Buffer I/O error on dev loop0, logical block 0, async page read INFO: task syz-executor7:25067 blocked for more than 120 seconds. Not tainted 4.14.0-rc5-next-20171018+ #8 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor7 D22640 25067 3305 0x00000004 Call Trace: context_switch kernel/sched/core.c:2798 [inline] __schedule+0x8eb/0x2060 kernel/sched/core.c:3374 schedule+0xf5/0x430 kernel/sched/core.c:3433 io_schedule+0x1c/0x70 kernel/sched/core.c:5041 wait_on_page_bit_common+0x4b3/0x770 mm/filemap.c:1100 wait_on_page_bit mm/filemap.c:1133 [inline] wait_on_page_locked include/linux/pagemap.h:533 [inline] __lock_page_or_retry+0x3f7/0x4f0 mm/filemap.c:1310 lock_page_or_retry include/linux/pagemap.h:513 [inline] filemap_fault+0xcfa/0x1d30 mm/filemap.c:2532 __do_fault+0xeb/0x30f mm/memory.c:3196 do_read_fault mm/memory.c:3606 [inline] do_fault mm/memory.c:3706 [inline] handle_pte_fault mm/memory.c:3936 [inline] __handle_mm_fault+0x1b9b/0x39c0 mm/memory.c:4060 handle_mm_fault+0x334/0x8d0 mm/memory.c:4097 faultin_page mm/gup.c:502 [inline] __get_user_pages+0x50c/0x15f0 mm/gup.c:699 populate_vma_page_range+0x20e/0x2f0 mm/gup.c:1152 __mm_populate+0x23a/0x450 mm/gup.c:1202 mm_populate include/linux/mm.h:2208 [inline] vm_mmap_pgoff+0x241/0x280 mm/util.c:338 SYSC_mmap_pgoff mm/mmap.c:1518 [inline] SyS_mmap_pgoff+0x462/0x5f0 mm/mmap.c:1476 SYSC_mmap arch/x86/kernel/sys_x86_64.c:99 [inline] SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:90 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x447c89 RSP: 002b:00007ff26291cbd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007ff26291d6cc RCX: 0000000000447c89 RDX: 0000000000000001 RSI: 0000000000002000 RDI: 0000000020000000 RBP: 0000000000000082 R08: 0000000000000017 R09: 0000000000000000 R10: 0000000000002011 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ff26291d9c0 R15: 00007ff26291d700 Showing all locks held in the system: 2 locks held by khungtaskd/637: #0: (rcu_read_lock){....}, at: [] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0xd3/0x400 kernel/locking/lockdep.c:4541 1 lock held by rsyslogd/2879: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0x12b/0x190 fs/file.c:767 2 locks held by getty/2962: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2133 2 locks held by getty/2963: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2133 2 locks held by getty/2964: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2133 2 locks held by getty/2965: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2133 2 locks held by getty/2966: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2133 2 locks held by getty/2967: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2133 2 locks held by getty/13940: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2133 ============================================= NMI backtrace for cpu 3 CPU: 3 PID: 637 Comm: khungtaskd Not tainted 4.14.0-rc5-next-20171018+ #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 nmi_cpu_backtrace+0x20e/0x240 lib/nmi_backtrace.c:102 nmi_trigger_cpumask_backtrace+0x122/0x180 lib/nmi_backtrace.c:61 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 trigger_all_cpu_backtrace include/linux/nmi.h:137 [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+0x38b/0x470 kernel/kthread.c:242 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 Sending NMI from CPU 3 to CPUs 0-2: NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff84e54ea6 NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff84e54ea6 NMI backtrace for cpu 2 skipped: idling at pc 0xffffffff84e54ea6