INFO: task kworker/1:2:802 blocked for more than 143 seconds. Not tainted 6.12.0-rc3-syzkaller-00051-g07b887f8236e #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:2 state:D stack:21216 pid:802 tgid:802 ppid:2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x105f/0x34b0 kernel/sched/core.c:6682 __schedule_loop kernel/sched/core.c:6759 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6831 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x5b8/0x9c0 kernel/locking/mutex.c:752 usb_lock_port drivers/usb/core/hub.c:3206 [inline] hub_event+0x5c4/0x4f40 drivers/usb/core/hub.c:5902 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 INFO: task kworker/1:6:4964 blocked for more than 143 seconds. Not tainted 6.12.0-rc3-syzkaller-00051-g07b887f8236e #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:6 state:D stack:21328 pid:4964 tgid:4964 ppid:2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x105f/0x34b0 kernel/sched/core.c:6682 __schedule_loop kernel/sched/core.c:6759 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6831 rwsem_down_write_slowpath+0x539/0x12a0 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write+0x1d8/0x200 kernel/locking/rwsem.c:1578 usb_register_dev+0x11c/0x550 drivers/usb/core/file.c:134 usbtmc_probe+0xdbf/0x1b10 drivers/usb/class/usbtmc.c:2461 usb_probe_interface+0x309/0x9d0 drivers/usb/core/driver.c:399 call_driver_probe drivers/base/dd.c:579 [inline] really_probe+0x23e/0xa90 drivers/base/dd.c:658 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:800 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:830 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:958 bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:459 __device_attach+0x1e8/0x4b0 drivers/base/dd.c:1030 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:534 device_add+0x114b/0x1a70 drivers/base/core.c:3675 usb_set_configuration+0x10cb/0x1c50 drivers/usb/core/message.c:2210 usb_generic_driver_probe+0xb1/0x110 drivers/usb/core/generic.c:254 usb_probe_device+0xec/0x3e0 drivers/usb/core/driver.c:294 call_driver_probe drivers/base/dd.c:579 [inline] really_probe+0x23e/0xa90 drivers/base/dd.c:658 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:800 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:830 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:958 bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:459 __device_attach+0x1e8/0x4b0 drivers/base/dd.c:1030 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:534 device_add+0x114b/0x1a70 drivers/base/core.c:3675 usb_new_device+0xd90/0x1a10 drivers/usb/core/hub.c:2651 hub_port_connect drivers/usb/core/hub.c:5521 [inline] hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] port_event drivers/usb/core/hub.c:5821 [inline] hub_event+0x2e58/0x4f40 drivers/usb/core/hub.c:5903 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 INFO: task syz.0.4120:27308 blocked for more than 144 seconds. Not tainted 6.12.0-rc3-syzkaller-00051-g07b887f8236e #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.4120 state:D stack:25840 pid:27308 tgid:27307 ppid:25962 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x105f/0x34b0 kernel/sched/core.c:6682 __schedule_loop kernel/sched/core.c:6759 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6774 rpm_resume+0x5a8/0x1330 drivers/base/power/runtime.c:834 rpm_resume+0x750/0x1330 drivers/base/power/runtime.c:892 __pm_runtime_resume+0xb6/0x170 drivers/base/power/runtime.c:1172 pm_runtime_resume_and_get include/linux/pm_runtime.h:430 [inline] usb_autopm_get_interface+0x20/0xe0 drivers/usb/core/driver.c:1833 wdm_open+0x24a/0x630 drivers/usb/class/cdc-wdm.c:730 usb_open+0x186/0x220 drivers/usb/core/file.c:47 chrdev_open+0x237/0x6a0 fs/char_dev.c:414 do_dentry_open+0x6cb/0x1390 fs/open.c:958 vfs_open+0x82/0x3f0 fs/open.c:1088 do_open fs/namei.c:3774 [inline] path_openat+0x1e6a/0x2d60 fs/namei.c:3933 do_filp_open+0x1dc/0x430 fs/namei.c:3960 do_sys_openat2+0x17a/0x1e0 fs/open.c:1415 do_sys_open fs/open.c:1430 [inline] __do_sys_openat fs/open.c:1446 [inline] __se_sys_openat fs/open.c:1441 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1441 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa50b2ec990 RSP: 002b:00007fa509f66b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fa50b2ec990 RDX: 0000000000000002 RSI: 00007fa509f66c10 RDI: 00000000ffffff9c RBP: 00007fa509f66c10 R08: 0000000000000000 R09: 00007fa509f66987 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa50b4a5f80 R15: 00007ffe6793b6a8 INFO: task syz.1.4124:27328 blocked for more than 144 seconds. Not tainted 