Use After Free Affecting kernel-tools package, versions <0:5.14.0-687.25.1.el9_8


Severity

Recommended
high

Based on Rocky Linux security rating.

Threat Intelligence

Exploit Maturity
Proof of Concept
EPSS
0.13% (3rd percentile)

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  • Snyk IDSNYK-ROCKY9-KERNELTOOLS-17976091
  • published15 Jul 2026
  • disclosed21 May 2026

Introduced: 21 May 2026

CVE-2026-43499  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Rocky-Linux:9 kernel-tools to version 0:5.14.0-687.25.1.el9_8 or higher.
This issue was patched in RLSA-2026:38491.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-tools package and not the kernel-tools package as distributed by Rocky-Linux. See How to fix? for Rocky-Linux:9 relevant fixed versions and status.

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

rtmutex: Use waiter::task instead of current in remove_waiter()

remove_waiter() is used by the slowlock paths, but it is also used for proxy-lock rollback in rt_mutex_start_proxy_lock() when invoked from futex_requeue().

In the latter case waiter::task is not current, but remove_waiter() operates on current for the dequeue operation. That results in several problems:

  1. the rbtree dequeue happens without waiter::task::pi_lock being held

  2. the waiter task's pi_blocked_on state is not cleared, which leaves a dangling pointer primed for UAF around.

  3. rt_mutex_adjust_prio_chain() operates on the wrong top priority waiter task

Use waiter::task instead of current in all related operations in remove_waiter() to cure those problems.

[ tglx: Fixup rt_mutex_adjust_prio_chain(), add a comment and amend the changelog ]

CVSS Base Scores

version 3.1