CVE-2025-21972
MEDIUMCVSS VectorNVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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3DescriptionNVD
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. This avoids incorrect reassembly when packets are cloned, and prevents a memory leak due to circular references between fragments and their skb_shared_info.
The upcoming MCTP-over-USB driver uses skb_clone which can trigger the problem - other MCTP drivers don't share SKBs.
A kunit test is added to reproduce the issue.
AnalysisAI
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. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. This Memory Leak vulnerability could allow attackers to exhaust available memory leading to denial of service.
Technical ContextAI
This vulnerability is classified as Memory Leak (CWE-401), which allows attackers to exhaust available memory leading to denial of service. 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. This avoids incorrect reassembly when packets are cloned, and prevents a memory leak due to circular references between fragments and their skb_shared_info. The upcoming MCTP-over-USB driver uses skb_clone which can trigger the problem - other MCTP drivers don't share SKBs. A kunit test is added to reproduce the issue. Affected products include: Linux Linux Kernel.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Ensure all allocated memory is properly freed. Use RAII patterns or garbage-collected languages.
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