Use After Free Affecting kernel-64k-debug-modules-internal package, versions *


Severity

Recommended
low

Based on CentOS security rating.

Threat Intelligence

EPSS
0.04% (11th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications

Snyk Learn

Learn about Use After Free vulnerabilities in an interactive lesson.

Start learning
  • Snyk IDSNYK-CENTOS9-KERNEL64KDEBUGMODULESINTERNAL-12884433
  • published18 Sept 2025
  • disclosed17 Sept 2025

Introduced: 17 Sep 2025

CVE-2023-53338  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

There is no fixed version for Centos:9 kernel-64k-debug-modules-internal.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-64k-debug-modules-internal package and not the kernel-64k-debug-modules-internal package as distributed by Centos. See How to fix? for Centos:9 relevant fixed versions and status.

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

lwt: Fix return values of BPF xmit ops

BPF encap ops can return different types of positive values, such like NET_RX_DROP, NET_XMIT_CN, NETDEV_TX_BUSY, and so on, from function skb_do_redirect and bpf_lwt_xmit_reroute. At the xmit hook, such return values would be treated implicitly as LWTUNNEL_XMIT_CONTINUE in ip(6)_finish_output2. When this happens, skbs that have been freed would continue to the neighbor subsystem, causing use-after-free bug and kernel crashes.

To fix the incorrect behavior, skb_do_redirect return values can be simply discarded, the same as tc-egress behavior. On the other hand, bpf_lwt_xmit_reroute returns useful errors to local senders, e.g. PMTU information. Thus convert its return values to avoid the conflict with LWTUNNEL_XMIT_CONTINUE.

CVSS Base Scores

version 3.1