INFO: task syz-executor5:10371 blocked for more than 140 seconds. Not tainted 4.20.0-rc2+ #236 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D25288 10371 6212 0x20020004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472 schedule+0xfe/0x460 kernel/sched/core.c:3516 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3574 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0xaff/0x16f0 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 snd_seq_ioctl+0x221/0x440 sound/core/seq/seq_clientmgr.c:2137 snd_seq_ioctl_compat+0x16c/0x2d0 sound/core/seq/seq_compat.c:123 __do_compat_sys_ioctl fs/compat_ioctl.c:1052 [inline] __se_compat_sys_ioctl fs/compat_ioctl.c:998 [inline] __ia32_compat_sys_ioctl+0x20e/0x630 fs/compat_ioctl.c:998 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline] do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f60a29 Code: Bad RIP value. RSP: 002b:00000000f5f3b0cc EFLAGS: 00000296 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000c02c5341 RDX: 0000000020000680 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/1008: #0: 00000000ffa249b5 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 1 lock held by rsyslogd/5918: #0: 000000005d9ae769 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/6008: #0: 00000000eb0ba805 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000b8357459 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6009: #0: 0000000079a6fd7f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000814b9922 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6010: #0: 000000002da15a8e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000007726a376 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6011: #0: 0000000076759e54 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000002735e401 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6012: #0: 00000000be7850ae (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000016beb69 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6013: #0: 000000001e368f8a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000007f4da5bc (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6014: #0: 00000000534b6205 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000004f08fb14 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by syz-executor5/10358: 1 lock held by syz-executor5/10371: #0: 0000000025b32b21 (&client->ioctl_mutex){+.+.}, at: snd_seq_ioctl+0x221/0x440 sound/core/seq/seq_clientmgr.c:2137 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1008 Comm: khungtaskd Not tainted 4.20.0-rc2+ #236 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:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xb51/0x1060 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: 1.071 msecs NMI backtrace for cpu 1 CPU: 1 PID: 10358 Comm: syz-executor5 Not tainted 4.20.0-rc2+ #236 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__wrmsr arch/x86/include/asm/msr.h:105 [inline] RIP: 0010:native_write_msr+0xa/0x30 arch/x86/include/asm/msr.h:162 Code: 5d c3 0f 21 c8 5d c3 0f 21 d0 5d c3 0f 21 d8 5d c3 0f 21 f0 5d c3 0f 0b 0f 1f 84 00 00 00 00 00 55 89 f9 89 f0 48 89 e5 0f 30 <0f> 1f 44 00 00 5d c3 48 c1 e2 20 89 f6 48 09 d6 31 d2 e8 2f a4 6f RSP: 0018:ffff8881daf07d30 EFLAGS: 00000046 RAX: 000000000000012d RBX: 0000000000000838 RCX: 0000000000000838 RDX: 0000000000000000 RSI: 000000000000012d RDI: 0000000000000838 RBP: ffff8881daf07d30 R08: ffff888189512380 R09: 0000000000000006 R10: fffffbfff14a4009 R11: 0000000000000001 R12: 000000000000012d R13: 0000000000000000 R14: 0000000000000000 R15: 7fffffffffffffff FS: 0000000000000000(0000) GS:ffff8881daf00000(0063) knlGS:00000000f5f5cb40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001c74d2000 CR4: 00000000001406e0 Call Trace: paravirt_write_msr arch/x86/include/asm/paravirt.h:174 [inline] native_apic_msr_write+0x5a/0x80 arch/x86/include/asm/apic.h:209 apic_write arch/x86/include/asm/apic.h:397 [inline] lapic_next_event+0x5a/0x90 arch/x86/kernel/apic/apic.c:466 clockevents_program_event+0x251/0x370 kernel/time/clockevents.c:344 tick_program_event+0xb7/0x130 kernel/time/tick-oneshot.c:48 hrtimer_interrupt+0x368/0x780 kernel/time/hrtimer.c:1531 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1034 [inline] smp_apic_timer_interrupt+0x1a1/0x760 arch/x86/kernel/apic/apic.c:1059 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:804 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:761 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xaf/0xd0 kernel/locking/spinlock.c:184 Code: 70 fb 51 89 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 28 48 83 3d 18 4e 82 01 00 74 15 48 89 df 57 9d <0f> 1f 44 00 00 eb ad e8 9c cf 30 f9 eb bb 0f 0b 0f 0b e8 aa 27 f3 RSP: 0018:ffff888186eb7670 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: 0000000000000286 RCX: 1ffff110312a2584 RDX: 1ffffffff12a3f6e RSI: 0000000000000000 RDI: 0000000000000286 RBP: ffff888186eb7680 R08: ffff888189512c20 R09: 0000000000000006 R10: 0000000000000000 R11: ffff888189512380 R12: ffff8881cc572380 R13: ffffc900135bbd90 R14: 1ffff11030dd6ef5 R15: ffff8881cc572300 spin_unlock_irqrestore include/linux/spinlock.h:384 [inline] snd_seq_cell_alloc.isra.1+0x5a3/0x740 sound/core/seq/seq_memory.c:283 snd_seq_event_dup+0x194/0xaa0 sound/core/seq/seq_memory.c:312 snd_seq_client_enqueue_event+0x25b/0x510 sound/core/seq/seq_clientmgr.c:951 snd_seq_write+0x3f1/0x8d0 sound/core/seq/seq_clientmgr.c:1074 __vfs_write+0x119/0x9f0 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] __ia32_sys_write+0x71/0xb0 fs/read_write.c:607 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline] do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f60a29 Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000f5f5c0cc EFLAGS: 00000296 ORIG_RAX: 0000000000000004 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000020042f70 RDX: 00000000ffffffbd RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000