Buffer I/O error on dev loop0, logical block 20, async page read
Buffer I/O error on dev loop0, logical block 21, async page read
Buffer I/O error on dev loop0, logical block 22, async page read
Buffer I/O error on dev loop0, logical block 23, async page read
Buffer I/O error on dev loop0, logical block 24, async page read
INFO: task syz-executor7:31704 blocked for more than 120 seconds.
      Not tainted 4.4.128-gbd23e3a #19
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7   D ffff8800b14ef920 28176 31704   3907 0x20020004
 ffff8800b14ef920 ffff8800af723908 0000000000000025 ffffffff844bdc20
 0000000000000000 ffff8801db31fdb8 ffff8801db31fde0 ffff8801db31f4d8
 ffff8801db31f4c0 ffff8801d9b49800 ffff8800af723000 0000000000000000
Call Trace:
 [<ffffffff838b074a>] schedule+0x7a/0x1b0 kernel/sched/core.c:3359
 [<ffffffff838bbb61>] schedule_timeout+0x481/0x8b0 kernel/time/timer.c:1515
 [<ffffffff838ae60a>] io_schedule_timeout+0x1ba/0x390 kernel/sched/core.c:4941
 [<ffffffff838b199b>] io_schedule include/linux/sched.h:447 [inline]
 [<ffffffff838b199b>] bit_wait_io+0x1b/0xd0 kernel/sched/wait.c:595
 [<ffffffff838b112d>] __wait_on_bit+0xbd/0x140 kernel/sched/wait.c:395
 [<ffffffff8141c247>] wait_on_page_bit+0x1d7/0x200 mm/filemap.c:758
 [<ffffffff8141c433>] wait_on_page_writeback include/linux/pagemap.h:530 [inline]
 [<ffffffff8141c433>] __filemap_fdatawait_range+0x1c3/0x2c0 mm/filemap.c:410
 [<ffffffff81424ab3>] filemap_fdatawait_keep_errors+0x63/0x80 mm/filemap.c:468
 [<ffffffff815bc7a0>] fdatawait_one_bdev+0x50/0x70 fs/sync.c:94
 [<ffffffff815d5fcc>] iterate_bdevs+0x10c/0x260 fs/block_dev.c:1832
 [<ffffffff815bd081>] sys_sync+0xe1/0x170 fs/sync.c:116
 [<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
 [<ffffffff838c00aa>] sysenter_flags_fixed+0xd/0x17
1 lock held by syz-executor7/31704:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff815d5f88>] iterate_bdevs+0xc8/0x260 fs/block_dev.c:1830
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.128-gbd23e3a #19
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffffffff84417840 task.stack: ffffffff84400000
RIP: 0010:[<ffffffff810cc306>]  [<ffffffff810cc306>] native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:49
RSP: 0018:ffffffff84407dc8  EFLAGS: 00000246
RAX: 0000000000000007 RBX: ffffffff84a05868 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff8441811c
RBP: ffffffff84407dc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: fffffbfff074890c R15: ffffffff84a05868
FS:  0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000002556000 CR3: 00000001c8e70000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff84407e00 ffffffff81025da5 ffffffff84408000 0000000000000000
 0000000000000000 fffffbfff074890c ffffffff84a05868 ffffffff84407e10
 ffffffff810272f0 ffffffff84407e28 ffffffff8121b9c7 dffffc0000000000
Call Trace:
 [<ffffffff81025da5>] arch_safe_halt arch/x86/include/asm/paravirt.h:117 [inline]
 [<ffffffff81025da5>] default_idle+0x55/0x3c0 arch/x86/kernel/process.c:290
 [<ffffffff810272f0>] arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:281
 [<ffffffff8121b9c7>] default_idle_call+0x57/0x70 kernel/sched/idle.c:93
 [<ffffffff8121c16f>] cpuidle_idle_call kernel/sched/idle.c:157 [inline]
 [<ffffffff8121c16f>] cpu_idle_loop kernel/sched/idle.c:253 [inline]
 [<ffffffff8121c16f>] cpu_startup_entry+0x6af/0x780 kernel/sched/idle.c:301
 [<ffffffff838ab8b1>] 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: 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: 492 Comm: khungtaskd Not tainted 4.4.128-gbd23e3a #19
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d8f0b000 task.stack: ffff8801d8ed8000
RIP: 0010:[<ffffffff810bfd66>]  [<ffffffff810bfd66>] native_apic_mem_write arch/x86/include/asm/apic.h:94 [inline]
RIP: 0010:[<ffffffff810bfd66>]  [<ffffffff810bfd66>] __default_send_IPI_dest_field arch/x86/include/asm/ipi.h:119 [inline]
RIP: 0010:[<ffffffff810bfd66>]  [<ffffffff810bfd66>] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:61 [inline]
RIP: 0010:[<ffffffff810bfd66>]  [<ffffffff810bfd66>] flat_send_IPI_mask+0xf6/0x1a0 arch/x86/kernel/apic/apic_flat_64.c:69
RSP: 0018:ffff8801d8edfcc8  EFLAGS: 00000046
RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300
RBP: ffff8801d8edfcf0 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: 0000000020000080 CR3: 00000001c8e70000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff8446f7a0 ffffffff84a187a0 0000000000000007 fffffbfff0942ba4
 0000000000000040 ffff8801d8edfd10 ffffffff810b5d21 ffffffff83c0b0e0
 0000000000000003 ffff8801d8edfd68 ffffffff81e18b43 ffffffff8140da9f
Call Trace:
 [<ffffffff810b5d21>] nmi_raise_cpu_backtrace+0x61/0x80 arch/x86/kernel/apic/hw_nmi.c:33
 [<ffffffff81e18b43>] nmi_trigger_all_cpu_backtrace.cold.4+0x70/0xad lib/nmi_backtrace.c:85
 [<ffffffff810b5dc4>] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 [<ffffffff8141a189>] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline]
 [<ffffffff8141a189>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff8141a189>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff8141a189>] watchdog.cold.1+0xd3/0xee kernel/hung_task.c:238
 [<ffffffff81190748>] kthread+0x268/0x300 kernel/kthread.c:211
 [<ffffffff838beb95>] 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 82