INFO: task syz-executor.0:10924 blocked for more than 140 seconds. Not tainted 4.14.142+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D25200 10924 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 loop_reread_partitions+0x7f/0x90 drivers/block/loop.c:614 loop_clr_fd+0x835/0xad0 drivers/block/loop.c:1068 lo_ioctl+0x460/0x1a30 drivers/block/loop.c:1414 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x8d0/0x1870 block/ioctl.c:594 block_ioctl+0xd9/0x120 fs/block_dev.c:1881 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0xabe/0x1040 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x459757 RSP: 002b:00007fffcc1c79f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459757 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000003 RBP: 00000000000009fa R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffcc1c7a30 R14: 00000000000c023d R15: 00007fffcc1c7a40 INFO: task syz-executor.1:14586 blocked for more than 140 seconds. Not tainted 4.14.142+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D25312 14586 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1623 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xe20 fs/open.c:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4137b0 RSP: 002b:00007ffe41db3a88 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000064 RCX: 00000000004137b0 RDX: 00007ffe41db3b1a RSI: 0000000000000002 RDI: 00007ffe41db3b10 RBP: 00000000000008b5 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe41db3ac0 R14: 00000000000c03e4 R15: 00007ffe41db3ad0 INFO: task syz-executor.3:16950 blocked for more than 140 seconds. Not tainted 4.14.142+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D25008 16950 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1623 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xe20 fs/open.c:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4137b0 RSP: 002b:00007ffd4f389298 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00000000000c03a8 RCX: 00000000004137b0 RDX: 00007ffd4f38932a RSI: 0000000000000002 RDI: 00007ffd4f389320 RBP: 000000000000070c R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd4f3892d0 R14: 00000000000c0331 R15: 00007ffd4f3892e0 INFO: task syz-executor.4:25629 blocked for more than 140 seconds. Not tainted 4.14.142+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D25312 25629 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1623 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xe20 fs/open.c:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4137b0 RSP: 002b:00007fffac5c0bd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00000000000c0572 RCX: 00000000004137b0 RDX: 00007fffac5c0c6a RSI: 0000000000000002 RDI: 00007fffac5c0c60 RBP: 0000000000000382 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffac5c0c10 R14: 00000000000c023c R15: 00007fffac5c0c20 INFO: task syz-executor.2:32485 blocked for more than 140 seconds. Not tainted 4.14.142+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D25312 32485 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1623 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xe20 fs/open.c:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4137b0 RSP: 002b:00007fff1873d6d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 000000000000005e RCX: 00000000004137b0 RDX: 00007fff1873d76a RSI: 0000000000000002 RDI: 00007fff1873d760 RBP: 00000000000000d0 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff1873d710 R14: 00000000000c0244 R15: 00007fff1873d720 INFO: task syz-executor.5:1959 blocked for more than 140 seconds. Not tainted 4.14.142+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28352 1959 939 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 loop_control_ioctl+0x183/0x310 drivers/block/loop.c:1996 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0xabe/0x1040 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4598e9 RSP: 002b:00007f83ecf78c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004598e9 RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000007 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f83ecf796d4 R13: 00000000004c300b R14: 00000000004d6798 R15: 00000000ffffffff INFO: task syz-executor.5:1967 blocked for more than 140 seconds. Not tainted 4.14.142+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D27264 1967 939 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1982 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0xabe/0x1040 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4598e9 RSP: 002b:00007f83ecf57c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004598e9 RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000007 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f83ecf586d4 R13: 00000000004c300b R14: 00000000004d6798 R15: 00000000ffffffff INFO: task blkid:1962 blocked for more than 140 seconds. Not tainted 4.14.142+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D28848 1962 30160 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1623 __blkdev_get+0x963/0xf90 fs/block_dev.c:1537 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xe20 fs/open.c:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7fd42d7b8120 RSP: 002b:00007ffc7a14f668 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd42d7b8120 RDX: 00007ffc7a151f41 RSI: 0000000000000000 RDI: 00007ffc7a151f41 RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000023dc030 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005 Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: (tasklist_lock){.+.+}, at: [<00000000c968225b>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4541 2 locks held by getty/1760: #0: (&tty->ldisc_sem){++++}, at: [<00000000b37083d8>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000003a829cb3>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.0/10924: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000bd0217bf>] lo_ioctl+0x86/0x1a30 drivers/block/loop.c:1404 #1: (&bdev->bd_mutex){+.+.}, at: [<00000000d853772e>] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 2 locks held by syz-executor.1/14586: #0: (&bdev->bd_mutex){+.+.}, at: [<000000006b2cc125>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<0000000049135cc4>] lo_open+0x19/0xb0 drivers/block/loop.c:1623 2 locks held by syz-executor.3/16950: #0: (&bdev->bd_mutex){+.+.}, at: [<000000006b2cc125>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<0000000049135cc4>] lo_open+0x19/0xb0 drivers/block/loop.c:1623 2 locks held by syz-executor.4/25629: #0: (&bdev->bd_mutex){+.+.}, at: [<000000006b2cc125>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<0000000049135cc4>] lo_open+0x19/0xb0 drivers/block/loop.c:1623 2 locks held by syz-executor.2/32485: #0: (&bdev->bd_mutex){+.+.}, at: [<000000006b2cc125>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<0000000049135cc4>] lo_open+0x19/0xb0 drivers/block/loop.c:1623 2 locks held by syz-executor.5/1959: #0: (loop_index_mutex){+.+.}, at: [<000000002952e339>] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1982 #1: (&lo->lo_ctl_mutex#2){+.+.}, at: [<0000000016f1abdf>] loop_control_ioctl+0x183/0x310 drivers/block/loop.c:1996 1 lock held by syz-executor.5/1967: #0: (loop_index_mutex){+.+.}, at: [<000000002952e339>] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1982 2 locks held by blkid/1962: #0: (&bdev->bd_mutex){+.+.}, at: [<000000006b2cc125>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<0000000049135cc4>] lo_open+0x19/0xb0 drivers/block/loop.c:1623 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 23 Comm: khungtaskd Not tainted 4.14.142+ #0 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xca/0x134 lib/dump_stack.c:53 nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x119/0x147 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x629/0xbe0 kernel/hung_task.c:274 kthread+0x31f/0x430 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at pc 0xffffffffa3e9b273