+ #214 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D24952 10216 4688 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: 0033:0x457089 Code: 08 e8 3b a9 fb ff 48 8b 44 24 20 48 8b 4c 24 18 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 RSP: 002b:00007ffa754d8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffa754d96d4 RCX: 0000000000457089 RDX: 00000000200000c0 RSI: 00000000c08c5332 RDI: 000000000000000b RBP: 00000000009301e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d03b8 R14: 00000000004bf0e0 R15: 0000000000000002 INFO: task syz-executor5:10229 blocked for more than 140 seconds. Not tainted 4.19.0-rc1+ #214 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D25896 10229 4688 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: 0033:0x457089 Code: 08 e8 3b a9 fb ff 48 8b 44 24 20 48 8b 4c 24 18 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 RSP: 002b:00007ffa75454c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ffa754556d4 RCX: 0000000000457089 RDX: 00000000ffffff76 RSI: 0000000020000000 RDI: 000000000000000b RBP: 0000000000930460 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d7cc0 R14: 00000000004caaa4 R15: 0000000000000006 Showing all locks held in the system: 1 lock held by khungtaskd/792: #0: 000000005f5fedeb (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4436 1 lock held by rsyslogd/4543: 2 locks held by getty/4633: #0: 00000000ce93f1c2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000a3b66981 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4634: #0: 00000000ec41736b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000072334c90 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4635: #0: 00000000bac1dcb2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000f990dbbd (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4636: #0: 000000009fbeea7d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000046cb9069 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4637: #0: 0000000062fe1354 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000000cb049d0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4638: #0: 00000000917524d4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000008587ea5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4639: #0: 00000000a5c192d6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000004e695eab (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by syz-executor5/10169: 1 lock held by syz-executor5/10209: #0: 00000000cb66b740 (&client->ioctl_mutex){+.+.}, at: snd_seq_ioctl+0x221/0x440 sound/core/seq/seq_clientmgr.c:2137 1 lock held by syz-executor5/10216: #0: 00000000cb66b740 (&client->ioctl_mutex){+.+.}, at: snd_seq_ioctl+0x221/0x440 sound/core/seq/seq_clientmgr.c:2137 1 lock held by syz-executor5/10229: #0: 00000000cb66b740 (&client->ioctl_mutex){+.+.}, at: snd_seq_write+0x1f1/0x8d0 sound/core/seq/seq_clientmgr.c:1021 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 792 Comm: khungtaskd Not tainted 4.19.0-rc1+ #214 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:413 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 10169 Comm: syz-executor5 Not tainted 4.19.0-rc1+ #214 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:find_held_lock+0x1/0x1c0 kernel/locking/lockdep.c:3510 Code: 08 5d 00 48 8b 95 18 ff ff ff 48 8b b5 20 ff ff ff 4c 8b 85 28 ff ff ff 48 8b 85 30 ff ff ff e9 e9 f9 ff ff 0f 1f 44 00 00 55 <48> 89 e5 41 57 44 8d 7a ff 41 56 49 63 c7 49 89 f6 41 55 48 8d 04 RSP: 0018:ffff88018e83f7f8 EFLAGS: 00000002 RAX: 0000000000000002 RBX: 1ffff10031d07f06 RCX: ffff88018e83f850 RDX: 0000000000000002 RSI: ffffffff88861598 RDI: ffff88018efa4280 RBP: ffff88018e83f938 R08: 0000000000000000 R09: ffffed0039e23338 R10: ffffffff89b56820 R11: 0000000000000002 R12: ffff88018e83f910 R13: ffffffff88861598 R14: ffff88018efa4280 R15: ffff88018e83f850 FS: 00007ffa7551b700(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020c00000 CR3: 00000001d70d1000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_unlock_irqrestore+0x1f/0xc0 kernel/locking/spinlock.c:184 spin_unlock_irqrestore include/linux/spinlock.h:384 [inline] queueptr+0x99/0xb0 sound/core/seq/seq_queue.c:227 snd_seq_queue_is_used+0x18/0x70 sound/core/seq/seq_queue.c:536 snd_seq_client_enqueue_event+0x179/0x510 sound/core/seq/seq_clientmgr.c:945 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: 0033:0x457089 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:00007ffa7551ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ffa7551b6d4 RCX: 0000000000457089 RDX: 00000000ffffff76 RSI: 0000000020000000 RDI: 0000000000000005 RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d7cc0 R14: 00000000004caaa4 R15: 0000000000000000