buffer_io_error: 6 callbacks suppressed
Buffer I/O error on dev loop0, logical block 33008, async page read
Buffer I/O error on dev loop0, logical block 33008, async page read
Buffer I/O error on dev loop0, logical block 33008, async page read
INFO: task syz-executor2:14962 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-executor2   D ffff8800b62f75d0 29008 14962   3920 0x20020004
 ffff8800b62f75d0 ffff8800b5da88d8 00000001814c6848 ffff8800b5da88e0
 0000000000000200 ffff8801db21fdb8 ffff8801db21fde0 ffff8801db21f4d8
 ffff8801db21f4c0 ffff8800b696c800 ffff8800b5da8000 ffff8800b62f7bd0
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
 [<ffffffff838b1502>] __wait_on_bit_lock.part.4+0x92/0x140 kernel/sched/wait.c:434
 [<ffffffff838b15b9>] __wait_on_bit_lock+0x9/0x10 kernel/sched/wait.c:427
 [<ffffffff8141cb2d>] __lock_page+0x17d/0x1f0 mm/filemap.c:888
 [<ffffffff8141fc5c>] lock_page include/linux/pagemap.h:458 [inline]
 [<ffffffff8141fc5c>] pagecache_get_page+0x31c/0x400 mm/filemap.c:1161
 [<ffffffff81420143>] grab_cache_page_write_begin+0x63/0x90 mm/filemap.c:2494
 [<ffffffff815cad3a>] block_write_begin+0x3a/0xd0 fs/buffer.c:2038
 [<ffffffff815d088c>] blkdev_write_begin+0x3c/0x50 fs/block_dev.c:316
 [<ffffffff8141d49f>] generic_perform_write+0x32f/0x540 mm/filemap.c:2550
 [<ffffffff81424152>] __generic_file_write_iter+0x362/0x550 mm/filemap.c:2675
 [<ffffffff815d2fb8>] blkdev_write_iter+0x1c8/0x470 fs/block_dev.c:1655
 [<ffffffff8151c49d>] new_sync_write fs/read_write.c:478 [inline]
 [<ffffffff8151c49d>] __vfs_write+0x30d/0x3f0 fs/read_write.c:491
 [<ffffffff8151e081>] vfs_write+0x191/0x4e0 fs/read_write.c:538
 [<ffffffff81520689>] SYSC_write fs/read_write.c:585 [inline]
 [<ffffffff81520689>] SyS_write+0xd9/0x1c0 fs/read_write.c:577
 [<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
no locks held by syz-executor2/14962.
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 491 Comm: khungtaskd Not tainted 4.4.128-gbd23e3a #19
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d8d81800 task.stack: ffff8801d8d70000
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:ffff8801d8d77cc8  EFLAGS: 00000046
RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300
RBP: ffff8801d8d77cf0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000246
R13: 0000000000000003 R14: 0000000000000002 R15: ffffffff8446f7a0
FS:  0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fda57cef140 CR3: 00000000aca00000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff8446f7a0 ffffffff84a187a0 0000000000000007 fffffbfff0942ba4
 0000000000000040 ffff8801d8d77d10 ffffffff810b5d21 ffffffff83c0b0e0
 0000000000000003 ffff8801d8d77d68 ffffffff81e18b43 ffff8800b5da8000
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 
NMI backtrace for cpu 1
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.4.128-gbd23e3a #19
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d9b49800 task.stack: ffff8801d9b58000
RIP: 0010:[<ffffffff838c0bd0>]  [<ffffffff838c0bd0>] reschedule_interrupt+0x0/0xb0 arch/x86/entry/entry_64.S:763
RSP: 0018:ffff8801d9b5fd78  EFLAGS: 00000046
RAX: 0000000000000007 RBX: ffffffff84a05868 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8801d9b4a0dc
RBP: ffff8801d9b5fda0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000001 R14: fffffbfff074890c R15: ffffffff84a05868
FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000135f3e8 CR3: 00000000aca00000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff810cc306 0000000000000010 0000000000000246 ffff8801d9b5fda0
 0000000000000018 ffff8801d9b5fdd8 ffffffff81025da5 ffff8801d9b60000
 0000000000000000 0000000000000000 fffffbfff074890c ffffffff84a05868
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
 [<ffffffff810aa174>] start_secondary+0x324/0x400 arch/x86/kernel/smpboot.c:242
Code: 04 25 94 66 01 00 65 48 0f 44 24 25 98 66 01 00 57 e8 5e 24 74 fd e8 00 73 7e fd e9 1b e7 ff ff 90 66 2e 0f 1f 84 00 00 00 00 00 <0f> 1f 00 68 02 ff ff ff fc 48 83 c4 88 4c 89 5c 24 30 4c 89 54