Buffer I/O error on dev loop0, logical block 3, lost async page write INFO: task syz-executor1:29877 blocked for more than 120 seconds. Not tainted 4.4.124-g851fb4d #60 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D ffff8801d7bcf2c0 26568 29877 29711 0x00000004 ffff8801d7bcf2c0 ffff8800bacc68e0 0000000000000025 ffff8800bacc6000 ffffffff842bdb00 ffff8801db21fdb8 ffff8801db21fde0 ffff8801db21f4d8 ffff8801db21f4c0 ffffffff84217840 ffff8800bacc6000 ffff8801d7bcf860 Call Trace: [] schedule+0x7a/0x1b0 kernel/sched/core.c:3359 [] schedule_timeout+0x3a0/0x970 kernel/time/timer.c:1515 [] io_schedule_timeout+0x1be/0x390 kernel/sched/core.c:4941 [] io_schedule include/linux/sched.h:447 [inline] [] bit_wait_io+0x1b/0xc0 kernel/sched/wait.c:595 [] __wait_on_bit+0x8c/0x140 kernel/sched/wait.c:395 [] wait_on_page_bit+0x1e5/0x210 mm/filemap.c:758 [] wait_on_page_writeback include/linux/pagemap.h:530 [inline] [] __filemap_fdatawait_range+0x1c3/0x2e0 mm/filemap.c:410 [] filemap_fdatawait_range+0x25/0x50 mm/filemap.c:440 [] filemap_write_and_wait_range+0x74/0xb0 mm/filemap.c:539 [] blkdev_fsync+0x66/0xb0 fs/block_dev.c:355 [] vfs_fsync_range+0x10a/0x250 fs/sync.c:195 [] generic_write_sync include/linux/fs.h:2498 [inline] [] blkdev_write_iter+0x398/0x490 fs/block_dev.c:1658 [] vfs_iter_write+0x1c7/0x2d0 fs/read_write.c:364 [] iter_file_splice_write+0x58a/0xae0 fs/splice.c:1024 [] do_splice_from fs/splice.c:1128 [inline] [] direct_splice_actor+0x125/0x180 fs/splice.c:1294 [] splice_direct_to_actor+0x2d2/0x830 fs/splice.c:1247 [] do_splice_direct+0x1a7/0x270 fs/splice.c:1337 [] do_sendfile+0x54c/0xd30 fs/read_write.c:1227 [] SYSC_sendfile64 fs/read_write.c:1282 [inline] [] SyS_sendfile64+0xc3/0x150 fs/read_write.c:1274 [] entry_SYSCALL_64_fastpath+0x22/0x9e no locks held by syz-executor1/29877. Sending NMI to all CPUs: NMI backtrace for cpu 0 CPU: 0 PID: 486 Comm: khungtaskd Not tainted 4.4.124-g851fb4d #60 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8800bbb8e000 task.stack: ffff8800bacc8000 RIP: 0010:[] [] native_apic_mem_write arch/x86/include/asm/apic.h:94 [inline] RIP: 0010:[] [] __default_send_IPI_dest_field arch/x86/include/asm/ipi.h:119 [inline] RIP: 0010:[] [] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:61 [inline] RIP: 0010:[] [] flat_send_IPI_mask+0xf7/0x1a0 arch/x86/kernel/apic/apic_flat_64.c:69 RSP: 0018:ffff8800baccfcb8 EFLAGS: 00000046 RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000 RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300 RBP: ffff8800baccfce0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000246 R13: 0000000000000003 R14: ffffffff8426f5a0 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c421d09010 CR3: 00000000ae540000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffffffff8426f5a0 ffffffff847f09c0 fffffbfff08fdbec dffffc0000000000 ffff8801db31bca0 ffff8800baccfd00 ffffffff810b9adb ffffffff839f6e40 0000000000000003 ffff8800baccfd60 ffffffff81d115a4 0000000000000000 Call Trace: [] nmi_raise_cpu_backtrace+0x5b/0x70 arch/x86/kernel/apic/hw_nmi.c:33 [] nmi_trigger_all_cpu_backtrace+0x4a4/0x550 lib/nmi_backtrace.c:85 [] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 [] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline] [] check_hung_task kernel/hung_task.c:125 [inline] [] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline] [] watchdog+0x6fa/0xae0 kernel/hung_task.c:238 [] kthread+0x268/0x300 kernel/kthread.c:211 [] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:510 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 8b 31 17 00 4c 89 e7 57 9d 0f 1f NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.4.124-g851fb4d #60 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801d9b49800 task.stack: ffff8801d9b58000 RIP: 0010:[] [] variable_test_bit arch/x86/include/asm/bitops.h:318 [inline] RIP: 0010:[] [] cpumask_test_cpu include/linux/cpumask.h:294 [inline] RIP: 0010:[] [] switch_mm_irqs_off+0x2a6/0xc30 arch/x86/mm/tlb.c:169 RSP: 0018:ffff8801d9b5fd00 EFLAGS: 00000047 RAX: 0000000000000001 RBX: ffff8801c689c000 RCX: ffffffff81d663fb RDX: ffff8801c689c000 RSI: ffffffff839ff020 RDI: ffffffff839ff060 RBP: ffff8801d9b5fd40 R08: ffffffff83844600 R09: 0000000000000001 R10: dffffc0000000000 R11: 1ffff1003b36bf72 R12: ffff8801c689c000 R13: ffff8801c689c000 R14: ffff8801d9b49ca0 R15: ffffffff847ece38 FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000001190000 CR3: 00000000ae540000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffff8801db31f4d8 ffff8801db31fde8 ffffffff847ece38 ffff8801db31f4c0 ffff8801c689c000 ffff8801c689c000 ffff8801d9b49ca0 ffffffff847ece38 ffff8801d9b5fdc8 ffffffff8376a1d8 0000008bfe9e7fc4 ffff8801d9b5fda0 Call Trace: [] context_switch kernel/sched/core.c:2792 [inline] [] __schedule+0xbd8/0x1da0 kernel/sched/core.c:3330 [] schedule+0x7a/0x1b0 kernel/sched/core.c:3359 [] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3392 [] cpu_idle_loop kernel/sched/idle.c:279 [inline] [] cpu_startup_entry+0x2c0/0x8f0 kernel/sched/idle.c:301 [] start_secondary+0x304/0x3e0 arch/x86/kernel/smpboot.c:242 Code: e9 0a ff ff ff 65 c7 05 0d 1e f3 7e 01 00 00 00 65 48 8b 15 fd 1d f3 7e 49 39 d4 0f 85 5f 05 00 00 89 c0 48 0f a3 83 60 03 00 00 <19> d2 85 d2 0f 85 34 ff ff ff f0 48 0f ab 83 60 03 00 00 48 8d