INFO: task syz-executor.1:7088 blocked for more than 140 seconds. Not tainted 4.14.113 #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D24992 7088 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 __lo_release drivers/block/loop.c:1644 [inline] lo_release+0x84/0x1b0 drivers/block/loop.c:1668 __blkdev_put+0x436/0x7f0 fs/block_dev.c:1791 blkdev_put+0x88/0x510 fs/block_dev.c:1856 blkdev_close+0x8b/0xb0 fs/block_dev.c:1863 __fput+0x277/0x7a0 fs/file_table.c:210 ____fput+0x16/0x20 fs/file_table.c:244 task_work_run+0x119/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1da/0x220 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:267 [inline] do_syscall_64+0x4a9/0x630 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x412b40 RSP: 002b:00007fffec96b438 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000412b40 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000003 RBP: 0000000000000202 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffec96b470 R14: 000000000003c3d7 R15: 00007fffec96b480 INFO: task syz-executor.5:7089 blocked for more than 140 seconds. Not tainted 4.14.113 #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D24992 7089 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 lo_open+0x1d/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x2c9/0x1120 fs/block_dev.c:1472 blkdev_get+0xa8/0x8e0 fs/block_dev.c:1612 blkdev_open+0x1d1/0x260 fs/block_dev.c:1770 do_dentry_open+0x73e/0xeb0 fs/open.c:758 vfs_open+0x105/0x230 fs/open.c:872 do_last fs/namei.c:3425 [inline] path_openat+0x8bd/0x3f70 fs/namei.c:3566 do_filp_open+0x18e/0x250 fs/namei.c:3600 do_sys_open+0x2c5/0x430 fs/open.c:1065 SYSC_open fs/open.c:1083 [inline] SyS_open+0x2d/0x40 fs/open.c:1078 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x412d20 RSP: 002b:00007ffca86bd058 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 000000000003c46b RCX: 0000000000412d20 RDX: 00007ffca86bd0ea RSI: 0000000000000002 RDI: 00007ffca86bd0e0 RBP: 00000000000001d2 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffca86bd090 R14: 000000000003c3e0 R15: 00007ffca86bd0a0 INFO: task syz-executor.3:7090 blocked for more than 140 seconds. Not tainted 4.14.113 #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D25008 7090 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 lo_ioctl+0x87/0x1c70 drivers/block/loop.c:1405 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x983/0x1880 block/ioctl.c:594 block_ioctl+0xde/0x120 fs/block_dev.c:1881 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x7b9/0x1070 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x458c17 RSP: 002b:00007ffdc6278c48 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458c17 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000003 RBP: 00000000000001b4 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffdc6278c80 R14: 000000000003c3e4 R15: 00007ffdc6278c90 INFO: task syz-executor.2:11000 blocked for more than 140 seconds. Not tainted 4.14.113 #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D29152 11000 7085 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 lo_open+0x1d/0xb0 drivers/block/loop.c:1624 __blkdev_get+0xab1/0x1120 fs/block_dev.c:1537 blkdev_get+0xa8/0x8e0 fs/block_dev.c:1612 blkdev_open+0x1d1/0x260 fs/block_dev.c:1770 do_dentry_open+0x73e/0xeb0 fs/open.c:758 vfs_open+0x105/0x230 fs/open.c:872 do_last fs/namei.c:3425 [inline] path_openat+0x8bd/0x3f70 fs/namei.c:3566 do_filp_open+0x18e/0x250 fs/namei.c:3600 do_sys_open+0x2c5/0x430 fs/open.c:1065 SYSC_open fs/open.c:1083 [inline] SyS_open+0x2d/0x40 fs/open.c:1078 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x412d41 RSP: 002b:00007f8d33c46a80 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000020001540 RCX: 0000000000412d41 RDX: 00007f8d33c46b0a RSI: 0000000000000002 RDI: 00007f8d33c46b00 RBP: 0000000000000002 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000293 R12: 0000000000000007 R13: 00000000004c7956 R14: 00000000004dd988 R15: 00000000ffffffff INFO: task syz-executor.4:10996 blocked for more than 140 seconds. Not tainted 4.14.113 #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D29120 10996 7087 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 blkdev_reread_part+0x1f/0x40 block/ioctl.c:192 loop_reread_partitions+0x7c/0x90 drivers/block/loop.c:615 loop_set_status+0xc28/0x1200 