Linux Kernel Memory Management Issue in Meta Fleet

CVE-2026-89753

What is CVE-2026-89753?

A memory management issue in the Linux kernel has been identified, leading to stalls in RCU-tasks during the reclaim process. This vulnerability specifically affects the shrink_lruvec function, where an inadequate reporting of quiescent states could result in a reclaiming task becoming unresponsive. The problem arises as the scan loop in shrink_lruvec only invokes cond_resched(), which does not effectively signal a quiescent state on PREEMPTION-enabled kernels. As a result, tasks could become holdouts, affecting overall system performance. A proposed mitigation involves upgrading to the cond_resched_tasks_rcu_qs() function, enabling proper tracking of task states.

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