https://vulnerability.circl.lu Contains only the most 10 recent entries. http://www.rssboard.org/rss-specification python-feedgen en Sun, 04 Oct 2026 21:32:10 +0000 https://vulnerability.circl.lu/vuln/cve-2026-43392 <p><strong>Affected:</strong> Linux</p> <p>In the Linux kernel, the following vulnerability has been resolved:</p> <p>sched_ext: Fix starvation of scx_enable() under fair-class saturation</p> <p>During scx_enable(), the READY -&gt; ENABLED task switching loop changes the calling thread&#39;s sched_class from fair to ext. Since fair has higher priority than ext, saturating fair-class workloads can indefinitely starve the enable thread, hanging the system. This was introduced when the enable path switched from preempt_disable() to scx_bypass() which doesn&#39;t protect against fair-class starvation. Note that the original preempt_disable() protection wasn&#39;t complete either - in partial switch modes, the calling thread could still be starved after preempt_enable() as it may have been switched to ext class.</p> <p>Fix it by offloading the enable body to a dedicated system-wide RT (SCHED_FIFO) kthread which cannot be starved by either fair or ext class tasks. scx_enable() lazily creates the kthread on first use and passes the ops pointer through a struct scx_enable_cmd containing the kthread_work, then synchronously waits for completion.</p> <p>The workfn runs on a different kthread from sch-&gt;helper (which runs disable_work), so it can safely flush disable_work on the error path without deadlock.</p> <p><strong>Affected:</strong> Linux</p> <p>In the Linux kernel, the following vulnerability has been resolved:</p> <p>sched_ext: Fix starvation of scx_enable() under fair-class saturation</p> <p>During scx_enable(), the READY -&gt; ENABLED task switching loop changes the calling thread&#39;s sched_class from fair to ext. Since fair has higher priority than ext, saturating fair-class workloads can indefinitely starve the enable thread, hanging the system. This was introduced when the enable path switched from preempt_disable() to scx_bypass() which doesn&#39;t protect against fair-class starvation. Note that the original preempt_disable() protection wasn&#39;t complete either - in partial switch modes, the calling thread could still be starved after preempt_enable() as it may have been switched to ext class.</p> <p>Fix it by offloading the enable body to a dedicated system-wide RT (SCHED_FIFO) kthread which cannot be starved by either fair or ext class tasks. scx_enable() lazily creates the kthread on first use and passes the ops pointer through a struct scx_enable_cmd containing the kthread_work, then synchronously waits for completion.</p> <p>The workfn runs on a different kthread from sch-&gt;helper (which runs disable_work), so it can safely flush disable_work on the error path without deadlock.</p> https://vulnerability.circl.lu/vuln/cve-2026-43392