Buffer I/O error on dev loop0, logical block 10, lost async page write Buffer I/O error on dev loop0, logical block 11, lost async page write Buffer I/O error on dev loop0, logical block 12, lost async page write buffer_io_error: 2 callbacks suppressed Buffer I/O error on dev loop0, logical block 15, async page read INFO: task syz-executor0:15268 blocked for more than 120 seconds. Not tainted 4.16.0-rc4+ #341 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D23184 15268 6107 0x00000004 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440 schedule+0xf5/0x430 kernel/sched/core.c:3499 io_schedule+0x1c/0x70 kernel/sched/core.c:5115 wait_on_page_bit_common+0x4b3/0x770 mm/filemap.c:1099 wait_on_page_bit mm/filemap.c:1132 [inline] wait_on_page_writeback include/linux/pagemap.h:546 [inline] __filemap_fdatawait_range+0x282/0x430 mm/filemap.c:533 filemap_fdatawait_keep_errors+0x2a/0xb0 mm/filemap.c:600 fdatawait_one_bdev+0x50/0x70 fs/sync.c:95 iterate_bdevs+0x109/0x260 fs/block_dev.c:2162 sys_sync+0x120/0x1c0 fs/sync.c:117 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x453d69 RSP: 002b:00007faa6a4a3c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007faa6a4a46d4 RCX: 0000000000453d69 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000061f R14: 00000000006f9388 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by khungtaskd/799: #0: (rcu_read_lock){....}, at: [<000000008e238433>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<000000008e238433>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<00000000931c420e>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 1 lock held by rsyslogd/4104: #0: (&f->f_pos_lock){+.+.}, at: [<00000000523a6613>] __fdget_pos+0x12b/0x190 fs/file.c:765 2 locks held by getty/4226: #0: (&tty->ldisc_sem){++++}, at: [<00000000541238ef>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000089730099>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4227: #0: (&tty->ldisc_sem){++++}, at: [<00000000541238ef>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000089730099>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4228: #0: (&tty->ldisc_sem){++++}, at: [<00000000541238ef>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000089730099>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4229: #0: (&tty->ldisc_sem){++++}, at: [<00000000541238ef>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000089730099>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4230: #0: (&tty->ldisc_sem){++++}, at: [<00000000541238ef>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000089730099>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4231: #0: (&tty->ldisc_sem){++++}, at: [<00000000541238ef>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000089730099>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4232: #0: (&tty->ldisc_sem){++++}, at: [<00000000541238ef>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000089730099>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 1 lock held by blkid/12258: #0: (&bdev->bd_mutex){+.+.}, at: [<000000003e985e17>] blkdev_put+0x2a/0x4f0 fs/block_dev.c:1808 3 locks held by kworker/u4:8/14540: #0: ((wq_completion)"writeback"){+.+.}, at: [<000000008748fb74>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"writeback"){+.+.}, at: [<000000008748fb74>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"writeback"){+.+.}, at: [<000000008748fb74>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"writeback"){+.+.}, at: [<000000008748fb74>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: [<000000002d1bf9ab>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 #2: (&type->s_umount_key#27){.+.+}, at: [<0000000078fa895c>] trylock_super+0x20/0x100 fs/super.c:395 1 lock held by syz-executor0/15268: #0: (&bdev->bd_mutex){+.+.}, at: [<000000002d550e25>] iterate_bdevs+0xc8/0x260 fs/block_dev.c:2160 1 lock held by syz-executor0/15285: #0: (&bdev->bd_mutex){+.+.}, at: [<000000002d550e25>] iterate_bdevs+0xc8/0x260 fs/block_dev.c:2160 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 799 Comm: khungtaskd Not tainted 4.16.0-rc4+ #341 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+0x194/0x24d lib/dump_stack.c:53 nmi_cpu_backtrace+0x1d2/0x210 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+0x90c/0xd60 kernel/hung_task.c:249 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406 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-rc4+ #341 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:ktime_get+0x7e/0x3a0 kernel/time/timekeeping.c:759 RSP: 0018:ffff8801db207c30 EFLAGS: 00000093 RAX: ffffffff86e2c340 RBX: ffff8801db226620 RCX: ffffffff8161c848 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000086 RBP: ffff8801db207d18 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1003b640f8a R13: ffff8801db207cf0 R14: ffff8801db207e68 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000009d36bc CR3: 0000000006e22003 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: tick_nohz_irq_enter kernel/time/tick-sched.c:1148 [inline] tick_irq_enter+0x9e/0x390 kernel/time/tick-sched.c:1169 irq_enter+0xb6/0xd0 kernel/softirq.c:346 scheduler_ipi+0x23d/0x820 kernel/sched/core.c:1794 smp_reschedule_interrupt+0xe6/0x650 arch/x86/kernel/smp.c:277 reschedule_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:881 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54 RSP: 0018:ffffffff86e07c38 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02 RAX: dffffc0000000000 RBX: 1ffffffff0dc0f8a RCX: 0000000000000000 RDX: 1ffffffff0dd9328 RSI: 0000000000000001 RDI: ffffffff86ec9940 RBP: ffffffff86e07c38 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff86e07cf0 R14: ffffffff876e7620 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:98 cpuidle_idle_call kernel/sched/idle.c:156 [inline] do_idle+0x24a/0x3b0 kernel/sched/idle.c:246 cpu_startup_entry+0x104/0x120 kernel/sched/idle.c:351 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:378 x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:359 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:239 Code: f1 f1 f1 f1 c7 40 04 04 f2 f2 f2 c7 40 08 f2 f2 f2 f2 c7 40 0c 00 f2 f2 f2 c7 40 10 f3 f3 f3 f3 e8 e8 3d 0f 00 8b 15 66 af 0c 06 <85> d2 0f 85 b4 02 00 00 48 c7 c0 30 99 ec 86 48 bb 00 00 00 00