CVE-2023-52924 Affecting kernel-rt-core package, versions *


Severity

Recommended
low

Based on Red Hat Enterprise Linux security rating.

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  • Snyk IDSNYK-RHEL8-KERNELRTCORE-8703752
  • published8 Feb 2025
  • disclosed5 Feb 2025

Introduced: 5 Feb 2025

NewCVE-2023-52924  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:8 kernel-rt-core.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-rt-core package and not the kernel-rt-core package as distributed by RHEL. See How to fix? for RHEL:8 relevant fixed versions and status.

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

netfilter: nf_tables: don't skip expired elements during walk

There is an asymmetry between commit/abort and preparation phase if the following conditions are met:

  1. set is a verdict map ("1.2.3.4 : jump foo")
  2. timeouts are enabled

In this case, following sequence is problematic:

  1. element E in set S refers to chain C
  2. userspace requests removal of set S
  3. kernel does a set walk to decrement chain->use count for all elements from preparation phase
  4. kernel does another set walk to remove elements from the commit phase (or another walk to do a chain->use increment for all elements from abort phase)

If E has already expired in 1), it will be ignored during list walk, so its use count won't have been changed.

Then, when set is culled, ->destroy callback will zap the element via nf_tables_set_elem_destroy(), but this function is only safe for elements that have been deactivated earlier from the preparation phase: lack of earlier deactivate removes the element but leaks the chain use count, which results in a WARN splat when the chain gets removed later, plus a leak of the nft_chain structure.

Update pipapo_get() not to skip expired elements, otherwise flush command reports bogus ENOENT errors.

CVSS Scores

version 3.1