buffer_io_error: 8 callbacks suppressed Buffer I/O error on dev loop0, logical block 16, async page read Buffer I/O error on dev loop0, logical block 16, async page read INFO: task syz-executor3:31010 blocked for more than 120 seconds. Not tainted 4.4.125-g38f41ec #21 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D ffff8801d2517940 29352 31010 3824 0x20020004 ffff8801d2517940 ffff8801d92150e0 0000000000000025 ffff8801d9214800 ffffffff842bdb00 ffff8801db21fdb8 ffff8801db21fde0 ffff8801db21f4d8 ffff8801db21f4c0 ffff8801bb908000 ffff8801d9214800 0000000000000000 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 [] vfs_fsync fs/sync.c:209 [inline] [] do_fsync+0x42/0xb0 fs/sync.c:219 [] SYSC_fdatasync fs/sync.c:233 [inline] [] SyS_fdatasync+0x19/0x20 fs/sync.c:231 [] do_syscall_32_irqs_on arch/x86/entry/common.c:392 [inline] [] do_fast_syscall_32+0x321/0x8a0 arch/x86/entry/common.c:459 [] sysenter_flags_fixed+0xd/0x17 no locks held by syz-executor3/31010. Sending NMI to all CPUs: NMI backtrace for cpu 0 CPU: 0 PID: 487 Comm: khungtaskd Not tainted 4.4.125-g38f41ec #21 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801d8c1b000 task.stack: ffff8800bac30000 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:ffff8800bac37cb8 EFLAGS: 00000046 RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000 RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300 RBP: ffff8800bac37ce0 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: 0000000000775000 CR3: 00000000b4950000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffffffff8426f5a0 ffffffff847f0b40 fffffbfff08fdc1c dffffc0000000000 ffff8801db31bca0 ffff8800bac37d00 ffffffff810b9abb ffffffff839f6dc0 0000000000000003 ffff8800bac37d60 ffffffff81d11764 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 2b 33 17 00 4c 89 e7 57 9d 0f 1f NMI backtrace for cpu 1 CPU: 1 PID: 3635 Comm: rsyslogd Not tainted 4.4.125-g38f41ec #21 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8800b3e88000 task.stack: ffff8800b4b08000 RIP: 0010:[] [] valid_stack_ptr arch/x86/kernel/dumpstack.c:92 [inline] RIP: 0010:[] [] print_context_stack+0x75/0xc0 arch/x86/kernel/dumpstack.c:103 RSP: 0018:ffff8800b4b0f7c0 EFLAGS: 00000246 RAX: ffff8800b4b08000 RBX: 0000000000000000 RCX: ffffffff81035e30 RDX: 0000000000000000 RSI: ffffffff81230631 RDI: ffff8800b4b0f8b8 RBP: ffff8800b4b0f808 R08: ffff8800b4b0f8b8 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8800b4b0fad8 R13: ffffffffffff8000 R14: ffff8800b4b0f920 R15: ffffffff81230631 FS: 00007f519fa9b700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f62dc6d0140 CR3: 00000000b4950000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffff8800b4b08000 ffff8800b4b0fad8 ffff8800b4b0f8b8 ffffffff83810aa0 0000000000000000 ffffffff83810aa0 00000000000166a0 ffff8800b4b0f8b8 ffff8800b4b0f858 ffff8800b4b0f890 ffffffff81016b75 ffff8800b4b0f854 Call Trace: [] 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_kmalloc+0xad/0xe0 mm/kasan/kasan.c:616 [] kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:554 [] slab_post_alloc_hook mm/slub.c:1349 [inline] [] slab_alloc_node mm/slub.c:2615 [inline] [] slab_alloc mm/slub.c:2623 [inline] [] kmem_cache_alloc_trace+0xbe/0x2b0 mm/slub.c:2640 [] kmalloc include/linux/slab.h:476 [inline] [] syslog_print kernel/printk/printk.c:1148 [inline] [] do_syslog+0x60f/0xae0 kernel/printk/printk.c:1331 [] kmsg_read+0x74/0xa0 fs/proc/kmsg.c:39 [] proc_reg_read+0xef/0x170 fs/proc/inode.c:202 [] __vfs_read+0x103/0x440 fs/read_write.c:432 [] vfs_read+0x123/0x3a0 fs/read_write.c:454 [] SYSC_read fs/read_write.c:569 [inline] [] SyS_read+0xd9/0x1b0 fs/read_write.c:562 [] entry_SYSCALL_64_fastpath+0x22/0x9e Code: 74 1c 48 8b 45 d0 48 8b 08 49 8d 44 24 08 49 39 c6 74 2f 31 d2 4c 89 fe 48 8b 7d c8 ff d1 49 83 c6 08 48 85 db 75 c2 48 8b 45 b8 <49> 39 c6 77 30 48 83 c4 20 4c 89 e0 5b 41 5c 41 5d 41 5e 41 5f