drivers/block/loop.c:1184 loop_set_status64+0xa6/0xf0 drivers/block/loop.c:1302 lo_ioctl+0x5c1/0x1c70 drivers/block/loop.c:1432 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x983/0x1880 block/ioctl.c:594 block_ioctl+0xde/0x120 fs/block_dev.c:1881 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x7b9/0x1070 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x458c17 RSP: 002b:00007f19f17369f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f19f17376d4 RCX: 0000000000458c17 RDX: 00007f19f1736ab0 RSI: 0000000000004c04 RDI: 0000000000000005 RBP: 0000000000000001 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000202 R12: 0000000000000004 R13: 0000000000000004 R14: 0000000000000005 R15: 00000000ffffffff INFO: task syz-executor.4:11009 blocked for more than 140 seconds. Not tainted 4.14.113 #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D29184 11009 7087 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 blkdev_get+0xa8/0x8e0 fs/block_dev.c:1612 blkdev_open+0x1d1/0x260 fs/block_dev.c:1770 do_dentry_open+0x73e/0xeb0 fs/open.c:758 vfs_open+0x105/0x230 fs/open.c:872 do_last fs/namei.c:3425 [inline] path_openat+0x8bd/0x3f70 fs/namei.c:3566 do_filp_open+0x18e/0x250 fs/namei.c:3600 do_sys_open+0x2c5/0x430 fs/open.c:1065 SYSC_open fs/open.c:1083 [inline] SyS_open+0x2d/0x40 fs/open.c:1078 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x412d41 RSP: 002b:00007f19f17159f0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007f19f17166d4 RCX: 0000000000412d41 RDX: 00007f19f1715baa RSI: 0000000000000002 RDI: 00007f19f1715ba0 RBP: 0000000000000001 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000293 R12: 0000000000000004 R13: 0000000000000004 R14: 00007f19f17166d4 R15: 00000000ffffffff INFO: task blkid:10997 blocked for more than 140 seconds. Not tainted 4.14.113 #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D29040 10997 7047 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 lo_ioctl+0x87/0x1c70 drivers/block/loop.c:1405 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x983/0x1880 block/ioctl.c:594 block_ioctl+0xde/0x120 fs/block_dev.c:1881 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x7b9/0x1070 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f5e85c15347 RSP: 002b:00007ffc84cb9e08 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000b32030 RCX: 00007f5e85c15347 RDX: 0000000000000000 RSI: 0000000000005331 RDI: 0000000000000003 RBP: 0000000000000003 R08: 00007f5e85ec55a0 R09: 0000000000000008 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000200 R14: 0000000000000003 R15: 0000000000000005 INFO: task blkid:11005 blocked for more than 140 seconds. Not tainted 4.14.113 #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D29040 11005 7048 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 blkdev_get+0xa8/0x8e0 fs/block_dev.c:1612 blkdev_open+0x1d1/0x260 fs/block_dev.c:1770 do_dentry_open+0x73e/0xeb0 fs/open.c:758 vfs_open+0x105/0x230 fs/open.c:872 do_last fs/namei.c:3425 [inline] path_openat+0x8bd/0x3f70 fs/namei.c:3566 do_filp_open+0x18e/0x250 fs/namei.c:3600 do_sys_open+0x2c5/0x430 fs/open.c:1065 SYSC_open fs/open.c:1083 [inline] SyS_open+0x2d/0x40 fs/open.c:1078 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f0f1f81a120 RSP: 002b:00007fffc25bfd38 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0f1f81a120 RDX: 00007fffc25c1f34 RSI: 0000000000000000 RDI: 00007fffc25c1f34 RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000be6030 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005 INFO: task blkid:11008 blocked for more than 140 seconds. Not tainted 4.14.113 #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D29040 11008 7274 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 lo_open+0x1d/0xb0 drivers/block/loop.c:1624 __blkdev_get+0xab1/0x1120 fs/block_dev.c:1537 blkdev_get+0xa8/0x8e0 fs/block_dev.c:1612 blkdev_open+0x1d1/0x260 fs/block_dev.c:1770 do_dentry_open+0x73e/0xeb0 fs/open.c:758 vfs_open+0x105/0x230 fs/open.c:872 do_last fs/namei.c:3425 [inline] path_openat+0x8bd/0x3f70 fs/namei.c:3566 do_filp_open+0x18e/0x250 fs/namei.c:3600 do_sys_open+0x2c5/0x430 fs/open.c:1065 SYSC_open fs/open.c:1083 [inline] SyS_open+0x2d/0x40 fs/open.c:1078 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f01cf621120 RSP: 002b:00007ffc008be2b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f01cf621120 