INFO: task syz-executor4:2016 blocked for more than 140 seconds. Not tainted 4.14.67+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D27256 2016 1 0x00000004 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 lo_open+0x17/0xa0 drivers/block/loop.c:1592 __blkdev_get+0x267/0xe50 fs/block_dev.c:1467 blkdev_get+0x97/0x8c0 fs/block_dev.c:1604 blkdev_open+0x1bd/0x240 fs/block_dev.c:1762 do_dentry_open+0x426/0xda0 fs/open.c:764 vfs_open+0x11c/0x210 fs/open.c:878 do_last fs/namei.c:3408 [inline] path_openat+0x4eb/0x23a0 fs/namei.c:3550 do_filp_open+0x197/0x270 fs/namei.c:3584 do_sys_open+0x2ef/0x580 fs/open.c:1071 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x410da0 RSP: 002b:00007ffca27c9768 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000410da0 RDX: 00007ffca27c97aa RSI: 0000000000000002 RDI: 00007ffca27c97a0 RBP: 00000000000004f6 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000044a46 R14: 0000000000000130 R15: badc0ffeebadface INFO: task syz-executor5:10286 blocked for more than 140 seconds. Not tainted 4.14.67+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D27784 10286 1 0x00000004 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 lo_open+0x17/0xa0 drivers/block/loop.c:1592 __blkdev_get+0x267/0xe50 fs/block_dev.c:1467 blkdev_get+0x97/0x8c0 fs/block_dev.c:1604 blkdev_open+0x1bd/0x240 fs/block_dev.c:1762 do_dentry_open+0x426/0xda0 fs/open.c:764 vfs_open+0x11c/0x210 fs/open.c:878 do_last fs/namei.c:3408 [inline] path_openat+0x4eb/0x23a0 fs/namei.c:3550 do_filp_open+0x197/0x270 fs/namei.c:3584 do_sys_open+0x2ef/0x580 fs/open.c:1071 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x410da0 RSP: 002b:00007ffe90fe5108 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000410da0 RDX: 00007ffe90fe514a RSI: 0000000000000002 RDI: 00007ffe90fe5140 RBP: 00000000000004e6 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000007 R13: 0000000000044a23 R14: 000000000000012c R15: badc0ffeebadface INFO: task syz-executor3:15797 blocked for more than 140 seconds. Not tainted 4.14.67+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D27784 15797 1 0x00000004 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 lo_open+0x17/0xa0 drivers/block/loop.c:1592 __blkdev_get+0x267/0xe50 fs/block_dev.c:1467 blkdev_get+0x97/0x8c0 fs/block_dev.c:1604 blkdev_open+0x1bd/0x240 fs/block_dev.c:1762 do_dentry_open+0x426/0xda0 fs/open.c:764 vfs_open+0x11c/0x210 fs/open.c:878 do_last fs/namei.c:3408 [inline] path_openat+0x4eb/0x23a0 fs/namei.c:3550 do_filp_open+0x197/0x270 fs/namei.c:3584 do_sys_open+0x2ef/0x580 fs/open.c:1071 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x410da0 RSP: 002b:00007ffdd192f138 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000410da0 RDX: 00007ffdd192f17a RSI: 0000000000000002 RDI: 00007ffdd192f170 RBP: 00000000000002e1 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000009 R13: 0000000000044a1f R14: 0000000000000098 R15: badc0ffeebadface INFO: task syz-executor6:21870 blocked for more than 140 seconds. Not tainted 4.14.67+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor6 D28824 21870 2020 0x00000004 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1951 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x1a0/0x1030 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7e/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x457089 RSP: 002b:00007fab95261c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fab952626d4 RCX: 0000000000457089 RDX: 0000000000000000 RSI: 0000000000004c80 RDI: 0000000000000005 RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004cf6f8 R14: 00000000004c5abe R15: 0000000000000000 INFO: task syz-executor2:21873 blocked for more than 140 seconds. Not tainted 4.14.67+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D28824 21873 2013 0x00000004 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 loop_control_ioctl+0x180/0x310 drivers/block/loop.c:1965 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x1a0/0x1030 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7e/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x457089 RSP: 002b:00007fd8d6d13c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fd8d6d146d4 RCX: 0000000000457089 RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000004 RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004cf728 R14: 00000000004c5ae9 R15: 0000000000000000 INFO: task syz-executor2:21901 blocked for more than 140 seconds. Not tainted 4.14.67+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D29704 21901 2013 0x00000004 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1951 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x1a0/0x1030 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7e/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x457089 RSP: 002b:00007fd8d6cf2c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fd8d6cf36d4 RCX: 0000000000457089 RDX: 0000000000000000 RSI: 0000000000004c80 RDI: 0000000000000004 RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004cf6f8 R14: 00000000004c5abe R15: 0000000000000001 INFO: task syz-executor0:21879 blocked for more than 140 seconds. Not tainted 4.14.67+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D26552 