6.12.0-rc3-syzkaller-00051-g07b887f8236e #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.4124 state:D stack:28320 pid:27328 tgid:27321 ppid:25974 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x105f/0x34b0 kernel/sched/core.c:6682 __schedule_loop kernel/sched/core.c:6759 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6831 rwsem_down_read_slowpath+0x61e/0xb20 kernel/locking/rwsem.c:1084 __down_read_common kernel/locking/rwsem.c:1248 [inline] __down_read kernel/locking/rwsem.c:1261 [inline] down_read+0x124/0x330 kernel/locking/rwsem.c:1526 usb_open+0x23/0x220 drivers/usb/core/file.c:38 chrdev_open+0x237/0x6a0 fs/char_dev.c:414 do_dentry_open+0x6cb/0x1390 fs/open.c:958 vfs_open+0x82/0x3f0 fs/open.c:1088 do_open fs/namei.c:3774 [inline] path_openat+0x1e6a/0x2d60 fs/namei.c:3933 do_filp_open+0x1dc/0x430 fs/namei.c:3960 do_sys_openat2+0x17a/0x1e0 fs/open.c:1415 do_sys_open fs/open.c:1430 [inline] __do_sys_openat fs/open.c:1446 [inline] __se_sys_openat fs/open.c:1441 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1441 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb7eae4c990 RSP: 002b:00007fb7e9a7eb70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fb7eae4c990 RDX: 0000000000000002 RSI: 00007fb7e9a7ec10 RDI: 00000000ffffff9c RBP: 00007fb7e9a7ec10 R08: 0000000000000000 R09: 00007fb7e9a7e987 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb7eb006130 R15: 00007fff948b2118 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff88ebb100 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff88ebb100 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff88ebb100 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6720 4 locks held by kworker/1:2/802: #0: ffff888105efb148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc90001bbfd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff8881093d8190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #2: ffff8881093d8190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5849 #3: ffff8881093db508 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3206 [inline] #3: ffff8881093db508 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x5c4/0x4f40 drivers/usb/core/hub.c:5902 2 locks held by getty/2607: #0: ffff888113c180a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000432f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 6 locks held by kworker/0:3/4929: #0: ffff888105efb148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc9000250fd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff88810978f190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #2: ffff88810978f190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5849 #3: ffff8881207cd190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #3: ffff8881207cd190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #4: ffff88810e3f3160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #4: ffff88810e3f3160 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #5: ffffffff899dae90 (minor_rwsem){++++}-{3:3}, at: usb_register_dev+0x11c/0x550 drivers/usb/core/file.c:134 6 locks held by kworker/1:5/4956: #0: ffff888105efb148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc9000258fd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff888109727190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #2: ffff888109727190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5849 #3: ffff888139024190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #3: ffff888139024190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #4: ffff888129a8c160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #4: ffff888129a8c160 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #5: ffffffff899dae90 (minor_rwsem){++++}-{3:3}, at: usb_register_dev+0x11c/0x550 drivers/usb/core/file.c:134 6 locks held by kworker/1:6/4964: #0: ffff888105efb148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc9000240fd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff888109385190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #2: ffff888109385190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5849 #3: ffff88810136d190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #3: ffff88810136d190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #4: ffff88810136a160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #4: ffff88810136a160 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #5: ffffffff899dae90 (minor_rwsem){++++}-{3:3}, at: usb_register_dev+0x11c/0x550 drivers/usb/core/file.c:134 4 locks held by udevd/7321: #0: ffff888136da6540 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff8881321f2c88 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff888112cbff08 (kn->active#19){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff888139024190 (&dev->mutex){....