INFO: task syz-executor.5:1854 blocked for more than 140 seconds. Not tainted 4.14.153+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D25008 1854 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __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:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x413f90 RSP: 002b:00007ffcff9a69f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000028d2d RCX: 0000000000413f90 RDX: 00007ffcff9a6a8a RSI: 0000000000000002 RDI: 00007ffcff9a6a80 RBP: 0000000000000118 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffcff9a6a30 R14: 0000000000028b83 R15: 00007ffcff9a6a40 INFO: task syz-executor.1:4727 blocked for more than 140 seconds. Not tainted 4.14.153+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D25312 4727 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __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:1624 __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:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x413f90 RSP: 002b:00007ffced793238 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000028e78 RCX: 0000000000413f90 RDX: 00007ffced7932ca RSI: 0000000000000002 RDI: 00007ffced7932c0 RBP: 0000000000000069 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffced793270 R14: 0000000000028878 R15: 00007ffced793280 INFO: task syz-executor.2:5301 blocked for more than 140 seconds. Not tainted 4.14.153+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D26544 5301 1849 0x80000002 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __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:1667 __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:875 do_group_exit+0x100/0x2e0 kernel/exit.c:978 get_signal+0x39f/0x1cc0 kernel/signal.c:2422 do_signal+0x96/0x15d0 arch/x86/kernel/signal.c:814 exit_to_usermode_loop+0x11d/0x160 arch/x86/entry/common.c:160 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x3a3/0x520 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45a219 RSP: 002b:00007f3303b7acf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000075bf28 RCX: 000000000045a219 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000075bf28 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000075bf2c R13: 00007fff931fd1bf R14: 00007f3303b7b9c0 R15: 000000000075bf2c INFO: task syz-executor.3:5439 blocked for more than 140 seconds. Not tainted 4.14.153+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D25312 5439 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __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:1624 __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:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x413f90 RSP: 002b:00007ffd5f63fdd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000028dfb RCX: 0000000000413f90 RDX: 00007ffd5f63fe6a RSI: 0000000000000002 RDI: 00007ffd5f63fe60 RBP: 0000000000000028 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd5f63fe10 R14: 0000000000028ac7 R15: 00007ffd5f63fe20 INFO: task syz-executor.4:6054 blocked for more than 140 seconds. Not tainted 4.14.153+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D27584 6054 1850 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __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:1997 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 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45a219 RSP: 002b:00007fd0f843bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a219 RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd0f843c6d4 R13: 00000000004c3c55 R14: 00000000004d7fd8 R15: 00000000ffffffff INFO: task syz-executor.0:6058 blocked for more than 140 seconds. Not tainted 4.14.153+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D27408 6058 5053 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __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:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x413fb1 RSP: 002b:00007ff5940c39f0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007ff5940c46d4 RCX: 0000000000413fb1 RDX: 00007ff5940c3baa RSI: 0000000000000002 RDI: 00007ff5940c3ba0 RBP: 0000000000000005 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000293 R12: 0000000000000005 R13: 0000000000000005 R14: 00007ff5940c46d4 R15: 00000000ffffffff INFO: task syz-executor.0:6059 blocked for more than 140 seconds. Not tainted 4.14.153+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28152 6059 5053 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __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 loop_set_status64+0xa5/0x100 drivers/block/loop.c:1301 lo_ioctl+0xd1/0x1a30 drivers/block/loop.c:1431 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x8d0/0x1870 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/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45a087 RSP: 002b:00007ff5940a29f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ff5940a36d4 RCX: 000000000045a087 RDX: 00007ff5940a2ab0 RSI: 0000000000004c04 RDI: 0000000000000006 RBP: 0000000000000005 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000202 R12: 0000000000000005 R13: 0000000000000005 R14: 0000000000000006 R15: 00000000ffffffff INFO: task blkid:6063 blocked for more than 140 seconds. Not tainted 4.14.153+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D28944 6063 5745 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __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:1624 __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:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f42c0d4c120 RSP: 002b:00007fffea99ffe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f42c0d4c120 RDX: 00007fffea9a1f34 RSI: 0000000000000000 RDI: 00007fffea9a1f34 RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000001e0e030 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005 INFO: task blkid:6065 blocked for more than 140 seconds. Not tainted 4.14.153+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D28864 6065 2930 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __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:1624 __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:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f96e6a5c120 RSP: 002b:00007ffd283a2558 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f96e6a5c120 RDX: 00007ffd283a2f34 RSI: 0000000000000000 RDI: 00007ffd283a2f34 RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000780030 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005 INFO: task blkid:6070 blocked for more than 140 seconds. Not tainted 4.14.153+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D28704 6070 3661 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __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:1624 __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:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7feafdc0f120 RSP: 002b:00007ffe5a51b7a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007feafdc0f120 RDX: 00007ffe5a51df41 RSI: 0000000000000000 RDI: 00007ffe5a51df41 RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000229f030 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005 Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: (tasklist_lock){.+.+}, at: [<0000000003cfba8c>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4544 2 locks held by getty/1759: #0: (&tty->ldisc_sem){++++}, at: [<000000008acde0cb>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000005b100fb6>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.5/1854: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000b59b23b5>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 2 locks held by syz-executor.1/4727: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000b59b23b5>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<000000006e5f2dc5>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.2/5301: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000190a11a4>] __blkdev_put+0xb1/0x6d0 fs/block_dev.c:1778 #1: (loop_index_mutex){+.+.}, at: [<000000000784d9fa>] lo_release+0x1b/0x1a0 drivers/block/loop.c:1667 2 locks held by syz-executor.3/5439: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000b59b23b5>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<000000006e5f2dc5>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.4/6054: #0: (loop_index_mutex){+.+.}, at: [<000000005747db8f>] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1983 #1: (&lo->lo_ctl_mutex#2){+.+.}, at: [<00000000a05555b5>] loop_control_ioctl+0x183/0x310 drivers/block/loop.c:1997 1 lock held by syz-executor.0/6058: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000b59b23b5>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 2 locks held by syz-executor.0/6059: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000da2bccf6>] lo_ioctl+0x86/0x1a30 drivers/block/loop.c:1404 #1: (&bdev->bd_mutex){+.+.}, at: [<00000000ed7443e4>] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 2 locks held by blkid/6063: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000b59b23b5>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<000000006e5f2dc5>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by blkid/6065: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000b59b23b5>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<000000006e5f2dc5>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by blkid/6070: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000b59b23b5>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<000000006e5f2dc5>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 1 lock held by syz-executor.2/6079: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000b59b23b5>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 23 Comm: khungtaskd Not tainted 4.14.153+ #0 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 nmi_trigger_cpumask_backtrace+0x119/0x147 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x629/0xbe0 kernel/hung_task.c:274 kthread+0x31f/0x430 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at pc 0xffffffffb22a5373