Buffer I/O error on dev loop0, logical block 1, async page read kworker/dying (83) used greatest stack depth: 14272 bytes left Buffer I/O error on dev loop0, logical block 3, async page read INFO: task syz-executor0:4539 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 D21184 4539 4531 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: 0023:0xf7f89c99 RSP: 002b:000000000844eac8 EFLAGS: 00000246 ORIG_RAX: 0000000000000005 RAX: ffffffffffffffda RBX: 000000000844f88c RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000013 RDI: 000000000844f7ac RBP: 000000000000010f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 3 locks held by kworker/u4:2/42: #0: 0000000011f4dbc3 ((wq_completion)"writeback"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 0000000011f4dbc3 ((wq_completion)"writeback"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000011f4dbc3 ((wq_completion)"writeback"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 0000000011f4dbc3 ((wq_completion)"writeback"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:57 [inline] #0: 0000000011f4dbc3 ((wq_completion)"writeback"){+.+.}, at: set_work_data kernel/workqueue.c:619 [inline] #0: 0000000011f4dbc3 ((wq_completion)"writeback"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: 0000000011f4dbc3 ((wq_completion)"writeback"){+.+.}, at: process_one_work+0xb83/0x1c40 kernel/workqueue.c:2084 #1: 000000003d7ba50f ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0xbd9/0x1c40 kernel/workqueue.c:2088 #2: 0000000080ea3411 (&type->s_umount_key#35){.+.+}, at: trylock_super+0x20/0x100 fs/super.c:395 2 locks held by khungtaskd/877: #0: 00000000e426eeff (rcu_read_lock){....}, at: check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: 00000000e426eeff (rcu_read_lock){....}, at: watchdog+0x1d6/0xd70 kernel/hung_task.c:249 #1: 00000000515f39ad (tasklist_lock){.+.+}, at: debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 1 lock held by rsyslogd/4374: #0: 00000000cbf967d1 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x165/0x1a0 fs/file.c:766 2 locks held by getty/4464: #0: 000000002bede7ee (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000b05aa9f4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4465: #0: 00000000b7aad83d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000003b9ea104 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4466: #0: 0000000078759426 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000022f78d14 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4467: #0: 00000000d6f6848a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000002c3164e8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4468: #0: 0000000015c230f9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000093c01a41 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4469: #0: 00000000d89c19c8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000091e3b941 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4470: #0: 0000000010a43540 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000007dd6128c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 1 lock held by syz-executor0/4539: #0: 00000000361930d0 (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x176/0x13b0 fs/block_dev.c:1458 1 lock held by blkid/16225: #0: 00000000361930d0 (&bdev->bd_mutex){+.+.}, at: blkdev_put+0x2a/0x4f0 fs/block_dev.c:1808 1 lock held by syz-executor7/16285: #0: 00000000361930d0 (&bdev->bd_mutex){+.+.}, at: iterate_bdevs+0xc8/0x260 fs/block_dev.c:2160 1 lock held by syz-executor7/16290: #0: 00000000361930d0 (&bdev->bd_mutex){+.+.}, at: iterate_bdevs+0xc8/0x260 fs/block_dev.c:2160 ============================================= 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:__lock_acquire+0x114/0x3c30 kernel/locking/lockdep.c:3290 RSP: 0018:ffff8801db0076c0 EFLAGS: 00000086 RAX: ffffed003b600eee RBX: 0000000000000000 RCX: 0000000000000002 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffffff89df2508 RBP: ffff8801db007a60 R08: 0000000000000001 R09: 0000000000000001 R10: ffff8801db007a80 R11: ffffed003b6046c2 R12: 1ffff1003b600f5a R13: ffffffff89df2508 R14: ffffffff88475200 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001accd0000 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 seqcount_lockdep_reader_access include/linux/seqlock.h:81 [inline] read_seqcount_begin include/linux/seqlock.h:164 [inline] ktime_get+0x12f/0x3a0 kernel/time/timekeeping.c:762 tick_nohz_irq_enter kernel/time/tick-sched.c:1124 [inline] tick_irq_enter+0x9e/0x390 kernel/time/tick-sched.c:1145 irq_enter+0xb6/0xd0 kernel/softirq.c:346 scheduler_ipi+0x317/0xa40 kernel/sched/core.c:1768 smp_reschedule_interrupt+0xe6/0x650 arch/x86/kernel/smp.c:277 reschedule_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:886 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54 RSP: 0018:ffffffff88407c38 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02 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: f2 c7 40 28 f2 f2 f2 f2 c7 40 2c 00 f2 f2 f2 c7 40 30 f2 f2 f2 f2 c7 40 34 00 f2 f2 f2 c7 40 38 f2 f2 f2 f2 c7 40 3c 00 f2 f2 f2 40 40 f2 f2 f2 f2 c7 40 44 00 00 00 f2 c7 40 48 f2 f2 f2 f2