Buffer I/O error on dev loop0, logical block 8, lost async page write Buffer I/O error on dev loop0, logical block 9, lost async page write Buffer I/O error on dev loop0, logical block 10, lost async page write buffer_io_error: 5 callbacks suppressed Buffer I/O error on dev loop0, logical block 16, async page read INFO: task syz-executor0:4526 blocked for more than 120 seconds. Not tainted 4.16.0+ #288 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D18912 4526 4517 0x20020000 Call Trace: context_switch kernel/sched/core.c:2848 [inline] __schedule+0x8fb/0x1ef0 kernel/sched/core.c:3490 schedule+0xf5/0x430 kernel/sched/core.c:3549 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3607 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0xb7f/0x1810 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 __blkdev_get+0x176/0x13b0 fs/block_dev.c:1458 blkdev_get+0x399/0xb00 fs/block_dev.c:1609 blkdev_open+0x1c9/0x250 fs/block_dev.c:1767 do_dentry_open+0x772/0xd70 fs/open.c:794 vfs_open+0x107/0x220 fs/open.c:908 do_last fs/namei.c:3379 [inline] path_openat+0x1151/0x3590 fs/namei.c:3519 do_filp_open+0x25b/0x3b0 fs/namei.c:3554 do_sys_open+0x502/0x6d0 fs/open.c:1101 C_SYSC_open fs/open.c:1138 [inline] compat_SyS_open+0x2a/0x40 fs/open.c:1136 do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] do_fast_syscall_32+0x3ec/0xf9f arch/x86/entry/common.c:392 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7ff1c99 RSP: 002b:000000000844eac8 EFLAGS: 00000246 ORIG_RAX: 0000000000000005 RAX: ffffffffffffffda RBX: 000000000844f88c RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000013 RDI: 000000000844f7ac RBP: 000000000000058f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by khungtaskd/877: #0: 0000000081fae67d (rcu_read_lock){....}, at: check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: 0000000081fae67d (rcu_read_lock){....}, at: watchdog+0x1d6/0xd70 kernel/hung_task.c:249 #1: 00000000000d3f4e (tasklist_lock){.+.+}, at: debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 1 lock held by rsyslogd/4360: #0: 0000000071cb7687 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x165/0x1a0 fs/file.c:766 2 locks held by getty/4450: #0: 0000000044766bb5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000045128baf (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4451: #0: 000000005d7de8bc (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000004833320e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4452: #0: 00000000b4e151db (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000239d6125 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4453: #0: 00000000c875ad64 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000002a7c760a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4454: #0: 00000000a090b137 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000000db1714f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4455: #0: 00000000ec12c429 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000f0c77a99 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4456: #0: 000000005d17eb94 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000a0e341ae (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 1 lock held by syz-executor0/4526: #0: 00000000ea4b9be6 (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x176/0x13b0 fs/block_dev.c:1458 3 locks held by kworker/u4:4/21719: #0: 00000000d9e47364 ((wq_completion)"writeback"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 00000000d9e47364 ((wq_completion)"writeback"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000d9e47364 ((wq_completion)"writeback"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000d9e47364 ((wq_completion)"writeback"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:57 [inline] #0: 00000000d9e47364 ((wq_completion)"writeback"){+.+.}, at: set_work_data kernel/workqueue.c:619 [inline] #0: 00000000d9e47364 ((wq_completion)"writeback"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: 00000000d9e47364 ((wq_completion)"writeback"){+.+.}, at: process_one_work+0xb83/0x1c40 kernel/workqueue.c:2084 #1: 00000000a0f866a8 ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0xbd9/0x1c40 kernel/workqueue.c:2088 #2: 00000000926a7c88 (&type->s_umount_key#35){++++}, at: trylock_super+0x20/0x100 fs/super.c:395 1 lock held by syz-executor7/26613: #0: 00000000ea4b9be6 (&bdev->bd_mutex){+.+.}, at: iterate_bdevs+0xc8/0x260 fs/block_dev.c:2160 1 lock held by syz-executor7/26649: #0: 00000000ea4b9be6 (&bdev->bd_mutex){+.+.}, at: iterate_bdevs+0xc8/0x260 fs/block_dev.c:2160 1 lock held by blkid/26614: #0: 00000000ea4b9be6 (&bdev->bd_mutex){+.+.}, at: blkdev_put+0x2a/0x4f0 fs/block_dev.c:1808 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 877 Comm: khungtaskd Not tainted 4.16.0+ #288 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1a7/0x27d lib/dump_stack.c:53 nmi_cpu_backtrace+0x1e0/0x220 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x123/0x180 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline] check_hung_task kernel/hung_task.c:132 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline] watchdog+0x969/0xd70 kernel/hung_task.c:249 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:411 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.16.0+ #288 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__read_once_size include/linux/compiler.h:188 [inline] RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:2314 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:2334 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:2388 [inline] RIP: 0010:__lock_acquire+0x1260/0x3c30 kernel/locking/lockdep.c:3431 RSP: 0018:ffff8801db0072d0 EFLAGS: 00000046 RAX: ffff8801db007420 RBX: ffffffff88475a78 RCX: 0000000083828056 RDX: dffffc0000000000 RSI: 0000000080a8074e RDI: 0000000000000000 RBP: ffff8801db007670 R08: 0000000000000000 R09: 000000000000000c R10: 0000000000000001 R11: fffffbfff13274d3 R12: 000000000000266c R13: 6c26e8a901bc65a0 R14: ffffffff88475200 R15: ffffffff8934c068 FS: 0000000000000000(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001b09c1000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920 call_timer_fn+0x1f0/0x820 kernel/time/timer.c:1323 expire_timers kernel/time/timer.c:1359 [inline] __run_timers+0x6d4/0xb70 kernel/time/timer.c:1666 run_timer_softirq+0x60/0x70 kernel/time/timer.c:1694 __do_softirq+0x2d7/0xb85 kernel/softirq.c:285 invoke_softirq kernel/softirq.c:365 [inline] irq_exit+0x1cc/0x200 kernel/softirq.c:405 exiting_irq arch/x86/include/asm/apic.h:525 [inline] smp_apic_timer_interrupt+0x16b/0x700 arch/x86/kernel/apic/apic.c:1052 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:862 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54 RSP: 0018:ffffffff88407c38 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff12 RAX: dffffc0000000000 RBX: 1ffffffff1080f8a RCX: 0000000000000000 RDX: 1ffffffff10a2558 RSI: 0000000000000001 RDI: ffffffff88512ac0 RBP: ffffffff88407c38 R08: ffffed003b6046c3 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff88407cf0 R14: ffffffff88eccfa0 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0xbf/0x430 arch/x86/kernel/process.c:354 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:345 default_idle_call+0x36/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:151 [inline] do_idle+0x24a/0x3b0 kernel/sched/idle.c:241 cpu_startup_entry+0x104/0x120 kernel/sched/idle.c:346 rest_init+0xed/0xf0 init/main.c:437 start_kernel+0x7f1/0x819 init/main.c:717 x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:443 x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:424 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:242 Code: 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 84 26 00 00 48 8d 85 b0 fd ff ff 48 ba 00 00 00 00 00 fc ff df 4e 8b 3c e5 80 43 8c 89 <48> 89 c1 48 c1 e9 03 80 3c 11 00 0f 85 31 26 00 00 48 c1 e8 03