In the Linux kernel, the following vulnerability has been resolved: net/sched: schqfq: Fix race condition on qfqaggregate A race condition can occur when 'agg' is modified in qfqchangeagg (called during qfqenqueue) while other threads access it concurrently. For example, qfqdumpclass may trigger a NULL dereference, and qfqdeleteclass may cause a use-after-free. This patch addresses the issue by: 1. Moved qfqdestroyclass into the critical section. 2. Added schtreelock protection to qfqdumpclass and qfqdumpclassstats.