netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. buffer_io_error: 40 callbacks suppressed Buffer I/O error on dev loop0, logical block 16, async page read INFO: task blkid:12020 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. blkid D ffff8801d43cf878 27896 12020 2324 0x00000006 ffff8801d43cf878 ffff8801d498b000 0000000000000000 0000000000000007 ffff8801d498b000 ffff8801db31fdb8 ffff8801db31fde0 ffff8801db31f4d8 ffff8801db31f4c0 ffff8801d9b49800 ffff8801d498b000 0000000000000000 Call Trace: [] schedule+0x7a/0x1b0 kernel/sched/core.c:3359 [] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3392 [] __mutex_lock_common kernel/locking/mutex.c:582 [inline] [] mutex_lock_nested+0x306/0x850 kernel/locking/mutex.c:621 [] blkdev_put+0x2a/0x550 fs/block_dev.c:1558 [] blkdev_close+0x8b/0xb0 fs/block_dev.c:1607 [] __fput+0x233/0x6d0 fs/file_table.c:208 [] ____fput+0x15/0x20 fs/file_table.c:244 [] task_work_run+0x104/0x180 kernel/task_work.c:115 [] exit_task_work include/linux/task_work.h:21 [inline] [] do_exit+0x82a/0x2a10 kernel/exit.c:759 [] do_group_exit+0x108/0x320 kernel/exit.c:889 [] get_signal+0x4f2/0x1550 kernel/signal.c:2317 [] do_signal+0x8b/0x1d40 arch/x86/kernel/signal.c:712 [] exit_to_usermode_loop+0x11a/0x160 arch/x86/entry/common.c:248 [] prepare_exit_to_usermode arch/x86/entry/common.c:283 [inline] [] syscall_return_slowpath+0x1b5/0x1f0 arch/x86/entry/common.c:348 [] int_ret_from_sys_call+0x25/0xa3 1 lock held by blkid/12020: #0: (&bdev->bd_mutex){+.+.+.}, at: [] blkdev_put+0x2a/0x550 fs/block_dev.c:1558 Sending NMI to all CPUs: NMI backtrace for cpu 0 CPU: 0 PID: 486 Comm: khungtaskd Not tainted 4.4.125-g38f41ec #21 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8800bade1800 task.stack: ffff8800bb0c8000 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:ffff8800bb0cfcb8 EFLAGS: 00000046 RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000 RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300 RBP: ffff8800bb0cfce0 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: 00007fb1acc07000 CR3: 00000000b4802000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffffffff8426f5a0 ffffffff847f0b40 fffffbfff08fdc1c dffffc0000000000 ffff8801db31bca0 ffff8800bb0cfd00 ffffffff810b9abb ffffffff839f6dc0 0000000000000003 ffff8800bb0cfd60 ffffffff81d11764 ffffffff8141b993 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: 0 Comm: swapper/1 Not tainted 4.4.125-g38f41ec #21 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801d9b49800 task.stack: ffff8801d9b58000 RIP: 0010:[] [] __trace_hardirqs_on_caller kernel/locking/lockdep.c:2568 [inline] RIP: 0010:[] [] trace_hardirqs_on_caller+0x2bc/0x590 kernel/locking/lockdep.c:2612 RSP: 0018:ffff8801d9b5fdb0 EFLAGS: 00000806 RAX: dffffc0000000000 RBX: ffff8801d9b49800 RCX: 0000000000000000 RDX: 1ffff1003b369412 RSI: 0000000000000001 RDI: ffff8801d9b4a090 RBP: ffff8801d9b5fdc0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff81291931 R13: fffffbfff07088c0 R14: ffffffff847ecfb8 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000081186f4 CR3: 00000000b4802000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffff8801db318570 0000000000000282 ffff8801d9b5fdd0 ffffffff812372cd ffff8801d9b5fdf8 ffffffff81291931 ffff8801d9b5fdf8 dffffc0000000000 ffffffff847dec48 ffff8801d9b5fea8 ffffffff81221cb0 fffffbfff08fda06 Call Trace: [] trace_hardirqs_on+0xd/0x10 kernel/locking/lockdep.c:2619 [] rcu_idle_exit+0xa1/0x100 kernel/rcu/tree.c:852 [] cpu_idle_poll kernel/sched/idle.c:67 [inline] [] cpu_idle_loop kernel/sched/idle.c:251 [inline] [] cpu_startup_entry+0x260/0x8f0 kernel/sched/idle.c:301 [] start_secondary+0x304/0x3e0 arch/x86/kernel/smpboot.c:242 Code: 8e d5 01 00 00 8b 83 c8 08 00 00 85 c0 0f 85 da 00 00 00 48 8d bb 90 08 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 a8 02 00 00 48 8d bb 88 08 00 00 4c 89 a3 90