REISERFS warning (device loop6): sh-2021 reiserfs_fill_super: can not find reiserfs on loop6 REISERFS warning (device loop2): sh-2021 reiserfs_fill_super: can not find reiserfs on loop2 REISERFS warning (device loop1): sh-2021 reiserfs_fill_super: can not find reiserfs on loop1 REISERFS warning (device loop4): sh-2021 reiserfs_fill_super: can not find reiserfs on loop4 INFO: task syzkaller281197:26330 blocked for more than 120 seconds. Not tainted 4.17.0-rc1+ #9 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syzkaller281197 D22680 26330 4518 0x00000004 Call Trace: context_switch kernel/sched/core.c:2848 [inline] __schedule+0x801/0x1e30 kernel/sched/core.c:3490 schedule+0xef/0x430 kernel/sched/core.c:3549 blk_mq_freeze_queue_wait+0x1ce/0x460 block/blk-mq.c:136 blk_freeze_queue+0x4a/0x80 block/blk-mq.c:165 blk_mq_freeze_queue+0x15/0x20 block/blk-mq.c:174 loop_change_fd drivers/block/loop.c:667 [inline] lo_ioctl+0xa9a/0x2130 drivers/block/loop.c:1378 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x9b6/0x2020 block/ioctl.c:601 block_ioctl+0xee/0x130 fs/block_dev.c:1877 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x1cf/0x16a0 fs/ioctl.c:684 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701 __do_sys_ioctl fs/ioctl.c:708 [inline] __se_sys_ioctl fs/ioctl.c:706 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x445559 RSP: 002b:00007ffcb86ac908 EFLAGS: 00000286 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000016 RCX: 0000000000445559 RDX: 0000000000000004 RSI: 0000000000004c06 RDI: 0000000000000004 RBP: 0000000000000005 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000000a R11: 0000000000000286 R12: 0000000000000006 R13: 0000000000402dc0 R14: 00000000006d2440 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by khungtaskd/892: #0: 000000007e93ac19 (rcu_read_lock){....}, at: check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: 000000007e93ac19 (rcu_read_lock){....}, at: watchdog+0x1ff/0xf60 kernel/hung_task.c:249 #1: 00000000ec18d0f1 (tasklist_lock){.+.+}, at: debug_show_all_locks+0xde/0x34a kernel/locking/lockdep.c:4470 2 locks held by kworker/1:1H/1791: #0: 00000000095e3235 ((wq_completion)"kblockd"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 00000000095e3235 ((wq_completion)"kblockd"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000095e3235 ((wq_completion)"kblockd"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000095e3235 ((wq_completion)"kblockd"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:57 [inline] #0: 00000000095e3235 ((wq_completion)"kblockd"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000095e3235 ((wq_completion)"kblockd"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000095e3235 ((wq_completion)"kblockd"){+.+.}, at: process_one_work+0xaef/0x1b50 kernel/workqueue.c:2116 #1: 00000000da4adb07 ((work_completion)(&q->timeout_work)){+.+.}, at: process_one_work+0xb46/0x1b50 kernel/workqueue.c:2120 2 locks held by getty/4481: #0: 00000000bc42a659 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000473bcd6f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4482: #0: 000000002b468f04 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000005c3804c0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4483: #0: 00000000d598fa66 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000008e87a4e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4484: #0: 0000000028f2691c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000055198926 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4485: #0: 00000000ca961cfb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000021244f4f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4486: #0: 00000000f0441c12 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000032c20a78 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4487: #0: 00000000dad90e8d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000008174255a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 1 lock held by syzkaller281197/4511: #0: 00000000a288a2be (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8d/0x2130 drivers/block/loop.c:1369 1 lock held by syzkaller281197/26330: #0: 00000000a288a2be (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8d/0x2130 drivers/block/loop.c:1369 1 lock held by blkid/30285: #0: 00000000a288a2be (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8d/0x2130 drivers/block/loop.c:1369 1 lock held by syzkaller281197/30543: #0: 00000000a288a2be (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8d/0x2130 drivers/block/loop.c:1369 1 lock held by syzkaller281197/30548: #0: 00000000a288a2be (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8d/0x2130 drivers/block/loop.c:1369 1 lock held by syzkaller281197/30554: #0: 00000000a288a2be (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8d/0x2130 drivers/block/loop.c:1369 1 lock held by syzkaller281197/30560: #0: 00000000a288a2be (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8d/0x2130 drivers/block/loop.c:1369 1 lock held by syzkaller281197/30566: #0: 00000000a288a2be (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8d/0x2130 drivers/block/loop.c:1369 1 lock held by syzkaller281197/30568: #0: 00000000a288a2be (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8d/0x2130 drivers/block/loop.c:1369 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 892 Comm: khungtaskd Not tainted 4.17.0-rc1+ #9 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1b9/0x294 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x151/0x192 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+0xc10/0xf60 kernel/hung_task.c:249 kthread+0x345/0x410 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54