INFO: task syz-executor.0:1832 blocked for more than 140 seconds. Not tainted 4.14.141+ #40 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D25312 1832 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: 0033:0x4596e7 RSP: 002b:00007ffd85c1c2d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004596e7 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000003 RBP: 000000000000012f R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd85c1c310 R14: 000000000002884f R15: 00007ffd85c1c320 INFO: task syz-executor.5:5057 blocked for more than 140 seconds. Not tainted 4.14.141+ #40 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D25312 5057 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: 0033:0x413740 RSP: 002b:00007ffc476fb958 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000028bf9 RCX: 0000000000413740 RDX: 00007ffc476fb9ea RSI: 0000000000000002 RDI: 00007ffc476fb9e0 RBP: 00000000000000c0 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc476fb990 R14: 0000000000028be4 R15: 00007ffc476fb9a0 INFO: task syz-executor.1:7130 blocked for more than 140 seconds. Not tainted 4.14.141+ #40 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D25312 7130 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: 0033:0x413740 RSP: 002b:00007ffcfba1bee8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000028c09 RCX: 0000000000413740 RDX: 00007ffcfba1bf7a RSI: 0000000000000002 RDI: 00007ffcfba1bf70 RBP: 000000000000000e R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffcfba1bf20 R14: 0000000000028be1 R15: 00007ffcfba1bf30 INFO: task syz-executor.3:7373 blocked for more than 140 seconds. Not tainted 4.14.141+ #40 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28064 7373 4353 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: 0033:0x459879 RSP: 002b:00007fbaed579c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459879 RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000005 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fbaed57a6d4 R13: 00000000004c2fd2 R14: 00000000004d6718 R15: 00000000ffffffff INFO: task syz-executor.3:7376 blocked for more than 140 seconds. Not tainted 4.14.141+ #40 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D27488 7376 4353 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: 0033:0x459879 RSP: 002b:00007fbaed558c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459879 RDX: 0000000000000000 RSI: 0000000000004c80 RDI: 0000000000000005 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fbaed5596d4 R13: 00000000004c2fa7 R14: 00000000004d66e8 R15: 00000000ffffffff INFO: task blkid:7374 blocked for more than 140 seconds. Not tainted 4.14.141+ #40 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D28976 7374 4343 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: 0033:0x7f5accef1120 RSP: 002b:00007ffca006d308 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5accef1120 RDX: 00007ffca006ef41 RSI: 0000000000000000 RDI: 00007ffca006ef41 RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000d5b030 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005 Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: (tasklist_lock){.+.+}, at: [<00000000f3bf89b7>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4541 2 locks held by getty/1756: #0: (&tty->ldisc_sem){++++}, at: [<0000000068756b03>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c0b20de2>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.0/1832: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<000000008d7e9857>] lo_ioctl+0x86/0x1a30 drivers/block/loop.c:1404 #1: (&bdev->bd_mutex){+.+.}, at: [<000000004ee6bf94>] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 2 locks held by syz-executor.5/5057: #0: (&bdev->bd_mutex){+.+.}, at: [<000000002dccbde5>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<000000006ecb5dd1>] lo_open+0x19/0xb0 drivers/block/loop.c:1623 2 locks held by syz-executor.1/7130: #0: (&bdev->bd_mutex){+.+.}, at: [<000000002dccbde5>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<000000006ecb5dd1>] lo_open+0x19/0xb0 drivers/block/loop.c:1623 2 locks held by syz-executor.3/7373: #0: (loop_index_mutex){+.+.}, at: [<00000000d5861d99>] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1982 #1: (&lo->lo_ctl_mutex#2){+.+.}, at: [<000000003e9ee698>] loop_control_ioctl+0x183/0x310 drivers/block/loop.c:1996 1 lock held by syz-executor.3/7376: #0: (loop_index_mutex){+.+.}, at: [<00000000d5861d99>] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1982 2 locks held by blkid/7374: #0: (&bdev->bd_mutex){+.+.}, at: [<000000002dccbde5>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<000000006ecb5dd1>] lo_open+0x19/0xb0 drivers/block/loop.c:1623 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 23 Comm: khungtaskd Not tainted 4.14.141+ #40 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 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff9ce9b093