INFO: task syz-executor.5:7201 blocked for more than 140 seconds. Not tainted 4.14.101+ #14 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28600 7201 5195 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.5:7211 blocked for more than 140 seconds. Not tainted 4.14.101+ #14 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28768 7211 5195 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.5:7229 blocked for more than 140 seconds. Not tainted 4.14.101+ #14 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D29120 7229 5195 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.1:7219 blocked for more than 140 seconds. Not tainted 4.14.101+ #14 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28784 7219 5205 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 blkid:7207 blocked for more than 140 seconds. Not tainted 4.14.101+ #14 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D28248 7207 6006 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 blkid:7225 blocked for more than 140 seconds. Not tainted 4.14.101+ #14 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D27816 7225 3992 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 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 1 lock held by rsyslogd/1622: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0xa6/0xc0 fs/file.c:768 2 locks held by getty/1750: #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.5/7201: #0: (&bdev->bd_mutex){+.+.}, at: [] blkdev_put+0x27/0x4c0 fs/block_dev.c:1814 2 locks held by syz-executor.5/7211: #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.5/7229: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 2 locks held by syz-executor.1/7219: #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 2 locks held by blkid/7207: #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 blkid/7225: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 23 Comm: khungtaskd Not tainted 4.14.101+ #14 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 0xffffffffba641a92