Bug 2356602 (CVE-2025-21972) - CVE-2025-21972 kernel: net: mctp: unshare packets when reassembling
Summary: CVE-2025-21972 kernel: net: mctp: unshare packets when reassembling
Keywords:
Status: NEW
Alias: CVE-2025-21972
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2025-04-01 16:01 UTC by OSIDB Bzimport
Modified: 2025-04-02 04:33 UTC (History)
4 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
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Description OSIDB Bzimport 2025-04-01 16:01:56 UTC
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.


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