buffer_io_error: 7 callbacks suppressed
Buffer I/O error on dev loop0, logical block 0, async page read
INFO: task syz-executor1:9046 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 ffff8800ba87f550 28808  9046   3800 0x00000004
 ffff8800ba87f550 000000000006d9c0 0000000041b58ab3 ffffffff83fb2270
 ffffffff81237410 ffffffff83fb2200 ffff8801db31fdb8 ffff8801db31fde0
 ffff8801db31f4d8 ffff8801cc079800 ffff8801d894b000 ffff8800ba87fb40
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
 [<ffffffff81421356>] lock_page include/linux/pagemap.h:458 [inline]
 [<ffffffff81421356>] pagecache_get_page+0x316/0x3f0 mm/filemap.c:1161
 [<ffffffff81421813>] grab_cache_page_write_begin+0x63/0x90 mm/filemap.c:2494
 [<ffffffff815cb78a>] block_write_begin+0x3a/0xd0 fs/buffer.c:2038
 [<ffffffff815d0d6c>] blkdev_write_begin+0x3c/0x50 fs/block_dev.c:316
 [<ffffffff8141ed1a>] generic_perform_write+0x28a/0x530 mm/filemap.c:2550
 [<ffffffff8142529a>] __generic_file_write_iter+0x35a/0x580 mm/filemap.c:2675
 [<ffffffff815d17e4>] blkdev_write_iter+0x1d4/0x490 fs/block_dev.c:1655
 [<ffffffff8151e0b8>] do_iter_readv_writev+0x138/0x1e0 fs/read_write.c:664
 [<ffffffff8151f852>] do_readv_writev+0x2d2/0x6e0 fs/read_write.c:808
 [<ffffffff8151fd8b>] vfs_writev+0x7b/0xb0 fs/read_write.c:847
 [<ffffffff81522779>] SYSC_pwritev fs/read_write.c:936 [inline]
 [<ffffffff81522779>] SyS_pwritev+0x199/0x230 fs/read_write.c:922
 [<ffffffff8377395f>] entry_SYSCALL_64_fastpath+0x1c/0x98
no locks held by syz-executor1/9046.
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 486 Comm: khungtaskd Not tainted 4.4.120-gd63fdf6 #28
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800bac54800 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: 000000c420265010 CR3: 00000000bbbda000 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 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 
NMI backtrace for cpu 1
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.4.120-gd63fdf6 #28
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d9b49800 task.stack: ffff8801d9b58000
RIP: 0010:[<ffffffff811d40a0>]  [<ffffffff811d40a0>] sched_clock_tick+0x0/0x120 kernel/sched/clock.c:392
RSP: 0018:ffff8801d9b5fd98  EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff8801db319c40 RCX: ffffffff812d5196
RDX: 0000000000000000 RSI: ffff8801db319c40 RDI: ffffffff847ec054
RBP: ffff8801d9b5fda0 R08: ffff88021fffd058 R09: 0000000000000006
R10: ffffed0043fffa09 R11: 0000000000000000 R12: 00000054207d96da
R13: ffff8801db319cd0 R14: 00000054207d96da R15: ffff8801d9b60000
FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000001474000 CR3: 00000001d213a000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff811d4202 ffff8801d9b5fdc0 ffffffff812d56fb ffff8801db319c40
 ffff8801db319cb4 ffff8801d9b5fdf8 ffffffff812d78ff ffff8801d9b5fde8
 dffffc0000000000 ffffffff847ddc08 fffffbfff070889c ffffffff847ebf78
Call Trace:
 [<ffffffff812d56fb>] tick_nohz_stop_idle+0x5b/0x70 kernel/time/tick-sched.c:463
 [<ffffffff812d78ff>] tick_nohz_idle_exit+0x2cf/0x3d0 kernel/time/tick-sched.c:943
 [<ffffffff81221815>] cpu_idle_loop kernel/sched/idle.c:267 [inline]
 [<ffffffff81221815>] cpu_startup_entry+0x2a5/0x8f0 kernel/sched/idle.c:301
 [<ffffffff810adc64>] start_secondary+0x304/0x3e0 arch/x86/kernel/smpboot.c:242
Code: 03 55 48 89 e5 85 c0 7f 0e 65 8b 3d 93 20 e4 7e e8 c6 fd ff ff 5d c3 e8 5f 20 e5 ff 5d c3 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 <8b> 05 5a e1 84 03 85 c0 0f 8f b9 00 00 00 8b 05 18 7f 61 03 85