Incorrect Synchronization Affecting kernel-tools-devel package, versions <1:6.1.188-233.385.amzn2023


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.18% (7th percentile)

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  • Snyk IDSNYK-AMZN2023-KERNELTOOLSDEVEL-20868987
  • published13 Oct 2026
  • disclosed11 Sept 2026

Introduced: 11 Sep 2026

CVE-2026-89753  (opens in a new tab)
CWE-821  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 kernel-tools-devel to version 1:6.1.188-233.385.amzn2023 or higher.
This issue was patched in ALAS2023-2026-3197.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-tools-devel package and not the kernel-tools-devel package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

mm/vmscan: report RCU-tasks quiescent states in shrink_lruvec()

I am seeing some rcu_tasks stalls in the Meta fleet during reclaim.

INFO: rcu_tasks detected stalls on tasks: 0000000088620d09: .. nvcsw: 6735/6735 holdout: 1 idle_cpu: -1/8 task:GlobalCPUThread state:R running task pid:2552016 tgid:2524552 Call Trace: shrink_lruvec mem_cgroup_iter shrink_node do_try_to_free_pages try_to_free_pages __alloc_frozen_pages_noprof alloc_pages_noprof pte_alloc_one __pte_alloc handle_mm_fault

Nothing promises direct reclaim returns in bounded time, and the scan loop in shrink_lruvec() only calls cond_resched(), which is a no-op on PREEMPTION kernels. Involuntary preemption is not a Tasks-RCU quiescent state, so the reclaiming task never reports one and becomes a holdout.

Upgrade it to cond_resched_tasks_rcu_qs(), which reports a quiescent state even when cond_resched() does nothing.

PS: This has been discussed in [1]

CVSS Base Scores

version 3.1