Linux Kernel up to 6.1.42/6.4.7 CXL Driver cxl_parse_cfmws use after free

Summaryinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.1.42/6.4.7. Affected by this issue is the function cxl_parse_cfmws of the component CXL Driver. This manipulation causes use after free. This vulnerability is registered as CVE-2023-53479. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.1.42/6.4.7. It has been declared as critical. Affected by this vulnerability is the function cxl_parse_cfmws of the component CXL Driver. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: cxl/acpi: Fix a use-after-free in cxl_parse_cfmws() KASAN and KFENCE detected an user-after-free in the CXL driver. This happens in the cxl_decoder_add() fail path. KASAN prints the following error: BUG: KASAN: slab-use-after-free in cxl_parse_cfmws (drivers/cxl/acpi.c:299) This happens in cxl_parse_cfmws(), where put_device() is called, releasing cxld, which is accessed later. Use the local variables in the dev_err() instead of pointing to the released memory. Since the dev_err() is printing a resource, change the open coded print format to use the %pr format specifier.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2023-53479 since 10/01/2025. The exploitation appears to be easy. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 01/21/2026).

The vulnerability scanner Nessus provides a plugin with the ID 269643 (Linux Distros Unpatched Vulnerability : CVE-2023-53479), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.1.43 or 6.4.8 eliminates this vulnerability. Applying the patch 748fadc08bcbdaf573b34d9784bb3dbd87441dbf/316db489647b8ddc381682597e89787eac61a278/4cf67d3cc9994a59cf77bb9c0ccf9007fe916afe is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (269643) and CERT Bund (WID-SEC-2025-2187). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

• Amazon Linux 2
• Red Hat Enterprise Linux
• SUSE Linux
• Oracle Linux
• Open Source Linux Kernel
• Dell Secure Connect Gateway

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.1.0
• 6.1.1
• 6.1.2
• 6.1.3
• 6.1.4
• 6.1.5
• 6.1.6
• 6.1.7
• 6.1.8
• 6.1.9
• 6.1.10
• 6.1.11
• 6.1.12
• 6.1.13
• 6.1.14
• 6.1.15
• 6.1.16
• 6.1.17
• 6.1.18
• 6.1.19
• 6.1.20
• 6.1.21
• 6.1.22
• 6.1.23
• 6.1.24
• 6.1.25
• 6.1.26
• 6.1.27
• 6.1.28
• 6.1.29
• 6.1.30
• 6.1.31
• 6.1.32
• 6.1.33
• 6.1.34
• 6.1.35
• 6.1.36
• 6.1.37
• 6.1.38
• 6.1.39
• 6.1.40
• 6.1.41
• 6.1.42
• 6.4.0
• 6.4.1
• 6.4.2
• 6.4.3
• 6.4.4
• 6.4.5
• 6.4.6
• 6.4.7

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Discussion