INFO: task syz-executor4:21632 blocked for more than 120 seconds.
      Not tainted 4.4.111-gc2f631b #20
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor4   D ffff8801ceaa7458 26424 21632   5074 0x20020004
 ffff8801ceaa7458 ffff8801ceaa73f0 e5321689db9129f4 ffff8801ceaa7500
 ffff8801ceaa7630 ffff8801d9c12c00 ffff8801db31fdb8 ffff8801db31fde0
 ffff8801db31f4d8 ffff8800bb1c17c0 ffff8800bb3fdf00 ffff8801ceaa0000
Call Trace:
 [<ffffffff8376790a>] schedule+0x9a/0x1c0 kernel/sched/core.c:3351
 [<ffffffff83772ba1>] schedule_timeout+0x3a1/0x970 kernel/time/timer.c:1508
 [<ffffffff8376588e>] io_schedule_timeout+0x1be/0x390 kernel/sched/core.c:4932
 [<ffffffff83768bbb>] io_schedule include/linux/sched.h:447 [inline]
 [<ffffffff83768bbb>] bit_wait_io+0x1b/0xc0 kernel/sched/wait.c:595
 [<ffffffff837686ff>] __wait_on_bit_lock+0x8f/0x140 kernel/sched/wait.c:434
 [<ffffffff8141ccbd>] __lock_page+0x18d/0x1f0 mm/filemap.c:888
 [<ffffffff815b9110>] lock_page include/linux/pagemap.h:458 [inline]
 [<ffffffff815b9110>] __generic_file_splice_read+0x730/0xb00 fs/splice.c:412
 [<ffffffff815b95c2>] generic_file_splice_read+0xe2/0x1c0 fs/splice.c:542
 [<ffffffff815b58c5>] do_splice_to+0xf5/0x140 fs/splice.c:1154
 [<ffffffff815b5b60>] splice_direct_to_actor+0x250/0x830 fs/splice.c:1226
 [<ffffffff815b62e7>] do_splice_direct+0x1a7/0x270 fs/splice.c:1337
 [<ffffffff815202ac>] do_sendfile+0x54c/0xd30 fs/read_write.c:1227
 [<ffffffff81522481>] C_SYSC_sendfile fs/read_write.c:1303 [inline]
 [<ffffffff81522481>] compat_SyS_sendfile+0xd1/0x160 fs/read_write.c:1292
 [<ffffffff81006d84>] do_syscall_32_irqs_on arch/x86/entry/common.c:390 [inline]
 [<ffffffff81006d84>] do_fast_syscall_32+0x314/0x890 arch/x86/entry/common.c:457
 [<ffffffff837772aa>] sysenter_flags_fixed+0xd/0x17
1 lock held by syz-executor4/21632:
 #0:  (sb_writers#6){.+.+.+}, at: [<ffffffff81520644>] file_start_write include/linux/fs.h:2523 [inline]
 #0:  (sb_writers#6){.+.+.+}, at: [<ffffffff81520644>] do_sendfile+0x8e4/0xd30 fs/read_write.c:1226
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.111-gc2f631b #20
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffffffff84217840 task.stack: ffffffff84200000
RIP: 0010:[<ffffffff810d0526>]  [<ffffffff810d0526>] native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:49
RSP: 0018:ffffffff84207da0  EFLAGS: 00000246
RAX: 0000000000000007 RBX: ffffffff847dc308 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff842180ac
RBP: ffffffff84207da0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7f382939b8 CR3: 00000001d43c8000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff84207dd8 ffffffff81027e15 ffffffff84208000 ffffffff847dc308
 0000000000000000 0000000000000000 dffffc0000000000 ffffffff84207de8
 ffffffff8102938a ffffffff84207e00 ffffffff81220508 ffffffff84208000
Call Trace:
 [<ffffffff81027e15>] arch_safe_halt arch/x86/include/asm/paravirt.h:117 [inline]
 [<ffffffff81027e15>] default_idle+0x55/0x3c0 arch/x86/kernel/process.c:291
 [<ffffffff8102938a>] arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:282
 [<ffffffff81220508>] default_idle_call+0x48/0x70 kernel/sched/idle.c:93
 [<ffffffff81220c15>] cpuidle_idle_call kernel/sched/idle.c:157 [inline]
 [<ffffffff81220c15>] cpu_idle_loop kernel/sched/idle.c:253 [inline]
 [<ffffffff81220c15>] cpu_startup_entry+0x605/0x820 kernel/sched/idle.c:301
 [<ffffffff83762959>] rest_init+0x189/0x190 init/main.c:410
 [<ffffffff84820811>] start_kernel+0x6b9/0x6ee init/main.c:682
 [<ffffffff8481f312>] x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:196
 [<ffffffff8481f454>] x86_64_start_kernel+0x140/0x163 arch/x86/kernel/head64.c:185
Code: 00 00 00 00 00 55 48 89 e5 fa 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 66 0f 1f 84 
NMI backtrace for cpu 1
CPU: 1 PID: 486 Comm: khungtaskd Not tainted 4.4.111-gc2f631b #20
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d944df00 task.stack: ffff8800bac60000
RIP: 0010:[<ffffffff810c39c7>]  [<ffffffff810c39c7>] native_apic_mem_write arch/x86/include/asm/apic.h:94 [inline]
RIP: 0010:[<ffffffff810c39c7>]  [<ffffffff810c39c7>] __default_send_IPI_dest_field arch/x86/include/asm/ipi.h:119 [inline]
RIP: 0010:[<ffffffff810c39c7>]  [<ffffffff810c39c7>] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:61 [inline]
RIP: 0010:[<ffffffff810c39c7>]  [<ffffffff810c39c7>] flat_send_IPI_mask+0xf7/0x1a0 arch/x86/kernel/apic/apic_flat_64.c:69
RSP: 0018:ffff8800bac67cb8  EFLAGS: 00000046
RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300
RBP: ffff8800bac67ce0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000246
R13: 0000000000000003 R14: ffffffff8426ea20 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f82048b9000 CR3: 00000001d43c8000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff8426ea20 ffffffff847ee200 000000000001bca0 0000000000000040
 dffffc0000000000 ffff8800bac67d00 ffffffff810b94fb ffffffff839f56e0
 0000000000000003 ffff8800bac67d60 ffffffff81d10097 ffffffff81419f63
Call Trace:
 [<ffffffff810b94fb>] nmi_raise_cpu_backtrace+0x5b/0x70 arch/x86/kernel/apic/hw_nmi.c:33
 [<ffffffff81d10097>] nmi_trigger_all_cpu_backtrace+0x4a7/0x550 lib/nmi_backtrace.c:85
 [<ffffffff810b9594>] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 [<ffffffff81367dca>] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline]
 [<ffffffff81367dca>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81367dca>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81367dca>] watchdog+0x6fa/0xae0 kernel/hung_task.c:238
 [<ffffffff811908e8>] kthread+0x268/0x300 kernel/kthread.c:211
 [<ffffffff83775d1f>] ret_from_fork+0x3f/0x70 arch/x86/entry/entry_64.S:494
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 2b 24 17 00 4c 89 e7 57 9d 0f 1f