RDX: 00007ffc008bef41 RSI: 0000000000000000 RDI: 00007ffc008bef41 RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000001b7a030 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005 Showing all locks held in the system: 1 lock held by khungtaskd/1008: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4544 1 lock held by rsyslogd/6917: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0xab/0xd0 fs/file.c:769 2 locks held by getty/7040: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/7041: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/7042: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/7043: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/7044: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/7045: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/7046: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 3 locks held by syz-executor.1/7088: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_put+0xa6/0x7f0 fs/block_dev.c:1778 #1: (loop_index_mutex){+.+.}, at: [] lo_release+0x1e/0x1b0 drivers/block/loop.c:1667 #2: (loop_ctl_mutex#2){+.+.}, at: [] __lo_release drivers/block/loop.c:1644 [inline] #2: (loop_ctl_mutex#2){+.+.}, at: [] lo_release+0x84/0x1b0 drivers/block/loop.c:1668 2 locks held by syz-executor.5/7089: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x1d/0xb0 drivers/block/loop.c:1624 1 lock held by syz-executor.3/7090: #0: (loop_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x87/0x1c70 drivers/block/loop.c:1405 2 locks held by syz-executor.2/11000: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x1d/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.4/10996: #0: (loop_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x87/0x1c70 drivers/block/loop.c:1405 #1: (&bdev->bd_mutex){+.+.}, at: [] blkdev_reread_part+0x1f/0x40 block/ioctl.c:192 1 lock held by syz-executor.4/11009: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 1 lock held by blkid/10997: #0: (loop_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x87/0x1c70 drivers/block/loop.c:1405 1 lock held by blkid/11005: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 2 locks held by blkid/11008: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x1d/0xb0 drivers/block/loop.c:1624 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1008 Comm: khungtaskd Not tainted 4.14.113 #3 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x138/0x19c lib/dump_stack.c:53 nmi_cpu_backtrace.cold+0x57/0x94 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x141/0x189 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:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5e7/0xb90 kernel/hung_task.c:274 kthread+0x31c/0x430 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5 Comm: kworker/u4:0 Not tainted 4.14.113 #3 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker task: ffff8880a9cc2140 task.stack: ffff8880a9cd0000 RIP: 0010:rcu_read_unlock_sched_notrace include/linux/rcupdate.h:777 [inline] RIP: 0010:trace_lock_release include/trace/events/lock.h:58 [inline] RIP: 0010:lock_release+0x5f5/0x940 kernel/locking/lockdep.c:4012 RSP: 0018:ffff8880a9cd7ba8 EFLAGS: 00000082 RAX: 0000000000000000 RBX: 1ffff1101539af7b RCX: 1ffffffff0f563a0 RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffff8880a9cc29bc RBP: ffff8880a9cd7c40 R08: 0000000000000496 R09: ffffffff88c7b870 R10: 0000000000000000 R11: ffff8880a9cc2140 R12: ffff8880656a58d8 R13: ffffffff860359a5 R14: ffff8880a9cc2140 R15: ffff8880a9cd7c18 FS: 0000000000000000(0000) GS:ffff8880aee00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f17c46b049d CR3: 0000000090592000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:174 [inline] _raw_spin_unlock_bh+0x1b/0x40 kernel/locking/spinlock.c:208 spin_unlock_bh include/linux/spinlock.h:362 [inline] batadv_nc_purge_paths+0x245/0x350 net/batman-adv/network-coding.c:479 batadv_nc_worker+0x23d/0x6d0 net/batman-adv/network-coding.c:727 process_one_work+0x868/0x1610 kernel/workqueue.c:2114 worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248 kthread+0x31c/0x430 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402 Code: 65 ff 05 ef a7 b9 7e 48 8b 05 40 31 d9 06 e8 63 e4 04 00 85 c0 74 0d 80 3d 8c dc d8 06 00 0f 84 07 01 00 00 65 ff 0d cb a7 b9 7e <0f> 85 71 fb ff ff e8 74 fc b7 ff e9 67 fb ff ff 0f 0b 0f 0b 0f