INFO: task syz-executor.0:3977 blocked for more than 140 seconds. Not tainted 4.14.102+ #17 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28600 3977 1851 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.0:3994 blocked for more than 140 seconds. Not tainted 4.14.102+ #17 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28576 3994 1851 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+0x48f/0x8b0 fs/block_dev.c:1618 blkdev_get_by_path+0x8e/0xf0 fs/block_dev.c:1690 mount_bdev+0x4c/0x360 fs/super.c:1107 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.0:4038 blocked for more than 140 seconds. Not tainted 4.14.102+ #17 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28936 4038 1851 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:4026 blocked for more than 140 seconds. Not tainted 4.14.102+ #17 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D29088 4026 14599 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:4030 blocked for more than 140 seconds. Not tainted 4.14.102+ #17 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D28248 4030 14600 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.3:4031 blocked for more than 140 seconds. Not tainted 4.14.102+ #17 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D26992 4031 13948 0x00000000 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_clr_fd+0x828/0xac0 drivers/block/loop.c:1068 lo_ioctl+0x813/0x1970 drivers/block/loop.c:1414 __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:4042 blocked for more than 140 seconds. Not tainted 4.14.102+ #17 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D29152 4042 8427 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 2 locks held by getty/1759: #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 2 locks held by syz-executor.2/13940: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_ctl_mutex){+.+.}, at: [] lo_open+0x19/0xb0 drivers/block/loop.c:1623 2 locks held by syz-executor.3/13948: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_ctl_mutex){+.+.}, at: [] lo_open+0x19/0xb0 drivers/block/loop.c:1623 2 locks held by syz-executor.4/13950: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_ctl_mutex){+.+.}, at: [] lo_open+0x19/0xb0 drivers/block/loop.c:1623 1 lock held by syz-executor.0/3977: #0: (&bdev->bd_mutex){+.+.}, at: [] blkdev_put+0x27/0x4c0 fs/block_dev.c:1814 1 lock held by syz-executor.0/3994: #0: (&bdev->bd_mutex){+.+.}, at: [] blkdev_get+0x48f/0x8b0 fs/block_dev.c:1618 1 lock held by syz-executor.0/4038: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 1 lock held by blkid/4026: #0: (loop_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x83/0x1970 drivers/block/loop.c:1404 2 locks held by blkid/4030: #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.3/4031: #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 blkid/4042: #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 4.14.102+ #17 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 0xffffffff8c4420d2