21879 2014 0x00000004 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 blkdev_reread_part+0x18/0x30 block/ioctl.c:192 loop_reread_partitions+0x72/0x80 drivers/block/loop.c:614 loop_clr_fd+0x826/0xac0 drivers/block/loop.c:1068 lo_ioctl+0x6e6/0x17d0 drivers/block/loop.c:1383 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x57d/0x18c0 block/ioctl.c:594 block_ioctl+0xd9/0x120 fs/block_dev.c:1873 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x1a0/0x1030 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7e/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x456ef7 RSP: 002b:00007fbe9a342a18 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fbe9a3436d4 RCX: 0000000000456ef7 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000000c R10: 0000000000000064 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000004 R14: 0000000000000005 R15: 0000000000000007 INFO: task syz-executor0:21896 blocked for more than 140 seconds. Not tainted 4.14.67+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D28472 21896 2014 0x00000004 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 __blkdev_get+0xf3/0xe50 fs/block_dev.c:1452 blkdev_get+0x97/0x8c0 fs/block_dev.c:1604 blkdev_open+0x1bd/0x240 fs/block_dev.c:1762 do_dentry_open+0x426/0xda0 fs/open.c:764 vfs_open+0x11c/0x210 fs/open.c:878 do_last fs/namei.c:3408 [inline] path_openat+0x4eb/0x23a0 fs/namei.c:3550 do_filp_open+0x197/0x270 fs/namei.c:3584 do_sys_open+0x2ef/0x580 fs/open.c:1071 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x410dc1 RSP: 002b:00007fbe9a321a10 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007fbe9a3226d4 RCX: 0000000000410dc1 RDX: 00007fbe9a321baa RSI: 0000000000000002 RDI: 00007fbe9a321ba0 RBP: 0000000000000007 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000293 R12: 00007fbe9a3226d4 R13: 0000000000000007 R14: 0000000000000007 R15: 0000000000000007 INFO: task blkid:21887 blocked for more than 140 seconds. Not tainted 4.14.67+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D28520 21887 10947 0x00000004 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 lo_open+0x17/0xa0 drivers/block/loop.c:1592 __blkdev_get+0x8e2/0xe50 fs/block_dev.c:1529 blkdev_get+0x97/0x8c0 fs/block_dev.c:1604 blkdev_open+0x1bd/0x240 fs/block_dev.c:1762 do_dentry_open+0x426/0xda0 fs/open.c:764 vfs_open+0x11c/0x210 fs/open.c:878 do_last fs/namei.c:3408 [inline] path_openat+0x4eb/0x23a0 fs/namei.c:3550 do_filp_open+0x197/0x270 fs/namei.c:3584 do_sys_open+0x2ef/0x580 fs/open.c:1071 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f5cbbf5b120 RSP: 002b:00007fff22ed2c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5cbbf5b120 RDX: 00007fff22ed4f41 RSI: 0000000000000000 RDI: 00007fff22ed4f41 RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000001dba030 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005 Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x74/0x20f kernel/locking/lockdep.c:4541 2 locks held by getty/1925: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x20/0x80 drivers/tty/tty_ldisc.c:275 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1ff/0x15e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor4/2016: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xe50 fs/block_dev.c:1452 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x17/0xa0 drivers/block/loop.c:1592 2 locks held by syz-executor5/10286: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xe50 fs/block_dev.c:1452 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x17/0xa0 drivers/block/loop.c:1592 2 locks held by syz-executor3/15797: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xe50 fs/block_dev.c:1452 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x17/0xa0 drivers/block/loop.c:1592 1 lock held by syz-executor6/21870: #0: (loop_index_mutex){+.+.}, at: [] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1951 2 locks held by syz-executor2/21873: #0: (loop_index_mutex){+.+.}, at: [] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1951 #1: (&lo->lo_ctl_mutex#2){+.+.}, at: [] loop_control_ioctl+0x180/0x310 drivers/block/loop.c:1965 1 lock held by syz-executor2/21901: #0: (loop_index_mutex){+.+.}, at: [] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1951 2 locks held by syz-executor0/21879: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x85/0x17d0 drivers/block/loop.c:1373 #1: (&bdev->bd_mutex){+.+.}, at: [] blkdev_reread_part+0x18/0x30 block/ioctl.c:192 1 lock held by syz-executor0/21896: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xe50 fs/block_dev.c:1452 2 locks held by blkid/21887: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xe50 fs/block_dev.c:1452 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x17/0xa0 drivers/block/loop.c:1592 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 23 Comm: khungtaskd Not tainted 4.14.67+ #1 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x11b lib/dump_stack.c:53 nmi_cpu_backtrace.cold.0+0x18/0x8e lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x121/0x146 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:196 [inline] watchdog+0x574/0xa70 kernel/hung_task.c:252 kthread+0x348/0x420 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff9f840572