INFO: task syz-executor.0:4669 blocked for more than 140 seconds. Not tainted 4.14.133+ #17 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D27360 4669 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+0x595/0x13e0 /kernel/locking/mutex.c:893 lo_release+0x1b/0x1a0 /drivers/block/loop.c:1666 __blkdev_put+0x518/0x6d0 /fs/block_dev.c:1791 blkdev_close+0x86/0xb0 /fs/block_dev.c:1863 __fput+0x25e/0x710 /fs/file_table.c:210 task_work_run+0x125/0x1a0 /kernel/task_work.c:113 exit_task_work /./include/linux/task_work.h:22 [inline] do_exit+0x9cb/0x2a20 /kernel/exit.c:874 INFO: task syz-executor.5:5718 blocked for more than 140 seconds. Not tainted 4.14.133+ #17 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D25280 5718 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+0x595/0x13e0 /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/0xe20 /fs/open.c:770 vfs_open+0x105/0x230 /fs/open.c:884 do_last /fs/namei.c:3455 [inline] path_openat+0xb6c/0x2be0 /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/0x520 /arch/x86/entry/common.c:292 INFO: task syz-executor.4:7556 blocked for more than 140 seconds. Not tainted 4.14.133+ #17 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D25512 7556 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+0x595/0x13e0 /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/0xe20 /fs/open.c:770 vfs_open+0x105/0x230 /fs/open.c:884 do_last /fs/namei.c:3455 [inline] path_openat+0xb6c/0x2be0 /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/0x520 /arch/x86/entry/common.c:292 INFO: task syz-executor.0:7735 blocked for more than 140 seconds. Not tainted 4.14.133+ #17 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28096 7735 1846 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+0x595/0x13e0 /kernel/locking/mutex.c:893 blkdev_reread_part+0x1b/0x40 /block/ioctl.c:192 loop_reread_partitions+0x7f/0x90 /drivers/block/loop.c:614 loop_set_status+0xbff/0x11f0 /drivers/block/loop.c:1183 INFO: task syz-executor.0:7744 blocked for more than 140 seconds. Not tainted 4.14.133+ #17 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D29104 7744 1846 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+0x595/0x13e0 /kernel/locking/mutex.c:893 loop_control_ioctl+0x183/0x310 /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/0x520 /arch/x86/entry/common.c:292 INFO: task syz-executor.0:7755 blocked for more than 140 seconds. Not tainted 4.14.133+ #17 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28464 7755 1846 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+0x595/0x13e0 /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+0x44e/0xe20 /fs/open.c:770 vfs_open+0x105/0x230 /fs/open.c:884 do_last /fs/namei.c:3455 [inline] path_openat+0xb6c/0x2be0 /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/0x520 /arch/x86/entry/common.c:292 INFO: task blkid:7742 blocked for more than 140 seconds. Not tainted 4.14.133+ #17 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D28832 7742 2776 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+0x595/0x13e0 /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+0x97/0x8b0 /fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 /fs/block_dev.c:1770 do_dentry_open+0x44e/0xe20 /fs/open.c:770 vfs_open+0x105/0x230 /fs/open.c:884 do_last /fs/namei.c:3455 [inline] path_openat+0xb6c/0x2be0 /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/0x520 /arch/x86/entry/common.c:292 INFO: task syz-executor.1:7773 blocked for more than 140 seconds. Not tainted 4.14.133+ #17 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D26784 7773 1850 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+0x595/0x13e0 /kernel/locking/mutex.c:893 __blkdev_get+0xf3/0xf90 /fs/block_dev.c:1457 blkdev_get+0x44b/0x8b0 /fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 /fs/block_dev.c:1770 do_dentry_open+0x44e/0xe20 /fs/open.c:770 vfs_open+0x105/0x230 /fs/open.c:884 do_last /fs/namei.c:3455 [inline] path_openat+0xb6c/0x2be0 /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/0x520 /arch/x86/entry/common.c:292 INFO: task syz-executor.1:7779 blocked for more than 140 seconds. Not tainted 4.14.133+ #17 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28592 7779 1850 0x00000004 Call Trace: schedule+0x92/0x1c0 /kernel/sched/core.c:3498 bd_prepare_to_claim /fs/block_dev.c:1078 [inline] bd_start_claiming /fs/block_dev.c:1149 [inline] blkdev_get+0x3f2/0x8b0 /fs/block_dev.c:1605 blkdev_open+0x1cc/0x250 /fs/block_dev.c:1770 do_dentry_open+0x44e/0xe20 /fs/open.c:770 vfs_open+0x105/0x230 /fs/open.c:884 do_last /fs/namei.c:3455 [inline] path_openat+0xb6c/0x2be0 /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/0x520 /arch/x86/entry/common.c:292 Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: (tasklist_lock){.