CVE-2024-50019

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> kthread: unpark only parked kthread<br /> <br /> Calling into kthread unparking unconditionally is mostly harmless when<br /> the kthread is already unparked. The wake up is then simply ignored<br /> because the target is not in TASK_PARKED state.<br /> <br /> However if the kthread is per CPU, the wake up is preceded by a call<br /> to kthread_bind() which expects the task to be inactive and in<br /> TASK_PARKED state, which obviously isn&amp;#39;t the case if it is unparked.<br /> <br /> As a result, calling kthread_stop() on an unparked per-cpu kthread<br /> triggers such a warning:<br /> <br /> WARNING: CPU: 0 PID: 11 at kernel/kthread.c:525 __kthread_bind_mask kernel/kthread.c:525<br /> <br /> kthread_stop+0x17a/0x630 kernel/kthread.c:707<br /> destroy_workqueue+0x136/0xc40 kernel/workqueue.c:5810<br /> wg_destruct+0x1e2/0x2e0 drivers/net/wireguard/device.c:257<br /> netdev_run_todo+0xe1a/0x1000 net/core/dev.c:10693<br /> default_device_exit_batch+0xa14/0xa90 net/core/dev.c:11769<br /> ops_exit_list net/core/net_namespace.c:178 [inline]<br /> cleanup_net+0x89d/0xcc0 net/core/net_namespace.c:640<br /> process_one_work kernel/workqueue.c:3231 [inline]<br /> process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312<br /> worker_thread+0x86d/0xd70 kernel/workqueue.c:3393<br /> kthread+0x2f0/0x390 kernel/kthread.c:389<br /> ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147<br /> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244<br /> <br /> <br /> Fix this with skipping unecessary unparking while stopping a kthread.