CVE-2025-21919 sched/fair: Fix potential memory corruption in child_cfs_rq_on_list

In the Linux kernel, the following vulnerability has been resolved: sched/fair: Fix potential memory corruption in childcfsrqonlist childcfsrqonlist attempts to convert a 'prev' pointer to a cfsrq. This 'prev' pointer can originate from struct rq's leafcfsrqlist, making the conversion invalid and...