Bluetooth: hci4 command 0x0406 tx timeout Bluetooth: hci3 command 0x0406 tx timeout Bluetooth: hci0 command 0x0406 tx timeout Bluetooth: hci2 command 0x0406 tx timeout Bluetooth: hci1 command 0x0406 tx timeout INFO: task syz-executor.5:8004 blocked for more than 140 seconds. Not tainted 4.14.288-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D25784 8004 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3489 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 __blkdev_get+0x191/0x1090 fs/block_dev.c:1455 blkdev_get+0x88/0x890 fs/block_dev.c:1611 blkdev_open+0x1cc/0x250 fs/block_dev.c:1772 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0x628/0x2970 fs/namei.c:3569 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f17f680c024 RSP: 002b:00007ffccf805e50 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffccf805f50 RCX: 00007f17f680c024 RDX: 0000000000000002 RSI: 00007ffccf805f90 RDI: 00000000ffffff9c RBP: 00007ffccf805f90 R08: 0000000000000000 R09: 00007ffccf805d60 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 00000000000270a8 R14: 000000000000000a R15: 00007ffccf805f90 INFO: task syz-executor.2:8005 blocked for more than 140 seconds. Not tainted 4.14.288-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D25840 8005 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3489 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1634 __blkdev_get+0x306/0x1090 fs/block_dev.c:1470 blkdev_get+0x88/0x890 fs/block_dev.c:1611 blkdev_open+0x1cc/0x250 fs/block_dev.c:1772 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0x628/0x2970 fs/namei.c:3569 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f07b58f9024 RSP: 002b:00007ffc8467cd00 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffc8467ce00 RCX: 00007f07b58f9024 RDX: 0000000000000002 RSI: 00007ffc8467ce40 RDI: 00000000ffffff9c RBP: 00007ffc8467ce40 R08: 0000000000000000 R09: 00007ffc8467cc10 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 0000000000027308 R14: 000000000000001e R15: 00007ffc8467ce40 INFO: task syz-executor.4:8007 blocked for more than 140 seconds. Not tainted 4.14.288-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D25632 8007 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3489 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1634 __blkdev_get+0x306/0x1090 fs/block_dev.c:1470 blkdev_get+0x88/0x890 fs/block_dev.c:1611 blkdev_open+0x1cc/0x250 fs/block_dev.c:1772 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0x628/0x2970 fs/namei.c:3569 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f012ac36024 RSP: 002b:00007ffee3003640 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffee3003740 RCX: 00007f012ac36024 RDX: 0000000000000002 RSI: 00007ffee3003780 RDI: 00000000ffffff9c RBP: 00007ffee3003780 R08: 0000000000000000 R09: 00007ffee3003550 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 0000000000027233 R14: 000000000000001e R15: 00007ffee3003780 INFO: task syz-executor.3:8009 blocked for more than 140 seconds. Not tainted 4.14.288-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D25840 8009 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3489 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1634 __blkdev_get+0x306/0x1090 fs/block_dev.c:1470 blkdev_get+0x88/0x890 fs/block_dev.c:1611 blkdev_open+0x1cc/0x250 fs/block_dev.c:1772 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0x628/0x2970 fs/namei.c:3569 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f6e95dae024 RSP: 002b:00007fff656ad370 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fff656ad470 RCX: 00007f6e95dae024 RDX: 0000000000000002 RSI: 00007fff656ad4b0 RDI: 00000000ffffff9c RBP: 00007fff656ad4b0 R08: 0000000000000000 R09: 00007fff656ad280 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 000000000002738c R14: 000000000000001e R15: 00007fff656ad4b0 INFO: task systemd-udevd:10593 blocked for more than 140 seconds. Not tainted 4.14.288-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. systemd-udevd D28712 10593 4628 0x00000304 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3489 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1634 __blkdev_get+0xa8c/0x1090 fs/block_dev.c:1537 blkdev_get+0x88/0x890 fs/block_dev.c:1611 blkdev_open+0x1cc/0x250 fs/block_dev.c:1772 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0x628/0x2970 fs/namei.c:3569 