INFO: task syz-executor.1:27558 blocked for more than 140 seconds. Not tainted 4.14.103+ #18 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28808 27558 22996 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3495 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3553 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 blkdev_put+0x27/0x4c0 fs/block_dev.c:1814 blkdev_close+0x86/0xb0 fs/block_dev.c:1863 __fput+0x25e/0x700 fs/file_table.c:210 task_work_run+0x118/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x13b/0x160 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+0x372/0x4b0 arch/x86/entry/common.c:294 INFO: task syz-executor.1:27563 blocked for more than 140 seconds. Not tainted 4.14.103+ #18 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28448 27563 22996 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3495 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3553 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 lo_release+0x19/0x170 drivers/block/loop.c:1643 __blkdev_put+0x518/0x6d0 fs/block_dev.c:1791 deactivate_locked_super+0x71/0xd0 fs/super.c:319 mount_bdev+0x322/0x360 fs/super.c:1151 mount_fs+0x277/0x312 fs/super.c:1255 vfs_kern_mount.part.0+0xc7/0x4a0 fs/namespace.c:1056 vfs_kern_mount fs/namespace.c:1038 [inline] do_new_mount fs/namespace.c:2573 [inline] do_mount+0x3f6/0x26a0 fs/namespace.c:2903 SYSC_mount fs/namespace.c:3119 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3096 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task syz-executor.1:27567 blocked for more than 140 seconds. Not tainted 4.14.103+ #18 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28688 27567 22996 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3495 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3553 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x41b/0xd60 fs/open.c:764 vfs_open+0x105/0x230 fs/open.c:878 do_last fs/namei.c:3455 [inline] path_openat+0xb6b/0x2b70 fs/namei.c:3597 do_filp_open+0x1a1/0x280 fs/namei.c:3631 do_sys_open+0x2ca/0x590 fs/open.c:1071 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task blkid:27560 blocked for more than 140 seconds. Not tainted 4.14.103+ #18 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D28672 27560 23660 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3495 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3553 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 lo_release+0x19/0x170 drivers/block/loop.c:1643 __blkdev_put+0x518/0x6d0 fs/block_dev.c:1791 blkdev_close+0x86/0xb0 fs/block_dev.c:1863 __fput+0x25e/0x700 fs/file_table.c:210 task_work_run+0x118/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x13b/0x160 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+0x372/0x4b0 arch/x86/entry/common.c:294 INFO: task syz-executor.0:27564 blocked for more than 140 seconds. Not tainted 4.14.103+ #18 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28600 27564 22952 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3495 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3553 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 loop_reread_partitions+0x72/0x80 drivers/block/loop.c:614 loop_set_status+0xbff/0x11f0 drivers/block/loop.c:1183 INFO: task syz-executor.0:27578 blocked for more than 140 seconds. Not tainted 4.14.103+ #18 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D27744 27578 22952 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3495 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3553 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x41b/0xd60 fs/open.c:764 vfs_open+0x105/0x230 fs/open.c:878 do_last fs/namei.c:3455 [inline] path_openat+0xb6b/0x2b70 fs/namei.c:3597 do_filp_open+0x1a1/0x280 fs/namei.c:3631 do_sys_open+0x2ca/0x590 fs/open.c:1071 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task syz-executor.0:27583 blocked for more than 140 seconds. Not tainted 4.14.103+ #18 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D29152 27583 22952 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3495 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3553 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x41b/0xd60 fs/open.c:764 vfs_open+0x105/0x230 fs/open.c:878 do_last fs/namei.c:3455 [inline] path_openat+0xb6b/0x2b70 fs/namei.c:3597 do_filp_open+0x1a1/0x280 fs/namei.c:3631 do_sys_open+0x2ca/0x590 fs/open.c:1071 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task syz-executor.4:27572 blocked for more than 140 seconds. Not tainted 4.14.103+ #18 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28432 27572 