INFO: task syz-executor6:7097 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-executor6   D ffff8801d738f5c0 28056  7097   3872 0x00000004
 ffff8801d738f5c0 ffff8800b8c10038 ffffe8ffffc01c40 ffff8800b8c10030
 ffff8801d738f598 ffff8801d738f500 ffff8801db21fdb8 ffff8801db21fde0
 ffff8801db21f4d8 ffff8801d7bb3000 ffff8801d6bb0000 0000000000000000
Call Trace:
 [<ffffffff8376550a>] schedule+0x7a/0x1b0 kernel/sched/core.c:3353
 [<ffffffff83770820>] schedule_timeout+0x3a0/0x970 kernel/time/timer.c:1515
 [<ffffffff8376349e>] io_schedule_timeout+0x1be/0x390 kernel/sched/core.c:4935
 [<ffffffff815ddc5d>] io_schedule include/linux/sched.h:447 [inline]
 [<ffffffff815ddc5d>] dio_await_one fs/direct-io.c:449 [inline]
 [<ffffffff815ddc5d>] dio_await_completion fs/direct-io.c:503 [inline]
 [<ffffffff815ddc5d>] do_blockdev_direct_IO+0x476d/0x8810 fs/direct-io.c:1313
 [<ffffffff815e1dae>] __blockdev_direct_IO+0xae/0xe0 fs/direct-io.c:1342
 [<ffffffff815d0ae2>] blkdev_direct_IO+0xb2/0xe0 fs/block_dev.c:167
 [<ffffffff81423c10>] generic_file_read_iter+0x360/0x1160 mm/filemap.c:1791
 [<ffffffff815d1b45>] blkdev_read_iter+0x105/0x170 fs/block_dev.c:1679
 [<ffffffff8151d129>] new_sync_read fs/read_write.c:422 [inline]
 [<ffffffff8151d129>] __vfs_read+0x339/0x440 fs/read_write.c:434
 [<ffffffff8151ed93>] vfs_read+0x123/0x3a0 fs/read_write.c:454
 [<ffffffff815216d9>] SYSC_read fs/read_write.c:569 [inline]
 [<ffffffff815216d9>] SyS_read+0xd9/0x1b0 fs/read_write.c:562
 [<ffffffff8377365f>] entry_SYSCALL_64_fastpath+0x1c/0x98
no locks held by syz-executor6/7097.
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: ffff8800baca3000 task.stack: ffff8800bac58000
RIP: 0010:[<ffffffff810c3e67>]  [<ffffffff810c3e67>] native_apic_mem_write arch/x86/include/asm/apic.h:94 [inline]
RIP: 0010:[<ffffffff810c3e67>]  [<ffffffff810c3e67>] __default_send_IPI_dest_field arch/x86/include/asm/ipi.h:119 [inline]
RIP: 0010:[<ffffffff810c3e67>]  [<ffffffff810c3e67>] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:61 [inline]
RIP: 0010:[<ffffffff810c3e67>]  [<ffffffff810c3e67>] flat_send_IPI_mask+0xf7/0x1a0 arch/x86/kernel/apic/apic_flat_64.c:69
RSP: 0018:ffff8800bac5fcb8  EFLAGS: 00000046
RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300
RBP: ffff8800bac5fce0 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: 00007fea706639b8 CR3: 00000001c7952000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff8426f420 ffffffff847efb00 fffffbfff08fda14 dffffc0000000000
 ffff8801db31bca0 ffff8800bac5fd00 ffffffff810b999b ffffffff839f63c0
 0000000000000003 ffff8800bac5fd60 ffffffff81d0ef94 0000000000000000
Call Trace:
 [<ffffffff810b999b>] nmi_raise_cpu_backtrace+0x5b/0x70 arch/x86/kernel/apic/hw_nmi.c:33
 [<ffffffff81d0ef94>] nmi_trigger_all_cpu_backtrace+0x4a4/0x550 lib/nmi_backtrace.c:85
 [<ffffffff810b9a34>] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 [<ffffffff81368c5a>] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline]
 [<ffffffff81368c5a>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81368c5a>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81368c5a>] watchdog+0x6fa/0xae0 kernel/hung_task.c:238
 [<ffffffff81190788>] kthread+0x268/0x300 kernel/kthread.c:211
 [<ffffffff83773a85>] 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:[<ffffffff812379ea>]  [<ffffffff812379ea>] __lock_acquire+0x5da/0x4b50 kernel/locking/lockdep.c:3092
RSP: 0018:ffff8801d9b5fb80  EFLAGS: 00000002
RAX: dffffc0000000000 RBX: ffff8801d9b49800 RCX: 0000000000000000
RDX: 1ffffffff0857b7c RSI: 0000000000000001 RDI: ffffffff842bdbe0
RBP: ffff8801d9b5fd18 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 1ffff1003b36bf82 R12: 0000000000000000
R13: ffff8801d9b49800 R14: ffffffff842bdbe0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1617056000 CR3: 00000001c7952000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 00000000810b07fa 0000000000000046 ffff8801d9b4a0d0 ffff8801d9b5fbd8
 ffffffff812aec17 ffff8801d9b49800 0000000000000046 0000000000000086
 ffff8801db319640 0000003829d51900 ffff8801d9b5fbe0 ffff8801d9b4a0e8
Call Trace:
 [<ffffffff8123d7ce>] lock_acquire+0x15e/0x460 kernel/locking/lockdep.c:3592
 [<ffffffff81195618>] rcu_lock_acquire include/linux/rcupdate.h:477 [inline]
 [<ffffffff81195618>] rcu_read_lock include/linux/rcupdate.h:861 [inline]
 [<ffffffff81195618>] __atomic_notifier_call_chain kernel/notifier.c:182 [inline]
 [<ffffffff81195618>] atomic_notifier_call_chain+0x48/0x140 kernel/notifier.c:193
 [<ffffffff8112df2e>] idle_notifier_call_chain+0x1e/0x30 kernel/cpu.c:865
 [<ffffffff8102939f>] __exit_idle arch/x86/kernel/process.c:247 [inline]
 [<ffffffff8102939f>] arch_cpu_idle_exit+0x1f/0x30 arch/x86/kernel/process.c:268
 [<ffffffff812217d5>] cpu_idle_loop kernel/sched/idle.c:255 [inline]
 [<ffffffff812217d5>] cpu_startup_entry+0x265/0x8f0 kernel/sched/idle.c:301
 [<ffffffff810adc64>] start_secondary+0x304/0x3e0 arch/x86/kernel/smpboot.c:242
Code: 5c 41 5d 41 5e 41 5f 5d c3 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 80 3c 02 00 0f 85 94 32 00 00 49 81 3e e0 38 a2 84 <41> ba 00 00 00 00 45 0f 45 d0 41 83 fc 01 0f 87 59 fb ff ff 48