CVE-2026-43326

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> sched_ext: Fix SCX_KICK_WAIT deadlock by deferring wait to balance callback<br /> <br /> SCX_KICK_WAIT busy-waits in kick_cpus_irq_workfn() using<br /> smp_cond_load_acquire() until the target CPU&amp;#39;s kick_sync advances. Because<br /> the irq_work runs in hardirq context, the waiting CPU cannot reschedule and<br /> its own kick_sync never advances. If multiple CPUs form a wait cycle, all<br /> CPUs deadlock.<br /> <br /> Replace the busy-wait in kick_cpus_irq_workfn() with resched_curr() to<br /> force the CPU through do_pick_task_scx(), which queues a balance callback<br /> to perform the wait. The balance callback drops the rq lock and enables<br /> IRQs following the sched_core_balance() pattern, so the CPU can process<br /> IPIs while waiting. The local CPU&amp;#39;s kick_sync is advanced on entry to<br /> do_pick_task_scx() and continuously during the wait, ensuring any CPU that<br /> starts waiting for us sees the advancement and cannot form cyclic<br /> dependencies.