Improper Update of Reference Count Affecting perf package, versions <0:6.1.96-102.177.amzn2023


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.01% (2nd percentile)

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  • Snyk IDSNYK-AMZN2023-PERF-13555432
  • published15 Oct 2025
  • disclosed12 Jul 2024

Introduced: 12 Jul 2024

CVE-2024-40913  (opens in a new tab)
CWE-911  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 perf to version 0:6.1.96-102.177.amzn2023 or higher.
This issue was patched in ALAS2023-2025-836.

NVD Description

Note: Versions mentioned in the description apply only to the upstream perf package and not the perf 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:

cachefiles: defer exposing anon_fd until after copy_to_user() succeeds

After installing the anonymous fd, we can now see it in userland and close it. However, at this point we may not have gotten the reference count of the cache, but we will put it during colse fd, so this may cause a cache UAF.

So grab the cache reference count before fd_install(). In addition, by kernel convention, fd is taken over by the user land after fd_install(), and the kernel should not call close_fd() after that, i.e., it should call fd_install() after everything is ready, thus fd_install() is called after copy_to_user() succeeds.

CVSS Base Scores

version 3.1