+.+}, at: [<00000000882bfed1>] debug_show_all_locks+0x7c/0x21a /kernel/locking/lockdep.c:4541 1 lock held by rsyslogd/1625: #0: (&f->f_pos_lock){+.+.}, at: [<00000000df110177>] __fdget_pos+0xb5/0xd0 /fs/file.c:769 2 locks held by getty/1753: #0: (&tty->ldisc_sem){++++}, at: [<000000008857e12e>] tty_ldisc_ref_wait+0x22/0x80 /drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000bdf2b1d2>] n_tty_read+0x1f7/0x1700 /drivers/tty/n_tty.c:2156 2 locks held by syz-executor.0/4669: #0: (&bdev->bd_mutex){+.+.}, at: [<0000000043383f19>] __blkdev_put+0xb1/0x6d0 /fs/block_dev.c:1778 #1: (loop_index_mutex){+.+.}, at: [<0000000064ca11b6>] lo_release+0x1b/0x1a0 /drivers/block/loop.c:1666 2 locks held by syz-executor.5/5718: #0: (&bdev->bd_mutex){+.+.}, at: [<000000009f6bcbef>] __blkdev_get+0xf3/0xf90 /fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000dec9cfb0>] lo_open+0x19/0xb0 /drivers/block/loop.c:1623 2 locks held by syz-executor.4/7556: #0: (&bdev->bd_mutex){+.+.}, at: [<000000009f6bcbef>] __blkdev_get+0xf3/0xf90 /fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000dec9cfb0>] lo_open+0x19/0xb0 /drivers/block/loop.c:1623 2 locks held by syz-executor.0/7735: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000685ce9db>] lo_ioctl+0x86/0x1a30 /drivers/block/loop.c:1404 #1: (&bdev->bd_mutex){+.+.}, at: [<00000000df8fe06c>] blkdev_reread_part+0x1b/0x40 /block/ioctl.c:192 2 locks held by syz-executor.0/7744: #0: (loop_index_mutex){+.+.}, at: [<000000008b5fe933>] loop_control_ioctl+0x71/0x310 /drivers/block/loop.c:1982 #1: (&lo->lo_ctl_mutex#2){+.+.}, at: [<00000000ce8f8e6b>] loop_control_ioctl+0x183/0x310 /drivers/block/loop.c:1996 1 lock held by syz-executor.0/7755: #0: (&bdev->bd_mutex){+.+.}, at: [<000000009f6bcbef>] __blkdev_get+0xf3/0xf90 /fs/block_dev.c:1457 2 locks held by blkid/7742: #0: (&bdev->bd_mutex){+.+.}, at: [<000000009f6bcbef>] __blkdev_get+0xf3/0xf90 /fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000dec9cfb0>] lo_open+0x19/0xb0 /drivers/block/loop.c:1623 1 lock held by syz-executor.1/7773: #0: (&bdev->bd_mutex){+.+.}, at: [<000000009f6bcbef>] __blkdev_get+0xf3/0xf90 /fs/block_dev.c:1457 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 23 Comm: khungtaskd Not tainted 4.14.133+ #17 Call Trace: __dump_stack /lib/dump_stack.c:17 [inline] dump_stack+0xca/0x134 /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 4.14.133+ #17 task: 0000000084e45044 task.stack: 00000000c9e2394c RIP: 0010:native_apic_mem_write+0x8/0x10 /./arch/x86/include/asm/apic.h:100 RSP: 0018:ffff8881daa87bd8 EFLAGS: 00000046 RAX: ffffffff8ba9c7e0 RBX: ffffffff8dca8880 RCX: 0000000000000020 RDX: 1ffffffff1b9512d RSI: 00000000471dba5f RDI: 0000000000000380 RBP: ffff8881dbb1df40 R08: ffff88821ffff05c R09: ffff88821ffff048 R10: ffff88821ffff057 R11: ffff88821ffff050 R12: 00000000471dba5f R13: 0000000000000003 R14: ffff8881dbb249c0 R15: ffff8881dbb24ff0 FS: 0000000000000000(0000) GS:ffff8881dbb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000842000 CR3: 0000000109826002 CR4: 00000000001606a0 Call Trace: apic_write /./arch/x86/include/asm/apic.h:395 [inline] lapic_next_event+0x59/0x90 /arch/x86/kernel/apic/apic.c:469 clockevents_program_event+0x1fd/0x2e0 /kernel/time/clockevents.c:339 tick_program_event+0x78/0xd0 /kernel/time/tick-oneshot.c:47 hrtimer_force_reprogram /kernel/time/hrtimer.c:603 [inline] hrtimer_force_reprogram /kernel/time/hrtimer.c:572 [inline] __remove_hrtimer+0x1f5/0x250 /kernel/time/hrtimer.c:903 remove_hrtimer /kernel/time/hrtimer.c:931 [inline] hrtimer_try_to_cancel /kernel/time/hrtimer.c:1030 [inline] hrtimer_try_to_cancel+0x261/0x560 /kernel/time/hrtimer.c:1012 hrtimer_cancel+0x1e/0x40 /kernel/time/hrtimer.c:1050 tick_nohz_restart /kernel/time/tick-sched.c:656 [inline] tick_nohz_restart_sched_tick /kernel/time/tick-sched.c:877 [inline] __tick_nohz_idle_restart_tick+0xda/0x390 /kernel/time/tick-sched.c:1159 tick_nohz_idle_exit+0x202/0x320 /kernel/time/tick-sched.c:1197 do_idle+0x212/0x390 /kernel/sched/idle.c:281 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: 83 3d fc fd db 02 01 77 02 5d c3 89 ef 5d e9 fb e5 fe ff 48 c7 c7 c0 c5 85 8e e8 a4 f6 49 00 eb df 66 90 89 ff 89 b7 00 d0 5f ff 0f 1f 80 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 53 89 fb