Buffer I/O error on dev loop0, logical block 10, lost async page write
INFO: task syz-executor1:14324 blocked for more than 120 seconds.
      Not tainted 4.4.120-gd63fdf6 #28
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor1   D ffff8801d7a07020 26816 14324   3791 0x00000004
 ffff8801d7a07020 ffff8800b90f7a00 ffff8801d7a06fd8 ffffffff815c40d1
 ffff8800b90f7a00 dffffc0000000000 ffff8801db21fdb8 ffff8801db21fde0
 ffff8801db21f4d8 ffffffff84217840 ffff8800b9463000 ffff8801d7a07860
Call Trace:
 [<ffffffff8376582a>] schedule+0x7a/0x1b0 kernel/sched/core.c:3353
 [<ffffffff83770b40>] schedule_timeout+0x3a0/0x970 kernel/time/timer.c:1515
 [<ffffffff837637be>] io_schedule_timeout+0x1be/0x390 kernel/sched/core.c:4935
 [<ffffffff83766aeb>] io_schedule include/linux/sched.h:447 [inline]
 [<ffffffff83766aeb>] bit_wait_io+0x1b/0xc0 kernel/sched/wait.c:595
 [<ffffffff8376662f>] __wait_on_bit_lock+0x8f/0x140 kernel/sched/wait.c:434
 [<ffffffff8141ddad>] __lock_page+0x18d/0x1f0 mm/filemap.c:888
 [<ffffffff8143cedd>] lock_page include/linux/pagemap.h:458 [inline]
 [<ffffffff8143cedd>] write_cache_pages+0x73d/0xf70 mm/page-writeback.c:2217
 [<ffffffff8143d7ea>] generic_writepages+0xda/0x150 mm/page-writeback.c:2336
 [<ffffffff8144334d>] do_writepages+0xed/0x1c0 mm/page-writeback.c:2350
 [<ffffffff814235e3>] __filemap_fdatawrite_range+0x1b3/0x250 mm/filemap.c:347
 [<ffffffff81423899>] filemap_write_and_wait_range+0x59/0xb0 mm/filemap.c:535
 [<ffffffff815d0286>] blkdev_fsync+0x66/0xb0 fs/block_dev.c:355
 [<ffffffff815bd30a>] vfs_fsync_range+0x10a/0x250 fs/sync.c:195
 [<ffffffff815d19a8>] generic_write_sync include/linux/fs.h:2497 [inline]
 [<ffffffff815d19a8>] blkdev_write_iter+0x398/0x490 fs/block_dev.c:1658
 [<ffffffff8151cd27>] vfs_iter_write+0x1c7/0x2d0 fs/read_write.c:364
 [<ffffffff815b862a>] iter_file_splice_write+0x58a/0xae0 fs/splice.c:1024
 [<ffffffff815b5005>] do_splice_from fs/splice.c:1128 [inline]
 [<ffffffff815b5005>] direct_splice_actor+0x125/0x180 fs/splice.c:1294
 [<ffffffff815b6312>] splice_direct_to_actor+0x2d2/0x830 fs/splice.c:1247
 [<ffffffff815b6a17>] do_splice_direct+0x1a7/0x270 fs/splice.c:1337
 [<ffffffff81520e5c>] do_sendfile+0x54c/0xd30 fs/read_write.c:1227
 [<ffffffff81522eb3>] SYSC_sendfile64 fs/read_write.c:1282 [inline]
 [<ffffffff81522eb3>] SyS_sendfile64+0xc3/0x150 fs/read_write.c:1274
 [<ffffffff8377395f>] entry_SYSCALL_64_fastpath+0x1c/0x98
no locks held by syz-executor1/14324.
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.120-gd63fdf6 #28
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffffffff84217840 task.stack: ffffffff84200000
RIP: 0010:[<ffffffff8129137f>]  [<ffffffff8129137f>] rcu_eqs_exit kernel/rcu/tree.c:824 [inline]
RIP: 0010:[<ffffffff8129137f>]  [<ffffffff8129137f>] rcu_idle_exit+0x6f/0x100 kernel/rcu/tree.c:850
RSP: 0018:ffffffff84207e08  EFLAGS: 00000046
RAX: dffffc0000000000 RBX: ffff8801db218570 RCX: 1ffffffff08fd730
RDX: 1ffff1003b6430ae RSI: ffffffff839fe520 RDI: ffffffff847eb980
RBP: ffffffff84207e20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000292
R13: fffffbfff070889c R14: ffffffff847ebf78 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c420009e80 CR3: 00000000aff82000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff84207e20 dffffc0000000000 ffffffff847ddc08 ffffffff84207ed0
 ffffffff812217d0 fffffbfff08fd7fe ffffffff83772f3a 0000000000000000
 0000000041b58ab3 ffffffff83fa1c6b ffffffff81221570 ffff8801db21f4d8
Call Trace:
 [<ffffffff812217d0>] cpu_idle_poll kernel/sched/idle.c:67 [inline]
 [<ffffffff812217d0>] cpu_idle_loop kernel/sched/idle.c:251 [inline]
 [<ffffffff812217d0>] cpu_startup_entry+0x260/0x8f0 kernel/sched/idle.c:301
 [<ffffffff837608b9>] rest_init+0x189/0x190 init/main.c:410
 [<ffffffff84822811>] start_kernel+0x6b9/0x6ee init/main.c:682
 [<ffffffff84821312>] x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:196
 [<ffffffff84821454>] x86_64_start_kernel+0x140/0x163 arch/x86/kernel/head64.c:185
Code: 48 c1 e9 03 80 3c 11 00 0f 85 98 00 00 00 48 03 1c c5 80 b9 7e 84 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 80 3c 02 00 <75> 6f 48 ba 00 00 00 00 00 00 00 7f 48 8b 03 48 85 d0 74 49 48 
NMI backtrace for cpu 1
CPU: 1 PID: 485 Comm: khungtaskd Not tainted 4.4.120-gd63fdf6 #28
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800bac4b000 task.stack: ffff8800bac88000
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:ffff8800bac8fcb8  EFLAGS: 00000046
RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300
RBP: ffff8800bac8fce0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000246
R13: 0000000000000003 R14: ffffffff8426f420 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f762338b9b8 CR3: 00000000aff82000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff8426f420 ffffffff847efb00 fffffbfff08fda14 dffffc0000000000
 ffff8801db31bca0 ffff8800bac8fd00 ffffffff810b999b ffffffff839f63c0
 0000000000000003 ffff8800bac8fd60 ffffffff81d0eff4 0000000000000000
Call Trace:
 [<ffffffff810b999b>] nmi_raise_cpu_backtrace+0x5b/0x70 arch/x86/kernel/apic/hw_nmi.c:33
 [<ffffffff81d0eff4>] 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
 [<ffffffff81368c9a>] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline]
 [<ffffffff81368c9a>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81368c9a>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81368c9a>] watchdog+0x6fa/0xae0 kernel/hung_task.c:238
 [<ffffffff81190788>] kthread+0x268/0x300 kernel/kthread.c:211
 [<ffffffff83773d85>] 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