CVE-2026-89519

In the Linux kernel, the following vulnerability has been resolved:

sched ext: Replace SCX RQ BAL KEEP with a dispatch verdict return

SCX RQ BAL KEEP tells the pick to keep running the previous task, a leftover from when balancing and picking were separate operations. An rq-level flag only works while dispatches and picks pair up one to one, which core scheduling breaks: selections interleave through dispatch's lock drops and a pick can consume a stale flag, keeping a task that has since been dequeued. Fixing core scheduling support requires the decision to travel with the dispatch that made it. Make scx dispatch sched() and balance one() return an explicit verdict instead and drop the flag's plumbing from the tools autogen enum headers.

Also factor the pick-side invocation, its follow-up queueing and the post-dispatch checks out of do pick task scx() into dispatch pick(). No functional changes intended.

v2: Drop the SCX RQ BAL KEEP plumbing from the tools autogen enum headers as well (Andrea).