CVE-2025-21897 sched_ext: Fix pick_task_scx() picking non-queued tasks when it's called without balance()

In the Linux kernel, the following vulnerability has been resolved: schedext: Fix picktaskscx picking non-queued tasks when it's called without balance a6250aa251ea "schedext: Handle cases where picktaskscx is called without preceding balancescx" added a workaround to handle the cases where...

CVE-2025-21897

CVE-2025-21897: Linux kernel sched_ext vulnerability where pick_task_scx() could return non-queued tasks if balance() wasn’t called. The fix adds a workaround to emulate SCX_RQ_BAL_KEEP only when preceding balance_scx() is missing, and corrects the prior test that used @prev to decide if a task w...

CVE-2024-57891 sched_ext: Fix invalid irq restore in scx_ops_bypass()

In the Linux kernel, the following vulnerability has been resolved: schedext: Fix invalid irq restore in scxopsbypass While adding outer irqsave/restore locking, 0e7ffff1b811 "scx: Fix raciness in scxopsbypass" forgot to convert an inner rqunlockirqrestore to rqunlock which could re-enable IRQ...