INFO: task syz-executor.0:1838 blocked for more than 140 seconds. Not tainted 4.14.123+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D25640 1838 1 0x00000004 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_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+0x460/0x1a30 drivers/block/loop.c:1414 INFO: task syz-executor.1:1841 blocked for more than 140 seconds. Not tainted 4.14.123+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D25160 1841 1 0x00000004 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_open+0x19/0xb0 drivers/block/loop.c:1623 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xdf0 fs/open.c:770 vfs_open+0x105/0x230 fs/open.c:884 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:1077 do_syscall_64+0x19b/0x510 arch/x86/entry/common.c:292 INFO: task syz-executor.3:1842 blocked for more than 140 seconds. Not tainted 4.14.123+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D24576 1842 1 0x00000004 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_open+0x19/0xb0 drivers/block/loop.c:1623 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xdf0 fs/open.c:770 vfs_open+0x105/0x230 fs/open.c:884 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:1077 do_syscall_64+0x19b/0x510 arch/x86/entry/common.c:292 INFO: task syz-executor.4:1860 blocked for more than 140 seconds. Not tainted 4.14.123+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D25384 1860 1 0x00000004 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_open+0x19/0xb0 drivers/block/loop.c:1623 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xdf0 fs/open.c:770 vfs_open+0x105/0x230 fs/open.c:884 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:1077 do_syscall_64+0x19b/0x510 arch/x86/entry/common.c:292 INFO: task syz-executor.2:2989 blocked for more than 140 seconds. Not tainted 4.14.123+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D25640 2989 1 0x00000004 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_open+0x19/0xb0 drivers/block/loop.c:1623 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xdf0 fs/open.c:770 vfs_open+0x105/0x230 fs/open.c:884 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:1077 do_syscall_64+0x19b/0x510 arch/x86/entry/common.c:292 INFO: task syz-executor.5:6386 blocked for more than 140 seconds. Not tainted 4.14.123+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28312 6386 5872 0x00000004 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 loop_control_ioctl+0x183/0x300 drivers/block/loop.c:1996 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/0x510 arch/x86/entry/common.c:292 INFO: task syz-executor.5:6395 blocked for more than 140 seconds. Not tainted 4.14.123+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D27968 6395 5872 0x00000004 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 loop_control_ioctl+0x71/0x300 drivers/block/loop.c:1982 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/0x510 arch/x86/entry/common.c:292 INFO: task syz-executor.5:6402 blocked for more than 140 seconds. Not tainted 4.14.123+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D29232 6402 5872 0x00000004 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 loop_control_ioctl+0x71/0x300 drivers/block/loop.c:1982 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/0x510 arch/x86/entry/common.c:292 INFO: task blkid:6391 blocked for more than 140 seconds. Not tainted 4.14.123+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D28608 6391 286 0x00000004 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_open+0x19/0xb0 drivers/block/loop.c:1623 __blkdev_get+0x963/0xf90 fs/block_dev.c:1537 __blkdev_get+0x6d6/0xf90 fs/block_dev.c:1517 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xdf0 fs/open.c:770 vfs_open+0x105/0x230 fs/open.c:884 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:1077 do_syscall_64+0x19b/0x510 arch/x86/entry/common.c:292 Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: (tasklist_lock){.+.+}, at: [<0000000081c673d9>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4541 1 lock held by rsyslogd/1628: #0: (&f->f_pos_lock){+.+.}, at: [<0000000054b78383>] __fdget_pos+0xa6/0xc0 fs/file.c:769 2 locks held by getty/1756: #0: (&tty->ldisc_sem){++++}, at: [<00000000d6f3d257>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000776a66a4>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.0/1838: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000abf9d48f>] lo_ioctl+0x86/0x1a30 drivers/block/loop.c:1404 #1: (&bdev->bd_mutex){+.+.}, at: [<00000000da38e9dc>] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 2 locks held by syz-executor.1/1841: #0: (&bdev->bd_mutex){+.+.}, at: [<000000008f04bde4>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000e57534d5>] lo_open+0x19/0xb0 drivers/block/loop.c:1623 2 locks held by syz-executor.3/1842: #0: (&bdev->bd_mutex){+.+.}, at: [<000000008f04bde4>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000e57534d5>] lo_open+0x19/0xb0 drivers/block/loop.c:1623 2 locks held by syz-executor.4/1860: #0: (&bdev->bd_mutex){+.+.}, at: [<000000008f04bde4>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000e57534d5>] lo_open+0x19/0xb0 drivers/block/loop.c:1623 2 locks held by syz-executor.2/2989: #0: (&bdev->bd_mutex){+.+.}, at: [<000000008f04bde4>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000e57534d5>] lo_open+0x19/0xb0 drivers/block/loop.c:1623 2 locks held by syz-executor.5/6386: #0: (loop_index_mutex){+.+.}, at: [<00000000a6f651db>] loop_control_ioctl+0x71/0x300 drivers/block/loop.c:1982 #1: (&lo->lo_ctl_mutex#2){+.+.}, at: [<000000002789a81a>] loop_control_ioctl+0x183/0x300 drivers/block/loop.c:1996 1 lock held by syz-executor.5/6395: #0: (loop_index_mutex){+.+.}, at: [<00000000a6f651db>] loop_control_ioctl+0x71/0x300 drivers/block/loop.c:1982 1 lock held by syz-executor.5/6402: #0: (loop_index_mutex){+.+.}, at: [<00000000a6f651db>] loop_control_ioctl+0x71/0x300 drivers/block/loop.c:1982 3 locks held by blkid/6391: #0: (&bdev->bd_mutex){+.+.}, at: [<000000008f04bde4>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (&bdev->bd_mutex/1){+.+.}, at: [<000000008f04bde4>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #2: (loop_index_mutex){+.+.}, at: [<00000000e57534d5>] lo_open+0x19/0xb0 drivers/block/loop.c:1623 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 23 Comm: khungtaskd Not tainted 4.14.123+ #2 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: 0 Comm: swapper/1 Not tainted 4.14.123+ #2 task: 000000001caeeff3 task.stack: 00000000c50e521d RIP: 0010:arch_local_save_flags arch/x86/include/asm/paravirt.h:773 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/paravirt.h:795 [inline] RIP: 0010:lock_is_held_type+0x55/0x150 kernel/locking/lockdep.c:4025 RSP: 0018:ffff8881daa87c70 EFLAGS: 00000246 RAX: 0000000000000246 RBX: ffff8881daa6af00 RCX: 1ffffffff34427a8 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff8881daa6b72c RBP: ffffffff9a0d3be0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881dbb2a240 R13: 000000000002a240 R14: dffffc0000000000 R15: ffff8881daa6af00 FS: 0000000000000000(0000) GS:ffff8881dbb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000002196000 CR3: 000000004f226006 CR4: 00000000001606a0 Call Trace: lock_is_held include/linux/lockdep.h:437 [inline] schedule_debug kernel/sched/core.c:3268 [inline] __schedule+0xd96/0x1f30 kernel/sched/core.c:3371 schedule_idle+0x58/0x80 kernel/sched/core.c:3525 do_idle+0x22a/0x390 kernel/sched/idle.c:292 cpu_startup_entry+0xc6/0xd0 kernel/sched/idle.c:374 start_secondary+0x3a8/0x4b0 arch/x86/kernel/smpboot.c:272 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 Code: ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 d9 00 00 00 8b 83 2c 08 00 00 85 c0 0f 85 b9 00 00 00 9c 58 <0f> 1f 44 00 00 48 89 c3 fa 66 0f 1f 44 00 00 65 4c 8b 24 25 c0