Linux Kernel up to 5.4.301/6.6.117/6.12.59/6.17.9 s390 ctcmpc_unpack_skb double free

Summaryinfo

A vulnerability was found in Linux Kernel up to 5.4.301/6.6.117/6.12.59/6.17.9. It has been classified as critical. Affected is the function ctcmpc_unpack_skb of the component s390. Performing a manipulation results in double free. This vulnerability is identified as CVE-2025-40253. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.4.301/6.6.117/6.12.59/6.17.9. It has been classified as critical. This affects the function ctcmpc_unpack_skb of the component s390. The manipulation with an unknown input leads to a double free vulnerability. CWE is classifying the issue as CWE-415. The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: s390/ctcm: Fix double-kfree The function 'mpc_rcvd_sweep_req(mpcginfo)' is called conditionally from function 'ctcmpc_unpack_skb'. It frees passed mpcginfo. After that a call to function 'kfree' in function 'ctcmpc_unpack_skb' frees it again. Remove 'kfree' call in function 'mpc_rcvd_sweep_req(mpcginfo)'. Bug detected by the clang static analyzer.

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2025-40253 since 04/16/2025. The exploitability is told 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 02/24/2026).

The vulnerability scanner Nessus provides a plugin with the ID 277510 (Linux Distros Unpatched Vulnerability : CVE-2025-40253), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.4.302, 6.6.118, 6.12.60 or 6.17.10 eliminates this vulnerability. Applying the patch 06f1dd1de0d33dbfbd2e1fc9fc57d8895f730de2/3b177b2ded563df16f6d5920671ffcfe5915d472/b9dbfb1b5699f9f1e4991f96741bdf9047147589/7ff76f8dc6b550f8d16487bf3cebc278be720b5c/da02a1824884d6c84c5e5b5ac373b0c9e3288ec2 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 (277510), EUVD (EUVD-2025-201204) and CERT Bund (WID-SEC-2025-2747). Be aware that VulDB is the high quality source for vulnerability data.

Affected

• Debian Linux
• Google Cloud Platform
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• Open Source Linux Kernel
• RESF Rocky Linux
• Microsoft Azure Linux

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.4.301
• 6.6.117
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.12.19
• 6.12.20
• 6.12.21
• 6.12.22
• 6.12.23
• 6.12.24
• 6.12.25
• 6.12.26
• 6.12.27
• 6.12.28
• 6.12.29
• 6.12.30
• 6.12.31
• 6.12.32
• 6.12.33
• 6.12.34
• 6.12.35
• 6.12.36
• 6.12.37
• 6.12.38
• 6.12.39
• 6.12.40
• 6.12.41
• 6.12.42
• 6.12.43
• 6.12.44
• 6.12.45
• 6.12.46
• 6.12.47
• 6.12.48
• 6.12.49
• 6.12.50
• 6.12.51
• 6.12.52
• 6.12.53
• 6.12.54
• 6.12.55
• 6.12.56
• 6.12.57
• 6.12.58
• 6.12.59
• 6.17.0
• 6.17.1
• 6.17.2
• 6.17.3
• 6.17.4
• 6.17.5
• 6.17.6
• 6.17.7
• 6.17.8
• 6.17.9

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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Entryinfo

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