Description
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).
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
4c95380701f58b8112f0b891de8d160e4199e19d to < 6f1d3bfe54430f8d54e0530a27f2ecbf8466576eaffected4c95380701f58b8112f0b891de8d160e4199e19d to < ffaab58d217581cb75353168f8812a16e10463fcaffected
Linux Linux
Default version status: affected
6.19affected0 to < 6.19unaffected7.2.4 to ≤ 7.2.*unaffected7.3 to ≤ *unaffected