Linux Kernel up to 5.15.120/6.1.38/6.4.3 KVM out-of-bounds

Summaryinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 5.15.120/6.1.38/6.4.3. Affected by this vulnerability is an unknown functionality of the component KVM. This manipulation causes out-of-bounds. This vulnerability is registered as CVE-2023-53205. The attack needs to be launched locally. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.15.120/6.1.38/6.4.3. It has been declared as problematic. Affected by this vulnerability is an unknown functionality of the component KVM. The manipulation with an unknown input leads to a out-of-bounds vulnerability. The CWE definition for the vulnerability is CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: KVM: s390/diag: fix racy access of physical cpu number in diag 9c handler We do check for target CPU == -1, but this might change at the time we are going to use it. Hold the physical target CPU in a local variable to avoid out-of-bound accesses to the cpu arrays.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2023-53205 since 09/15/2025. The exploitation appears to be easy. Attacking locally is a requirement. The technical details are unknown and an exploit is not publicly available.

Upgrading to version 5.15.121, 6.1.39 or 6.4.4 eliminates this vulnerability. Applying the patch a9ccf140a2a03a0ae82be4bdfbdd17bdaea72ff5/86bfb18bad60fc468e5f112cbbd918462a8dd435/dc7e0192c470a53d847c79a2796f9ac429477a26/0bc380beb78aa352eadbc21d934dd9606fcee808 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 vulnerability database at CERT Bund (WID-SEC-2025-2053). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• IBM QRadar SIEM
• SUSE openSUSE
• Open Source Linux Kernel
• RESF Rocky Linux
• Dell Secure Connect Gateway
• F5 F5OS

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.15.120
• 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
• 6.4.0
• 6.4.1
• 6.4.2
• 6.4.3

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