INFO: task syz-executor.2:13593 blocked for more than 140 seconds. Not tainted 4.14.108+ #36 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28344 13593 1847 0x80000002 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+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 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x903/0x2960 kernel/exit.c:873 INFO: task syz-executor.3:14432 blocked for more than 140 seconds. Not tainted 4.14.108+ #36 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28344 14432 1846 0x80000002 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+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 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x903/0x2960 kernel/exit.c:873 INFO: task syz-executor.2:14462 blocked for more than 140 seconds. Not tainted 4.14.108+ #36 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28344 14462 1847 0x80000002 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+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 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x903/0x2960 kernel/exit.c:873 INFO: task syz-executor.3:14464 blocked for more than 140 seconds. Not tainted 4.14.108+ #36 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28344 14464 1846 0x80000002 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+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 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x903/0x2960 kernel/exit.c:873 INFO: task syz-executor.1:14465 blocked for more than 140 seconds. Not tainted 4.14.108+ #36 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28208 14465 1856 0x80000002 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+0x559/0x1430 kernel/locking/mutex.c:893 lo_release+0x19/0x190 drivers/block/loop.c:1667 __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 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x903/0x2960 kernel/exit.c:873 INFO: task syz-executor.3:14480 blocked for more than 140 seconds. Not tainted 4.14.108+ #36 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28344 14480 1846 0x80000002 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+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 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x903/0x2960 kernel/exit.c:873 INFO: task syz-executor.3:14487 blocked for more than 140 seconds. Not tainted 4.14.108+ #36 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28344 14487 1846 0x80000002 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+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 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x903/0x2960 kernel/exit.c:873 INFO: task syz-executor.2:14504 blocked for more than 140 seconds. Not tainted 4.14.108+ #36 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28344 14504 1847 0x80000002 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+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 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x903/0x2960 kernel/exit.c:873 INFO: task syz-executor.3:14505 blocked for more than 140 seconds. Not tainted 4.14.108+ #36 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28344 14505 1846 0x80000002 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+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 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x903/0x2960 kernel/exit.c:873 INFO: task syz-executor.2:14841 blocked for more than 140 seconds. Not tainted 4.14.108+ #36 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28344 14841 1847 0x80000002 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+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 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x903/0x2960 kernel/exit.c:873 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 2 locks held by getty/1755: #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.2/13593: #0: (&bdev->bd_mutex){+.+.}, at: [] blkdev_put+0x27/0x4c0 fs/block_dev.c:1814 1 lock held by syz-executor.3/14432: #0: (&bdev->bd_mutex){+.+.}, at: [] blkdev_put+0x27/0x4c0 fs/block_dev.c:1814 1 lock held by syz-executor.2/14462: #0: (&bdev->bd_mutex){+.+.}, at: [] blkdev_put+0x27/0x4c0 fs/block_dev.c:1814 1 lock held by syz-executor.3/14464: #0: (&bdev->bd_mutex){+.+.}, at: [] blkdev_put+0x27/0x4c0 fs/block_dev.c:1814 2 locks held by syz-executor.1/14465: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_put+0xb1/0x6d0 fs/block_dev.c:1778 #1: (loop_index_mutex){+.+.}, at: [] lo_release+0x19/0x190 drivers/block/loop.c:1667 1 lock held by syz-executor.3/14480: #0: (&bdev->bd_mutex){+.+.}, at: [] blkdev_put+0x27/0x4c0 fs/block_dev.c:1814 1 lock held by syz-executor.3/14487: #0: (&bdev->bd_mutex){+.+.}, at: [] blkdev_put+0x27/0x4c0 fs/block_dev.c:1814 1 lock held by syz-executor.2/14504: #0: (&bdev->bd_mutex){+.+.}, at: [] blkdev_put+0x27/0x4c0 fs/block_dev.c:1814 1 lock held by syz-executor.3/14505: #0: (&bdev->bd_mutex){+.+.}, at: [] blkdev_put+0x27/0x4c0 fs/block_dev.c:1814 1 lock held by syz-executor.2/14841: #0: (&bdev->bd_mutex){+.+.}, at: [] blkdev_put+0x27/0x4c0 fs/block_dev.c:1814 3 locks held by syz-executor.1/11426: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_put+0xb1/0x6d0 fs/block_dev.c:1778 #1: (loop_index_mutex){+.+.}, at: [] lo_release+0x19/0x190 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+0x78/0x190 drivers/block/loop.c:1668 2 locks held by syz-executor.5/11431: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.2/11435: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.3/11453: #0: (loop_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x83/0x1970 drivers/block/loop.c:1405 #1: (&bdev->bd_mutex){+.+.}, at: [] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 1 lock held by blkid/11467: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 2 locks held by blkid/11470: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x19/0xb0 drivers/block/loop.c:1624 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 23 Comm: khungtaskd Not tainted 4.14.108+ #36 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 skipped: idling at pc 0xffffffff95446922