kernel: mm: multi-gen LRU: fix crash during cgroup migration

In the Linux kernel, the following vulnerability has been resolved: mm: multi-gen LRU: fix crash during cgroup migration lrugenmigratemm assumes lrugenaddmm runs prior to itself. This isn't true for the following scenario: CPU 1 CPU 2 clone cgroupcanfork cgroupprocswrite cgrouppostfork tasklock...