buffer_io_error: 4 callbacks suppressed Buffer I/O error on dev loop0, logical block 3, async page read Buffer I/O error on dev loop0, logical block 3, async page read INFO: task syz-executor4:21641 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-executor4 D ffff8801c210f9c0 29080 21641 3853 0x00000004 ffff8801c210f9c0 ffff8801d92db8d0 0000000000000024 ffff8801d92db000 ffffffff842bdbe0 0000000000000000 ffff8801db21fdb8 ffff8801db21fde0 ffff8801db21f4d8 ffff8801c2151800 ffff8801d92db000 0000000000000000 Call Trace: [] schedule+0x7a/0x1b0 kernel/sched/core.c:3353 [] schedule_timeout+0x3a0/0x970 kernel/time/timer.c:1515 [] io_schedule_timeout+0x1be/0x390 kernel/sched/core.c:4935 [] 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 [] vfs_fsync fs/sync.c:209 [inline] [] do_fsync+0x42/0xb0 fs/sync.c:219 [] SYSC_fsync fs/sync.c:228 [inline] [] SyS_fsync+0x16/0x20 fs/sync.c:226 [] entry_SYSCALL_64_fastpath+0x1c/0x98 no locks held by syz-executor4/21641. Sending NMI to all CPUs: NMI backtrace for cpu 0 CPU: 0 PID: 3631 Comm: rs:main Q:Reg Not tainted 4.4.120-gd63fdf6 #28 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801c7799800 task.stack: ffff8801cbb00000 RIP: 0010:[] [] __kernel_text_address+0x21/0xa0 kernel/extable.c:100 RSP: 0018:ffff8801cbb073e8 EFLAGS: 00000297 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000002 RSI: ffffffff8152663a RDI: ffff8800b098e400 RBP: ffff8801cbb073f0 R08: ffff8801cbb074f8 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801cbb07e48 R13: ffffffffffff8000 R14: ffff8801cbb07e28 R15: ffff8800b098e400 FS: 00007ff67529b700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f55fb7e4000 CR3: 00000001c8050000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: 0000000000000000 ffff8801cbb07448 ffffffff810179b8 ffff8801cbb00000 ffff8801cbb07e48 ffff8801cbb074f8 ffffffff83810aa0 0000000000000000 ffffffff83810aa0 00000000000166a0 ffff8801cbb074f8 ffff8801cbb07498 Call Trace: [] print_context_stack+0x48/0xc0 arch/x86/kernel/dumpstack.c:107 [] dump_trace+0x145/0x350 arch/x86/kernel/dumpstack_64.c:243 [] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [] save_stack+0x43/0xd0 mm/kasan/kasan.c:512 [] set_track mm/kasan/kasan.c:524 [inline] [] kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:589 [] slab_free_hook mm/slub.c:1383 [inline] [] slab_free_freelist_hook mm/slub.c:1405 [inline] [] slab_free mm/slub.c:2859 [inline] [] kmem_cache_free+0xc7/0x320 mm/slub.c:2881 [] jbd2_free_handle include/linux/jbd2.h:1302 [inline] [] jbd2_journal_stop+0x34c/0x1410 fs/jbd2/transaction.c:1776 [] __ext4_journal_stop+0x12c/0x1c0 fs/ext4/ext4_jbd2.c:98 [] ext4_da_write_end+0x280/0xd90 fs/ext4/inode.c:2937 [] generic_perform_write+0x338/0x530 mm/filemap.c:2561 [] __generic_file_write_iter+0x35a/0x580 mm/filemap.c:2675 [] ext4_file_write_iter+0x307/0xcc0 fs/ext4/file.c:171 [] new_sync_write fs/read_write.c:478 [inline] [] __vfs_write+0x33c/0x450 fs/read_write.c:491 [] [] 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:ffff8800bad17cb8 EFLAGS: 00000046 RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000 RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300 RBP: ffff8800bad17ce0 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: 00000000021c4000 CR3: 00000001c8050000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffffffff8426f420 ffffffff847efb00 fffffbfff08fda14 dffffc0000000000 ffff8801db31bca0 ffff8800bad17d00 ffffffff810b999b ffffffff839f63c0 0000000000000003 ffff8800bad17d60 ffffffff81d0eff4 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: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