Buffer I/O error on dev loop0, logical block 7, async page read INFO: task syz-executor7:11680 blocked for more than 120 seconds. Not tainted 4.15.0-rc6-next-20180105+ #89 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor7 D27408 11680 3695 0x00000004 Call Trace: context_switch kernel/sched/core.c:2800 [inline] __schedule+0x850/0x1e10 kernel/sched/core.c:3376 schedule+0x7c/0x1a0 kernel/sched/core.c:3435 io_schedule+0x1c/0x70 kernel/sched/core.c:5043 wait_on_page_bit_common mm/filemap.c:1099 [inline] wait_on_page_bit mm/filemap.c:1132 [inline] wait_on_page_locked include/linux/pagemap.h:530 [inline] __lock_page_or_retry+0x725/0x900 mm/filemap.c:1310 lock_page_or_retry include/linux/pagemap.h:510 [inline] filemap_fault+0xadf/0x1900 mm/filemap.c:2532 __do_fault+0x8a/0x1d0 mm/memory.c:3224 do_read_fault mm/memory.c:3634 [inline] do_fault mm/memory.c:3734 [inline] handle_pte_fault mm/memory.c:3965 [inline] __handle_mm_fault+0x1c96/0x3210 mm/memory.c:4089 handle_mm_fault+0x305/0x840 mm/memory.c:4126 faultin_page mm/gup.c:502 [inline] __get_user_pages+0x37e/0x1140 mm/gup.c:699 populate_vma_page_range+0x18e/0x230 mm/gup.c:1200 __mm_populate+0x204/0x350 mm/gup.c:1250 mm_populate include/linux/mm.h:2233 [inline] vm_mmap_pgoff+0x1e1/0x1f0 mm/util.c:338 SYSC_mmap_pgoff mm/mmap.c:1544 [inline] SyS_mmap_pgoff+0x423/0x580 mm/mmap.c:1502 SYSC_mmap arch/x86/kernel/sys_x86_64.c:100 [inline] SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:91 entry_SYSCALL_64_fastpath+0x23/0x9a RIP: 0033:0x452ac9 RSP: 002b:00007f3b2b3e0c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452ac9 RDX: 0000000000000003 RSI: 0000000000001000 RDI: 0000000020e5b000 RBP: 000000000000012c R08: 0000000000000015 R09: 0000000000000000 R10: 0000000000002011 R11: 0000000000000212 R12: 00000000006efcc0 R13: 00000000ffffffff R14: 00007f3b2b3e16d4 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by khungtaskd/739: #0: (rcu_read_lock){....}, at: [<00000000ba8339bb>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<00000000ba8339bb>] watchdog+0x122/0xab0 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<00000000fe6c8ea2>] debug_show_all_locks+0x70/0x280 kernel/locking/lockdep.c:4464 2 locks held by getty/3431: #0: (&tty->ldisc_sem){++++}, at: [<000000006c1e2202>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000150381dd>] n_tty_read+0x1ec/0x1660 drivers/tty/n_tty.c:2131 2 locks held by getty/3432: #0: (&tty->ldisc_sem){++++}, at: [<000000006c1e2202>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000150381dd>] n_tty_read+0x1ec/0x1660 drivers/tty/n_tty.c:2131 2 locks held by getty/3433: #0: (&tty->ldisc_sem){++++}, at: [<000000006c1e2202>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000150381dd>] n_tty_read+0x1ec/0x1660 drivers/tty/n_tty.c:2131 2 locks held by getty/3434: #0: (&tty->ldisc_sem){++++}, at: [<000000006c1e2202>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000150381dd>] n_tty_read+0x1ec/0x1660 drivers/tty/n_tty.c:2131 2 locks held by getty/3435: #0: (&tty->ldisc_sem){++++}, at: [<000000006c1e2202>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000150381dd>] n_tty_read+0x1ec/0x1660 drivers/tty/n_tty.c:2131 2 locks held by getty/3436: #0: (&tty->ldisc_sem){++++}, at: [<000000006c1e2202>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000150381dd>] n_tty_read+0x1ec/0x1660 drivers/tty/n_tty.c:2131 2 locks held by getty/3437: #0: (&tty->ldisc_sem){++++}, at: [<000000006c1e2202>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000150381dd>] n_tty_read+0x1ec/0x1660 drivers/tty/n_tty.c:2131 1 lock held by blkid/10875: #0: (&bdev->bd_mutex){+.+.}, at: [<000000004fc9e175>] __blkdev_put+0xbc/0x7c0 fs/block_dev.c:1756 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 739 Comm: khungtaskd Not tainted 4.15.0-rc6-next-20180105+ #89 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+0x137/0x198 lib/dump_stack.c:53 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x122/0x180 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+0x73d/0xab0 kernel/hung_task.c:249 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:524 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.15.0-rc6-next-20180105+ #89 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_is_held+0x10c/0x140 kernel/locking/lockdep.c:3743 RSP: 0018:ffff8801db407d00 EFLAGS: 00000082 RAX: 0000000000000000 RBX: 0000000000000282 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffffff85f280c0 RDI: ffffffff85e2cbda RBP: ffff8801db407d20 R08: ffffffff8145430f R09: 0000000000000002 R10: ffff8801db407cd8 R11: 0000000000000001 R12: ffffffff85e2c340 R13: fffffbfff0bc5976 R14: 0000000000000001 R15: ffffffff85e2cbb8 FS: 0000000000000000(0000) GS:ffff8801db400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000f0ce50 CR3: 0000000005e22002 CR4: 00000000001606f0 DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: lock_is_held_type+0x118/0x210 kernel/locking/lockdep.c:3952 lock_is_held include/linux/lockdep.h:344 [inline] rebalance_domains+0x7ea/0xaf0 kernel/sched/fair.c:9124 run_rebalance_domains+0x2c8/0x560 kernel/sched/fair.c:9382 __do_softirq+0x23f/0x99f kernel/softirq.c:285 invoke_softirq kernel/softirq.c:365 [inline] irq_exit+0x1cc/0x200 kernel/softirq.c:405 scheduler_ipi+0x2c5/0x450 kernel/sched/core.c:1804 smp_reschedule_interrupt+0x67/0x470 arch/x86/kernel/smp.c:277 reschedule_interrupt+0xa9/0xb0 arch/x86/entry/entry_64.S:944 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54 RSP: 0018:ffffffff85e07d00 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02 RAX: dffffc0000000000 RBX: ffffffff85e2c340 RCX: 0000000000000000 RDX: 1ffffffff0bd90a0 RSI: 0000000000000001 RDI: ffffffff85ec8500 RBP: ffffffff85e07d00 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff86638fe0 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:93 [inline] default_idle+0x52/0x310 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+0xbe/0xd0 kernel/sched/idle.c:351 rest_init+0xed/0xf0 init/main.c:436 start_kernel+0x77e/0x7a4 init/main.c:716 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:237 Code: 04 3c 03 7e 3e 0f b6 43 22 83 e0 03 3b 45 c4 0f 94 c0 48 83 c4 18 5b 0f b6 c0 41 5c 41 5d 41 5e 41 5f 5d c3 31 c0 48 83 c4 18 5b <41> 5c 41 5d 41 5e 41 5f 5d c3 48 8b 7d c8 e8 11 64 41 00 e9 2a