INFO: task syz-executor5:4891 blocked for more than 120 seconds. Not tainted 4.4.115-g55a366596 #14 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D ffff8801d103f8c8 28728 4891 3721 0x00000002 ffff8801d103f8c8 0000000000000000 0000000000000000 0000000000000000 0000000000000001 ffff8801d103f800 ffff8801db31fdb8 ffff8801db31fde0 ffff8801db31f4d8 ffff8801d9b49800 ffff8801cfba3000 0000000000000000 Call Trace: [] schedule+0x7a/0x1b0 kernel/sched/core.c:3353 [] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3386 [] __mutex_lock_common kernel/locking/mutex.c:582 [inline] [] mutex_lock_nested+0x306/0x850 kernel/locking/mutex.c:621 [] odev_release+0x4a/0x70 sound/core/seq/oss/seq_oss.c:151 [] __fput+0x233/0x6d0 fs/file_table.c:208 [] ____fput+0x15/0x20 fs/file_table.c:244 [] task_work_run+0x104/0x180 kernel/task_work.c:115 [] exit_task_work include/linux/task_work.h:21 [inline] [] do_exit+0x82a/0x2a10 kernel/exit.c:755 [] do_group_exit+0x108/0x320 kernel/exit.c:885 [] get_signal+0x4f2/0x1550 kernel/signal.c:2317 [] do_signal+0x8b/0x1d40 arch/x86/kernel/signal.c:712 [] exit_to_usermode_loop+0x11a/0x160 arch/x86/entry/common.c:247 [] prepare_exit_to_usermode arch/x86/entry/common.c:282 [inline] [] syscall_return_slowpath+0x1b5/0x1f0 arch/x86/entry/common.c:347 [] int_ret_from_sys_call+0x25/0xa3 INFO: lockdep is turned off. Sending NMI to all CPUs: NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.115-g55a366596 #14 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffffffff84217840 task.stack: ffffffff84200000 RIP: 0010:[] [] __read_once_size include/linux/compiler.h:218 [inline] RIP: 0010:[] [] atomic_read arch/x86/include/asm/atomic.h:27 [inline] RIP: 0010:[] [] static_key_count include/linux/jump_label.h:172 [inline] RIP: 0010:[] [] static_key_false include/linux/jump_label.h:182 [inline] RIP: 0010:[] [] perf_event_task_sched_out include/linux/perf_event.h:948 [inline] RIP: 0010:[] [] prepare_task_switch kernel/sched/core.c:2612 [inline] RIP: 0010:[] [] context_switch kernel/sched/core.c:2770 [inline] RIP: 0010:[] [] __schedule+0x935/0x1ca0 kernel/sched/core.c:3324 RSP: 0018:ffffffff84207d78 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff8801db21f4c0 RCX: ffff8800b24e8000 RDX: 0000000000000000 RSI: ffff8800b24e8000 RDI: ffffffff847ed3f8 RBP: ffffffff84207df0 R08: ffffffff83844400 R09: 0000000000000001 R10: dffffc0000000000 R11: 1ffffffff0840f76 R12: 0000000000000000 R13: 00000038764890f2 R14: ffff8801db21fde8 R15: ffffffff847ebc38 FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa7bd739000 CR3: 00000001cec92000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: 0000003829720966 ffffffff84207dc8 ffffffff812d51c6 ffffffff84207dd0 ffffffff81d63b00 ffff8801db21fdb8 ffff8801db21fde0 ffff8801db21f4d8 ffff8800b24e8000 ffffffff84217840 ffffffff84217840 dffffc0000000000 Call Trace: [] schedule+0x7a/0x1b0 kernel/sched/core.c:3353 [] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3386 [] cpu_idle_loop kernel/sched/idle.c:279 [inline] [] cpu_startup_entry+0x2c0/0x8f0 kernel/sched/idle.c:301 [] rest_init+0x189/0x190 init/main.c:410 [] start_kernel+0x6b9/0x6ee init/main.c:682 [] x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:196 [] x86_64_start_kernel+0x140/0x163 arch/x86/kernel/head64.c:185 Code: 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 43 11 00 00 8b 05 a3 85 08 01 <85> c0 0f 8f 30 08 00 00 48 8b 45 c8 48 8d 78 28 48 b8 00 00 00 NMI backtrace for cpu 1 CPU: 1 PID: 485 Comm: khungtaskd Not tainted 4.4.115-g55a366596 #14 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8800bac19800 task.stack: ffff8800bb3e0000 RIP: 0010:[] [] native_apic_mem_write arch/x86/include/asm/apic.h:94 [inline] RIP: 0010:[] [] __default_send_IPI_dest_field arch/x86/include/asm/ipi.h:119 [inline] RIP: 0010:[] [] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:61 [inline] RIP: 0010:[] [] flat_send_IPI_mask+0xf7/0x1a0 arch/x86/kernel/apic/apic_flat_64.c:69 RSP: 0018:ffff8800bb3e7cb8 EFLAGS: 00000046 RAX: 0000000003000000 RBX: 0000000000000c00 RCX: ffffffff8126a2f2 RDX: 0000000000000c00 RSI: 0000000000000002 RDI: ffffffffff5fb300 RBP: ffff8800bb3e7ce0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: fffffbfff0ad7e2c R12: 0000000000000246 R13: 0000000000000003 R14: ffffffff8426f3a0 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c422ccf010 CR3: 00000001cec92000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffffffff8426f3a0 ffffffff847ef7c0 fffffbfff08fd9ac dffffc0000000000 ffff8801db31bca0 ffff8800bb3e7d00 ffffffff810b99eb ffffffff839f6200 0000000000000003 ffff8800bb3e7d60 ffffffff81d0ecf4 0000000000000001 Call Trace: [] nmi_raise_cpu_backtrace+0x5b/0x70 arch/x86/kernel/apic/hw_nmi.c:33 [] nmi_trigger_all_cpu_backtrace+0x4a4/0x550 lib/nmi_backtrace.c:85 [] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 [] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline] [] check_hung_task kernel/hung_task.c:125 [inline] [] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline] [] watchdog+0x6fa/0xae0 kernel/hung_task.c:238 [] kthread+0x268/0x300 kernel/kthread.c:211 [] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:506 Code: b3 5f ff f6 c4 10 75 e1 44 89 e8 c1 e0 18 89 04 25 10 b3 5f ff 44 89 fa 09 da 80 cf 04 41 83 ff 02 0f 44 d3 89 14 25 00 b3 5f ff <41> f7 c4 00 02 00 00 74 1a e8 7b 2f 17 00 4c 89 e7 57 9d 0f 1f