CVE-2025-21972

net: mctp: unshare packets when reassembling

MEDIUM
5.5
CVSS Score
Published: April 1, 2025 at 03:47 PM UTC
Updated: October 30, 2026 at 01:17 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.3%

Description

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

5.15 ≤ v < 6.12.206.13 ≤ v < 6.13.84a992bbd365094730a31bae1e12a6ca695336d576.146.14 rc16.14 rc26.14 rc36.14 rc46.14 rc56.14 rc6
Vendor states this is fixed in 5c47d5bfa7b096cf8890afac32141c578583f8e0 (fixed)
Vendor states this is fixed in f44fff3d3c6cd67b6f348b821d73c4d6888c7a6e (fixed)
Vendor states this is fixed in f5d83cf0eeb90fade4d5c4d17d24b8bee9ceeecc (fixed)
Vendor states this is fixed in 5.15 (unaffected)
Vendor states this is fixed in 6.12.20 (unaffected)
Vendor states this is fixed in 6.13.8 (unaffected)
Vendor states this is fixed in 6.14 (unaffected)
Vendor states this is fixed in 6.6.160 (unaffected)

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-401

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