In the Linux kernel, the following vulnerability has been resolved: smb: client: fix races in cifsd thread creation The cifsd demultiplex thread can run and access tcp_ses before the parent thread has finished populating tcp_ses, which the worker thread accesses locklessly. Also, the kthread_run macro may start the thread before returning the thread pointer. Because the pointer is part of the structure that the thread can access, if the kernel is preempted after the thread is spawned, but before the thread pointer is populated and the thread attempts to exit, it will sleep, waiting for a SIGKILL signal. Fix this by moving creation of the thread to after all of tcp_ses'es fields are populated, and spawning the thread last, using a split kthread_create/wake_up_process logic.
https://git.kernel.org/stable/c/ee8f811cbac56ffb738b3a73671a9e75b0f56e99
https://git.kernel.org/stable/c/e8a5cf2ff5a13fefb228f2069e29dd7d8e37185d
https://git.kernel.org/stable/c/0eee1e6cddd1d9ce14da06e0238ca8d3362dec90