Critical Memory Leak Vulnerability in Linux Kernel: MCTP Packet Reassembly Issue
Summary
DEBIAN-CVE-2025-21972: In the Linux kernel, the following vulnerability has been resolved: net: mctp: unshare packets when reassembling Ensure that the frag_list used for reassembly isn't shared with other packets. Affects linux versions < 6.12.20-1. Fixed in 6.12.20-1. How to fix ↓
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Background
The Linux kernel is the core component of many operating systems, responsible for managing hardware resources and providing essential services to applications. It is known for its stability, performance, and flexibility, supporting a wide range of hardware architectures. However, vulnerabilities can arise, impacting its reliability and security. This specific vulnerability affects the MCTP (Management Component Transport Protocol) functionality within the kernel, which is crucial for communication between management components in various devices.
Vulnerability Detail
In the Linux kernel, a vulnerability has been identified related to the MCTP packet reassembly process. The issue arises when packets are cloned, leading to incorrect reassembly and potential memory leaks due to circular references between fragments and their skb_shared_info. This vulnerability could be exploited in scenarios where the upcoming MCTP-over-USB driver is used, which employs skb_clone, thereby triggering the problem. If left unaddressed, this could lead to resource exhaustion and system instability.
How To Fix
Minimum fixed version
6.12.20-1
This is the first release that contains the fix.
sudo apt-get install --only-upgrade linuxTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
Currently, no specific workarounds have been provided for this vulnerability. The best course of action is to apply the patch as soon as it becomes available.
Conclusion
The identified vulnerability in the Linux kernel related to MCTP packet reassembly poses significant risks, including memory leaks and system instability. It is crucial for users to update to the patched version 6.12.20-1 or later to mitigate these risks. Utilizing tools like Vulert can help monitor and alert for such vulnerabilities in real-time.
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FAQ
The vulnerability involves incorrect packet reassembly and potential memory leaks in the Linux kernel's MCTP functionality.
You can use Vulert, which monitors open-source vulnerabilities in real-time. Check your application against the vulnerability using the Vulert playground at Vulert Scanner.
Failure to address this vulnerability may lead to resource exhaustion and system instability, potentially affecting the performance of applications relying on the kernel.
Yes, versions prior to 6.12.20-1 are vulnerable to this issue.
Regularly update your Linux kernel to the latest version and monitor for any security advisories related to your system.
References
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