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f8be326f840 RSP: 002b:00007ffd9dcaca08 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 000055aeb5da0140 RCX: 00007f8be326f840 RDX: 000055aeb4a71fe3 RSI: 00000000000a0800 RDI: 000055aeb5d8d970 RBP: 00007ffd9dcacb80 R08: 000055aeb4a71670 R09: 0000000000000010 R10: 000055aeb4a71d0c R11: 0000000000000246 R12: 00007ffd9dcacad0 R13: 000055aeb5d9e880 R14: 0000000000000003 R15: 000000000000000e INFO: task systemd-udevd:10696 blocked for more than 140 seconds. Not tainted 4.14.288-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. systemd-udevd D28064 10696 4628 0x00000304 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3489 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1634 __blkdev_get+0x306/0x1090 fs/block_dev.c:1470 blkdev_get+0x88/0x890 fs/block_dev.c:1611 blkdev_open+0x1cc/0x250 fs/block_dev.c:1772 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0x628/0x2970 fs/namei.c:3569 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f8be326f840 RSP: 002b:00007ffd9dcac418 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 000055aeb5da17c0 RCX: 00007f8be326f840 RDX: 000055aeb4a71fe3 RSI: 00000000000a0800 RDI: 000055aeb5db9d60 RBP: 00007ffd9dcac590 R08: 000055aeb4a71670 R09: 0000000000000010 R10: 000055aeb4a71d0c R11: 0000000000000246 R12: 00007ffd9dcac4e0 R13: 000055aeb5d9b6e0 R14: 0000000000000003 R15: 000000000000000e INFO: task systemd-udevd:10715 blocked for more than 140 seconds. Not tainted 4.14.288-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. systemd-udevd D28144 10715 4628 0x00000304 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3489 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 blkdev_put+0x27/0x4c0 fs/block_dev.c:1826 blkdev_close+0x86/0xb0 fs/block_dev.c:1875 __fput+0x25f/0x7a0 fs/file_table.c:210 task_work_run+0x11f/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1ad/0x200 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f8be326f270 RSP: 002b:00007ffd9dca75c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 000000000000000f RCX: 00007f8be326f270 RDX: 00007f8be3259b58 RSI: 0000000000000000 RDI: 000000000000000f RBP: 00007f8be4129710 R08: 000055aeb5d9c370 R09: 0000000000000000 R10: 000055aeb5d9fd60 R11: 0000000000000246 R12: 0000000000000002 R13: 00007ffd9dca7628 R14: 000055aeb5d9fc20 R15: 000000000000000f INFO: task syz-executor.1:10733 blocked for more than 140 seconds. Not tainted 4.14.288-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28104 10733 8006 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3489 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 loop_reread_partitions drivers/block/loop.c:624 [inline] loop_set_status+0xeeb/0x12b0 drivers/block/loop.c:1193 loop_set_status64+0x92/0xe0 drivers/block/loop.c:1311 lo_ioctl+0x587/0x1cd0 drivers/block/loop.c:1441 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x540/0x1830 block/ioctl.c:594 block_ioctl+0xd9/0x120 fs/block_dev.c:1893 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7fb0c1828ec7 RSP: 002b:00007fb0c019ded8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fb0c019df20 RCX: 00007fb0c1828ec7 RDX: 00007fb0c019e030 RSI: 0000000000004c04 RDI: 0000000000000004 RBP: 00007fb0c18830ed R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007fb0c019e030 R13: 00007ffc32ce481f R14: 00007fb0c019e300 R15: 0000000000022000 INFO: task syz-executor.1:10745 blocked for more than 140 seconds. Not tainted 4.14.288-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D30016 10745 8006 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3489 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 loop_control_ioctl+0x181/0x3f0 drivers/block/loop.c:2007 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7fb0c1829109 RSP: 002b:00007fb0c017d168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fb0c193c030 RCX: 00007fb0c1829109 RDX: 0000000000000001 RSI: 0000000000004c81 RDI: 0000000000000005 RBP: 00007fb0c18830ed R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc32ce481f R14: 00007fb0c017d300 R15: 0000000000022000 INFO: task syz-executor.0:10736 blocked for more than 140 seconds. Not tainted 4.14.288-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28144 10736 8008 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3489 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 lo_release+0x1b/0x190 drivers/block/loop.c:1677 __blkdev_put+0x5aa/0x800 fs/block_dev.c:1803 blkdev_close+0x86/0xb0 fs/block_dev.c:1875 __fput+0x25f/0x7a0 fs/file_table.c:210 task_work_run+0x11f/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1ad/0x200 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f4b99422d4b RSP: 002b:00007f4b97de4f70 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000020000200 RCX: 00007f4b99422d4b RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000004 RBP: 00007f4b97de56b8 R08: 0000000000000000 R09: 00000000200001c0 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000005 R13: 0000000000000000 R14: 00007f4b97de4fe0 R15: 0000000020000300 Showing all locks held in the system: 1 lock held by khungtaskd/1464: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 2 locks held by agetty/7725: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e3/0x1680 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.5/8004: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x191/0x1090 fs/block_dev.c:1455 2 locks held by syz-executor.2/8005: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x191/0x1090 fs/block_dev.c:1455 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x19/0xb0 drivers/block/loop.c:1634 2 locks held by syz-executor.4/8007: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x191/0x1090 fs/block_dev.c:1455 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x19/0xb0 drivers/block/loop.c:1634 2 locks held by syz-executor.3/8009: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x191/0x1090 fs/block_dev.c:1455 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x19/0xb0 drivers/block/loop.c:1634 2 locks held by systemd-udevd/10593: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x191/0x1090 fs/block_dev.c:1455 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x19/0xb0 drivers/block/loop.c:1634 2 locks held by systemd-udevd/10696: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x191/0x1090 fs/block_dev.c:1455 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x19/0xb0 drivers/block/loop.c:1634 1 lock held by systemd-udevd/10715: #0: (&bdev->bd_mutex){+.+.}, at: [] blkdev_put+0x27/0x4c0 fs/block_dev.c:1826 2 locks held by syz-executor.1/10733: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x87/0x1cd0 drivers/block/loop.c:1414 #1: (&bdev->bd_mutex){+.+.}, at: [] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 2 locks held by syz-executor.1/10745: #0: (loop_index_mutex){+.+.}, at: [] loop_control_ioctl+0x67/0x3f0 drivers/block/loop.c:1993 #1: (&lo->lo_ctl_mutex){+.+.}, at: [] loop_control_ioctl+0x181/0x3f0 drivers/block/loop.c:2007 2 locks held by syz-executor.0/10736: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_put+0xd8/0x800 fs/block_dev.c:1790 #1: (loop_index_mutex){+.+.}, at: [] lo_release+0x1b/0x190 drivers/block/loop.c:1677 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1464 Comm: khungtaskd Not tainted 4.14.288-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x180 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+0x5b9/0xb40 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 9 Comm: rcu_preempt Not tainted 4.14.288-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 task: ffff8880b5420240 task.stack: ffff8880b5428000 RIP: 0010:get_lock_parent_ip include/linux/ftrace.h:730 [inline] RIP: 0010:preempt_latency_start kernel/sched/core.c:3088 [inline] RIP: 0010:preempt_count_add+0xaf/0x170 kernel/sched/core.c:3113 RSP: 0018:ffff8880b542fd98 EFLAGS: 00000083 RAX: 0000000000000001 RBX: ffffffff8723ef2f RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8723ef2f RBP: 0000000000000001 R08: ffffffff8b9b7300 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 R13: ffffffff88f7a400 R14: ffffffff88f7a7e0 R15: ffffffff88f7a400 FS: 0000000000000000(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcf944df000 CR3: 00000000953db000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock_irq include/linux/spinlock_api_smp.h:127 [inline] _raw_spin_lock_irq+0x3f/0x80 kernel/locking/spinlock.c:168 rcu_gp_cleanup kernel/rcu/tree.c:2141 [inline] rcu_gp_kthread+0x1050/0x1e60 kernel/rcu/tree.c:2304 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: 7e 0f b6 c0 3d f4 00 00 00 7f 60 65 8b 05 5a 5a c9 7e 25 ff ff ff 7f 39 c5 74 03 5b 5d c3 48 8b 5c 24 10 48 89 df e8 a1 da 08 00 <85> c0 75 31 65 48 8b 2c 25 c0 7f 02 00 48 8d bd 38 12 00 00 48