INFO: task syz-executor0:8562 blocked for more than 120 seconds. Not tainted 4.4.119-g855ea74 #27 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D ffff8800ab6275c0 28056 8562 3842 0x00000004 ffff8800ab6275c0 ffff8800abbe0038 ffffe8ffffd13e00 ffff8800abbe0030 ffff8800ab627598 ffff8800ab627500 ffff8801db31fdb8 ffff8801db31fde0 ffff8801db31f4d8 ffff8800ab563000 ffff8800abbc1800 0000000000000000 Call Trace: [] schedule+0x7a/0x1b0 kernel/sched/core.c:3353 [] schedule_timeout+0x3a0/0x970 kernel/time/timer.c:1515 [] io_schedule_timeout+0x1be/0x390 kernel/sched/core.c:4935 [] io_schedule include/linux/sched.h:447 [inline] [] dio_await_one fs/direct-io.c:449 [inline] [] dio_await_completion fs/direct-io.c:503 [inline] [] do_blockdev_direct_IO+0x476d/0x8810 fs/direct-io.c:1313 [] __blockdev_direct_IO+0xae/0xe0 fs/direct-io.c:1342 [] blkdev_direct_IO+0xb2/0xe0 fs/block_dev.c:167 [] generic_file_read_iter+0x360/0x1160 mm/filemap.c:1791 [] blkdev_read_iter+0x105/0x170 fs/block_dev.c:1679 [] new_sync_read fs/read_write.c:422 [inline] [] __vfs_read+0x339/0x440 fs/read_write.c:434 [] vfs_read+0x123/0x3a0 fs/read_write.c:454 [] SYSC_read fs/read_write.c:569 [inline] [] SyS_read+0xd9/0x1b0 fs/read_write.c:562 [] entry_SYSCALL_64_fastpath+0x1c/0x98 no locks held by syz-executor0/8562. Sending NMI to all CPUs: NMI backtrace for cpu 0 CPU: 0 PID: 485 Comm: khungtaskd Not tainted 4.4.119-g855ea74 #27 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8800bac61800 task.stack: ffff8800bac00000 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:ffff8800bac07cb8 EFLAGS: 00000046 RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000 RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300 RBP: ffff8800bac07ce0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000246 R13: 0000000000000003 R14: ffffffff8426f420 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1729139b8 CR3: 00000000b3df0000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffffffff8426f420 ffffffff847efb00 fffffbfff08fda14 dffffc0000000000 ffff8801db31bca0 ffff8800bac07d00 ffffffff810b999b ffffffff839f63c0 0000000000000003 ffff8800bac07d60 ffffffff81d0ef94 0000000000000000 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 6b 2f 17 00 4c 89 e7 57 9d 0f 1f NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.4.119-g855ea74 #27 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801d9b49800 task.stack: ffff8801d9b58000 RIP: 0010:[] [] lock_acquire+0xd6/0x460 kernel/locking/lockdep.c:3590 RSP: 0018:ffff8801d9b5fd28 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffffffff842bdbe0 RCX: 0000000000000000 RDX: ffff8801d9b49800 RSI: 0000000000000000 RDI: ffff8801d9b4a0cc RBP: ffff8801d9b5fda0 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff838444e0 R11: ffffffff847ebf78 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000002 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3ef403a000 CR3: 00000000b3df0000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: 0000000000000000 0000000000000000 0000000000000007 0000000000000000 ffff8801d9b5fd88 ffffffff81d63deb ffff8801d9b4a0cc ffff8801d9b5fda0 0000000000000000 0000000000000246 ffffffff84283ba0 0000000000000002 Call Trace: [] rcu_lock_acquire include/linux/rcupdate.h:477 [inline] [] rcu_read_lock include/linux/rcupdate.h:861 [inline] [] __atomic_notifier_call_chain kernel/notifier.c:182 [inline] [] atomic_notifier_call_chain+0x48/0x140 kernel/notifier.c:193 [] idle_notifier_call_chain+0x1e/0x30 kernel/cpu.c:865 [] __exit_idle arch/x86/kernel/process.c:247 [inline] [] arch_cpu_idle_exit+0x1f/0x30 arch/x86/kernel/process.c:268 [] cpu_idle_loop kernel/sched/idle.c:255 [inline] [] cpu_startup_entry+0x265/0x8f0 kernel/sched/idle.c:301 [] start_secondary+0x304/0x3e0 arch/x86/kernel/smpboot.c:242 Code: 03 38 c8 7c 08 84 c9 0f 85 a7 02 00 00 8b 05 da f9 59 03 49 c7 c2 e0 44 84 83 c7 82 cc 08 00 00 01 00 00 00 4c 8b 1d 9a 6d 60 02 <85> c0 0f 8f 1a 01 00 00 48 ba 00 00 00 00 00 fc ff df 4c 89 d0