23004 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3495 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3553 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 lo_ioctl+0x83/0x1970 drivers/block/loop.c:1404 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x4d9/0x1810 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/0x4b0 arch/x86/entry/common.c:289 INFO: task blkid:27571 blocked for more than 140 seconds. Not tainted 4.14.103+ #18 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D28432 27571 4545 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3495 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3553 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 lo_ioctl+0x83/0x1970 drivers/block/loop.c:1404 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x4d9/0x1810 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/0x4b0 arch/x86/entry/common.c:289 Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4541 4 locks held by rs:main Q:Reg/1630: #0: (&rq->lock){-.-.}, at: [] idle_balance kernel/sched/fair.c:10758 [inline] #0: (&rq->lock){-.-.}, at: [] pick_next_task_fair+0x793/0x2860 kernel/sched/fair.c:8373 #1: (sb_writers#4){.+.+}, at: [] file_start_write include/linux/fs.h:2726 [inline] #1: (sb_writers#4){.+.+}, at: [] vfs_write+0x3d8/0x4d0 fs/read_write.c:545 #2: (rcu_read_lock){....}, at: [] dput.part.0+0x27/0x710 fs/dcache.c:809 #3: (&rq->lock){-.-.}, at: [] idle_balance kernel/sched/fair.c:10758 [inline] #3: (&rq->lock){-.-.}, at: [] pick_next_task_fair+0x793/0x2860 kernel/sched/fair.c:8373 2 locks held by getty/1760: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:275 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.1/27558: #0: (&bdev->bd_mutex){+.+.}, at: [] blkdev_put+0x27/0x4c0 fs/block_dev.c:1814 2 locks held by syz-executor.1/27563: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_put+0xb1/0x6d0 fs/block_dev.c:1778 #1: (loop_ctl_mutex){+.+.}, at: [] lo_release+0x19/0x170 drivers/block/loop.c:1643 1 lock held by syz-executor.1/27567: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 2 locks held by blkid/27560: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_put+0xb1/0x6d0 fs/block_dev.c:1778 #1: (loop_ctl_mutex){+.+.}, at: [] lo_release+0x19/0x170 drivers/block/loop.c:1643 2 locks held by syz-executor.0/27564: #0: (loop_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x83/0x1970 drivers/block/loop.c:1404 #1: (&bdev->bd_mutex){+.+.}, at: [] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 1 lock held by syz-executor.0/27578: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 1 lock held by syz-executor.0/27583: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 1 lock held by syz-executor.4/27572: #0: (loop_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x83/0x1970 drivers/block/loop.c:1404 1 lock held by blkid/27571: #0: (loop_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x83/0x1970 drivers/block/loop.c:1404 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 23 Comm: khungtaskd Not tainted 4.14.103+ #18 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x10e lib/dump_stack.c:53 nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 22684 Comm: kworker/1:2 Not tainted 4.14.103+ #18 Workqueue: events free_obj_work task: ffff8881a9510000 task.stack: ffff8881d6708000 RIP: 0010:match_held_lock kernel/locking/lockdep.c:3555 [inline] RIP: 0010:__lock_is_held+0x7f/0x160 kernel/locking/lockdep.c:3811 RSP: 0018:ffff8881d670fcc8 EFLAGS: 00000046 RAX: 1ffff110352a210d RBX: ffff8881a9510858 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff8881a9510868 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881a9510830 R13: ffffffff8a8d3560 R14: dffffc0000000000 R15: ffff8881a9510000 FS: 0000000000000000(0000) GS:ffff8881dbb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa91ad7f000 CR3: 000000003d426006 CR4: 00000000001606a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: lock_is_held_type+0xb3/0x150 kernel/locking/lockdep.c:4029 lock_is_held include/linux/lockdep.h:437 [inline] rcu_read_lock_sched_held+0x10a/0x130 kernel/rcu/update.c:116 trace_workqueue_execute_end include/trace/events/workqueue.h:112 [inline] process_one_work+0x109e/0x14e0 kernel/workqueue.c:2119 worker_thread+0x5d7/0x1080 kernel/workqueue.c:2248 kthread+0x310/0x420 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402 Code: 00 00 fc ff df 4d 8d a7 30 08 00 00 85 c0 7e 6f 48 63 c5 48 8d 04 80 49 8d 1c c4 48 8d 7b 10 48 89 f8 48 c1 e8 03 42 80 3c 30 00 <0f> 85 bd 00 00 00 4c 3b 6b 10 74 59 48 8d 7b 22 48 89 f8 48 c1