NULL Pointer Dereference Affecting kernel package, versions *


Severity

Recommended
low

Based on CentOS security rating.

Threat Intelligence

EPSS
0.04% (12th 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 NULL Pointer Dereference vulnerabilities in an interactive lesson.

Start learning
  • Snyk IDSNYK-CENTOS8-KERNEL-7328147
  • published21 Jun 2024
  • disclosed19 Jun 2024

Introduced: 19 Jun 2024

CVE-2024-38605  (opens in a new tab)
CWE-476  (opens in a new tab)

How to fix?

There is no fixed version for Centos:8 kernel.

NVD Description

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

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

ALSA: core: Fix NULL module pointer assignment at card init

The commit 81033c6b584b ("ALSA: core: Warn on empty module") introduced a WARN_ON() for a NULL module pointer passed at snd_card object creation, and it also wraps the code around it with '#ifdef MODULE'. This works in most cases, but the devils are always in details. "MODULE" is defined when the target code (i.e. the sound core) is built as a module; but this doesn't mean that the caller is also built-in or not. Namely, when only the sound core is built-in (CONFIG_SND=y) while the driver is a module (CONFIG_SND_USB_AUDIO=m), the passed module pointer is ignored even if it's non-NULL, and card->module remains as NULL. This would result in the missing module reference up/down at the device open/close, leading to a race with the code execution after the module removal.

For addressing the bug, move the assignment of card->module again out of ifdef. The WARN_ON() is still wrapped with ifdef because the module can be really NULL when all sound drivers are built-in.

Note that we keep 'ifdef MODULE' for WARN_ON(), otherwise it would lead to a false-positive NULL module check. Admittedly it won't catch perfectly, i.e. no check is performed when CONFIG_SND=y. But, it's no real problem as it's only for debugging, and the condition is pretty rare.

CVSS Scores

version 3.1