ALSA: seq fatal error: cannot create timer (-22) INFO: task syz-executor7:11187 blocked for more than 140 seconds. Not tainted 4.18.0-next-20180824+ #47 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor7 D25864 11187 4482 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 __rwsem_down_write_failed_common+0x98b/0x1650 kernel/locking/rwsem-xadd.c:566 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595 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_nested+0xae/0x130 kernel/locking/rwsem.c:194 inode_lock_nested include/linux/fs.h:805 [inline] do_unlinkat+0x3d8/0xa30 fs/namei.c:4049 __do_sys_unlink fs/namei.c:4110 [inline] __se_sys_unlink fs/namei.c:4108 [inline] __x64_sys_unlink+0x42/0x50 fs/namei.c:4108 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:00007f5e37b88c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 00007f5e37b896d4 RCX: 0000000000457089 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000300 RBP: 00000000009301e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d6c80 R14: 00000000004c7a6c R15: 0000000000000002 Showing all locks held in the system: 1 lock held by khungtaskd/776: #0: 000000008916cdf5 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4436 1 lock held by rsyslogd/4340: #0: 0000000051d6cac1 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/4431: #0: 00000000cdf12b4d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000685a75ed (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4432: #0: 00000000b72f49d9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000001d552d18 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4433: #0: 00000000545f4569 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000e326ec63 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4434: #0: 00000000bd7ab1a6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000001523ee70 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4435: #0: 0000000067a46795 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000001b8f0758 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4436: #0: 000000003a1ae581 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000c865b733 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4437: #0: 00000000f61cd2a7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000074cc05a3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 3 locks held by syz-executor7/11134: #0: 0000000018b52c77 (sb_writers#17){.+.+}, at: sb_start_write include/linux/fs.h:1598 [inline] #0: 0000000018b52c77 (sb_writers#17){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360 #1: 0000000086b8a3bc (&sb->s_type->i_mutex_key#24/1){+.+.}, at: inode_lock_nested include/linux/fs.h:805 [inline] #1: 0000000086b8a3bc (&sb->s_type->i_mutex_key#24/1){+.+.}, at: do_unlinkat+0x3d8/0xa30 fs/namei.c:4049 #2: 00000000844e98e6 (&sb->s_type->i_mutex_key#24){+.+.}, at: inode_lock include/linux/fs.h:765 [inline] #2: 00000000844e98e6 (&sb->s_type->i_mutex_key#24){+.+.}, at: vfs_unlink+0xd1/0x510 fs/namei.c:3991 2 locks held by syz-executor7/11187: #0: 0000000018b52c77 (sb_writers#17){.+.+}, at: sb_start_write include/linux/fs.h:1598 [inline] #0: 0000000018b52c77 (sb_writers#17){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360 #1: 0000000086b8a3bc (&sb->s_type->i_mutex_key#24/1){+.+.}, at: inode_lock_nested include/linux/fs.h:805 [inline] #1: 0000000086b8a3bc (&sb->s_type->i_mutex_key#24/1){+.+.}, at: do_unlinkat+0x3d8/0xa30 fs/namei.c:4049 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 776 Comm: khungtaskd Not tainted 4.18.0-next-20180824+ #47 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: 0 Comm: swapper/0 Not tainted 4.18.0-next-20180824+ #47 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:lockdep_hardirqs_off+0xb/0x2c0 kernel/locking/lockdep.c:2888 Code: e8 7a 58 5c 00 e9 c1 fe ff ff e8 70 58 5c 00 e9 37 fe ff ff 90 66 2e 0f 1f 84 00 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 55 <48> 89 e5 41 55 49 89 fd 48 c7 c7 a0 d9 2a 88 48 89 fa 41 54 48 c1 RSP: 0018:ffff8801db007ae0 EFLAGS: 00000093 RAX: dffffc0000000000 RBX: 1ffff1003b600f61 RCX: ffffffff8182dcd7 RDX: 0000000000000000 RSI: ffffffff8182dd0f RDI: ffffffff816bd263 RBP: ffff8801db007b90 R08: ffffffff87e75e00 R09: ffffed003b6046de R10: ffffed003b6046de R11: ffff8801db0236f3 R12: 0000000000000001 R13: ffff8801db0265ec R14: ffff8801db007c70 R15: ffffffff87f1bc60 FS: 0000000000000000(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000001e45000 CR3: 00000001b01a8000 CR4: 00000000001406f0 DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: seqcount_lockdep_reader_access include/linux/seqlock.h:80 [inline] read_seqcount_begin include/linux/seqlock.h:164 [inline] ktime_get+0x123/0x440 kernel/time/timekeeping.c:754 tick_nohz_start_idle kernel/time/tick-sched.c:537 [inline] tick_nohz_irq_exit+0x7e/0x100 kernel/time/tick-sched.c:1009 tick_irq_exit kernel/softirq.c:394 [inline] irq_exit+0x1c0/0x210 kernel/softirq.c:414 scheduler_ipi+0x53c/0xa50 kernel/sched/core.c:1780 smp_reschedule_interrupt+0xfd/0x5e0 arch/x86/kernel/smp.c:278 reschedule_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:891 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:56 Code: c7 48 89 45 d8 e8 2a 25 05 fb 48 8b 45 d8 e9 d2 fe ff ff 48 89 df e8 19 25 05 fb eb 8a 90 90 90 90 90 90 90 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 90 90 90 90 90 RSP: 0018:ffffffff87e07bb8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff02 RAX: dffffc0000000000 RBX: 1ffffffff0fc0f7b RCX: 0000000000000000 RDX: 1ffffffff0fe3790 RSI: 0000000000000001 RDI: ffffffff87f1bc80 RBP: ffffffff87e07bb8 R08: ffffffff87e75e00 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff87e07c78 R14: 0000000000000000 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0xc2/0x410 arch/x86/kernel/process.c:498 arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:489 default_idle_call+0x6d/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x3aa/0x580 kernel/sched/idle.c:262 cpu_startup_entry+0x10c/0x120 kernel/sched/idle.c:368 rest_init+0xe1/0xe4 init/main.c:442 start_kernel+0x913/0x94e init/main.c:739 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:452 x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:433 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242