}-{3:3}, at: device_lock_interruptible include/linux/device.h:1019 [inline] #3: ffff888139024190 (&dev->mutex){....}-{3:3}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 4 locks held by udevd/7584: #0: ffff888136db72f0 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff8881126a0488 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff888138719878 (kn->active#19){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff8881207cd190 (&dev->mutex){....}-{3:3}, at: device_lock_interruptible include/linux/device.h:1019 [inline] #3: ffff8881207cd190 (&dev->mutex){....}-{3:3}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 3 locks held by kworker/0:1/19696: #0: ffff888100eed548 ((wq_completion)pm){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc900036b7d80 ((work_completion)(&dev->power.work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff8881093db508 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3206 [inline] #2: ffff8881093db508 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_port_suspend+0x255/0xf10 drivers/usb/core/hub.c:3463 5 locks held by kworker/u8:4/25986: #0: ffff888100abb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc90004e27d80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffffffff8a18ca50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xbb/0xb40 net/core/net_namespace.c:580 #3: ffffffff8a1a2368 (rtnl_mutex){+.+.}-{3:3}, at: cleanup_net+0x503/0xb40 net/core/net_namespace.c:616 #4: ffffffff88ec69f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x282/0x3b0 kernel/rcu/tree_exp.h:297 2 locks held by syz.0.4120/27308: #0: ffffffff899dae90 (minor_rwsem){++++}-{3:3}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38 #1: ffffffff89a96908 (wdm_mutex){+.+.}-{3:3}, at: wdm_open+0x5d/0x630 drivers/usb/class/cdc-wdm.c:715 1 lock held by syz.1.4124/27328: #0: ffffffff899dae90 (minor_rwsem){++++}-{3:3}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38 1 lock held by syz.4.4133/27350: #0: ffffffff899dae90 (minor_rwsem){++++}-{3:3}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38 1 lock held by syz.2.4137/27360: #0: ffffffff899dae90 (minor_rwsem){++++}-{3:3}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38 1 lock held by syz.3.4157/28873: #0: ffffffff899dae90 (minor_rwsem){++++}-{3:3}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38 1 lock held by syz.2.4183/29297: #0: ffffffff899dae90 (minor_rwsem){++++}-{3:3}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38 1 lock held by syz.0.4189/29346: #0: ffffffff899dae90 (minor_rwsem){++++}-{3:3}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38 1 lock held by syz.4.4193/29476: #0: ffffffff899dae90 (minor_rwsem){++++}-{3:3}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38 1 lock held by syz.4.4193/29505: #0: ffffffff899dae90 (minor_rwsem){++++}-{3:3}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38 1 lock held by syz.3.4196/29784: #0: ffffffff899dae90 (minor_rwsem){++++}-{3:3}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38 1 lock held by syz.0.4216/31393: #0: ffffffff899dae90 (minor_rwsem){++++}-{3:3}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38 1 lock held by syz.2.4219/31521: #0: ffffffff899dae90 (minor_rwsem){++++}-{3:3}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38 1 lock held by syz.2.4219/31532: #0: ffffffff899dae90 (minor_rwsem){++++}-{3:3}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38 1 lock held by syz.4.4225/31677: #0: ffffffff899dae90 (minor_rwsem){++++}-{3:3}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38 1 lock held by syz.3.4229/31690: #0: ffffffff899dae90 (minor_rwsem){++++}-{3:3}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38 1 lock held by syz.0.4290/1210: #0: ffffffff899dae90 (minor_rwsem){++++}-{3:3}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38 1 lock held by syz.2.4295/1226: #0: ffffffff899dae90 (minor_rwsem){++++}-{3:3}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38 1 lock held by syz.4.4306/1261: #0: ffffffff899dae90 (minor_rwsem){++++}-{3:3}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38 1 lock held by syz.3.4313/1279: #0: ffffffff899dae90 (minor_rwsem){++++}-{3:3}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc3-syzkaller-00051-g07b887f8236e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xf0c/0x1240 kernel/hung_task.c:379 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:111