INFO: task syz-executor6:25616 blocked for more than 120 seconds.
      Not tainted 4.4.132-g1a2b3e7 #43
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor6   D ffff8801b14ef460 26360 25616   3913 0x20020004
 ffff8801b14ef460 0000000000000081 ffff8801b5f72101 33b70683ae08289d
 ffff8801b14ef600 ffff8801db31fdb8 ffff8801db31fde0 ffff8801db31f4d8
 ffff8801db31f4c0 ffff8801bc043000 ffff8801b5f71800 0000000000000000
Call Trace:
 [<ffffffff838b220a>] schedule+0x7a/0x1b0 kernel/sched/core.c:3359
 [<ffffffff838bd621>] schedule_timeout+0x481/0x8b0 kernel/time/timer.c:1515
 [<ffffffff838b00ca>] io_schedule_timeout+0x1ba/0x390 kernel/sched/core.c:4941
 [<ffffffff838b345b>] io_schedule include/linux/sched.h:447 [inline]
 [<ffffffff838b345b>] bit_wait_io+0x1b/0xd0 kernel/sched/wait.c:595
 [<ffffffff838b2fc2>] __wait_on_bit_lock.part.4+0x92/0x140 kernel/sched/wait.c:434
 [<ffffffff838b3079>] __wait_on_bit_lock+0x9/0x10 kernel/sched/wait.c:427
 [<ffffffff8141ca5d>] __lock_page+0x17d/0x1f0 mm/filemap.c:888
 [<ffffffff815b915b>] lock_page include/linux/pagemap.h:458 [inline]
 [<ffffffff815b915b>] __generic_file_splice_read+0x7eb/0xbb0 fs/splice.c:412
 [<ffffffff815b9602>] generic_file_splice_read+0xe2/0x1c0 fs/splice.c:542
 [<ffffffff815b5757>] do_splice_to+0xf7/0x140 fs/splice.c:1154
 [<ffffffff815b59e2>] splice_direct_to_actor+0x242/0x830 fs/splice.c:1226
 [<ffffffff815b6173>] do_splice_direct+0x1a3/0x270 fs/splice.c:1337
 [<ffffffff8151ff14>] do_sendfile+0x4e4/0xb80 fs/read_write.c:1227
 [<ffffffff81522061>] C_SYSC_sendfile fs/read_write.c:1303 [inline]
 [<ffffffff81522061>] compat_SyS_sendfile+0xd1/0x160 fs/read_write.c:1292
 [<ffffffff81006d96>] do_syscall_32_irqs_on arch/x86/entry/common.c:392 [inline]
 [<ffffffff81006d96>] do_fast_syscall_32+0x326/0x8b0 arch/x86/entry/common.c:459
 [<ffffffff838c1b6a>] sysenter_flags_fixed+0xd/0x17
no locks held by syz-executor6/25616.
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.132-g1a2b3e7 #43
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffffffff84417840 task.stack: ffffffff84400000
RIP: 0010:[<ffffffff81195510>]  [<ffffffff81195510>] atomic_notifier_call_chain+0x0/0x140 include/linux/compiler.h:218
RSP: 0018:ffffffff84407e08  EFLAGS: 00000246
RAX: ffffffff84417840 RBX: 0000000000000002 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffffffff84483be0
RBP: ffffffff84407e18 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: fffffbfff074890c R15: ffffffff84a05b28
FS:  0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa873354140 CR3: 00000000b209d000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff8113047e dffffc0000000000 ffffffff84407e28 ffffffff8102728f
 ffffffff84407ed0 ffffffff8121bd49 fffffbfff09429e6 0000000000000200
 0000000041b58ab3 ffffffff841d89d4 ffffffff8121bae0 ffff8801db21f4c0
Call Trace:
 [<ffffffff8102728f>] __exit_idle arch/x86/kernel/process.c:247 [inline]
 [<ffffffff8102728f>] arch_cpu_idle_exit+0x1f/0x30 arch/x86/kernel/process.c:268
 [<ffffffff8121bd49>] cpu_idle_loop kernel/sched/idle.c:255 [inline]
 [<ffffffff8121bd49>] cpu_startup_entry+0x269/0x780 kernel/sched/idle.c:301
 [<ffffffff838ad371>] rest_init+0x188/0x18e init/main.c:410
 [<ffffffff84a4b8a1>] start_kernel+0x6b3/0x6e7 init/main.c:682
 [<ffffffff84a4a30f>] x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:196
 [<ffffffff84a4a450>] x86_64_start_kernel+0x13f/0x162 arch/x86/kernel/head64.c:185
Code: fa 4c 89 f6 e8 d2 e9 ff ff 48 89 df 41 89 c5 e8 b7 03 09 00 eb bd 4c 89 e7 e8 6d 3b 36 00 eb a4 90 66 2e 0f 1f 84 00 00 00 00 00 <55> 48 89 e5 41 55 49 89 d5 41 54 49 89 f4 53 48 89 fb 48 83 ec 
NMI backtrace for cpu 1
CPU: 1 PID: 491 Comm: khungtaskd Not tainted 4.4.132-g1a2b3e7 #43
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d9011800 task.stack: ffff8801d8e78000
RIP: 0010:[<ffffffff810bfe16>]  [<ffffffff810bfe16>] native_apic_mem_write arch/x86/include/asm/apic.h:94 [inline]
RIP: 0010:[<ffffffff810bfe16>]  [<ffffffff810bfe16>] __default_send_IPI_dest_field arch/x86/include/asm/ipi.h:119 [inline]
RIP: 0010:[<ffffffff810bfe16>]  [<ffffffff810bfe16>] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:61 [inline]
RIP: 0010:[<ffffffff810bfe16>]  [<ffffffff810bfe16>] flat_send_IPI_mask+0xf6/0x1a0 arch/x86/kernel/apic/apic_flat_64.c:69
RSP: 0018:ffff8801d8e7fcc8  EFLAGS: 00000046
RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300
RBP: ffff8801d8e7fcf0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000246
R13: 0000000000000003 R14: 0000000000000002 R15: ffffffff8446f7a0
FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa873354140 CR3: 00000000b209d000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff8446f7a0 ffffffff84a18a60 0000000000000007 fffffbfff0942bfc
 0000000000000040 ffff8801d8e7fd10 ffffffff810b5dd1 ffffffff83c0b1a0
 0000000000000003 ffff8801d8e7fd68 ffffffff81e19003 ffff8801b5f71800
Call Trace:
 [<ffffffff810b5dd1>] nmi_raise_cpu_backtrace+0x61/0x80 arch/x86/kernel/apic/hw_nmi.c:33
 [<ffffffff81e19003>] nmi_trigger_all_cpu_backtrace.cold.4+0x70/0xad lib/nmi_backtrace.c:85
 [<ffffffff810b5e74>] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 [<ffffffff8141a0b9>] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline]
 [<ffffffff8141a0b9>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff8141a0b9>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff8141a0b9>] watchdog.cold.1+0xd3/0xee kernel/hung_task.c:238
 [<ffffffff81190768>] kthread+0x268/0x300 kernel/kthread.c:211
 [<ffffffff838c0655>] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:510
Code: b3 5f ff f6 c4 10 75 e2 44 89 e8 c1 e0 18 89 04 25 10 b3 5f ff 44 89 f2 09 da 80 cf 04 41 83 fe 02 0f 44 d3 89 14 25 00 b3 5f ff <41> f7 c4 00 02 00 00 75 1a 4c 89 e7 57 9d 0f 1f 44 00 00 e8 f2