CVE-2025-21768

net: ipv6: fix dst ref loops in rpl, seg6 and ioam6 lwtunnels

MEDIUM
5.5
CVSS Score
Published: February 27, 2025 at 02:18 AM UTC
Updated: October 21, 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: ipv6: fix dst ref loops in rpl, seg6 and ioam6 lwtunnels Some lwtunnels have a dst cache for post-transformation dst. If the packet destination did not change we may end up recording a reference to the lwtunnel in its own cache, and the lwtunnel state will never be freed. Discovered by the ioam6.sh test, kmemleak was recently fixed to catch per-cpu memory leaks. I'm not sure if rpl and seg6 can actually hit this, but in principle I don't see why not.

Affected

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

4.10 ≤ v < 6.12.166.13 ≤ v < 6.13.44.106.146.14 rc16c8702c60b88651072460f3f4026c7dfe2521d12
Vendor states this is fixed in 4c0f200c7d06fedddde82209c099014d63f4a6c0 (fixed)
Vendor states this is fixed in 5ab11a4e219e93b8b31a27f8ec98d42afadd8b7a (fixed)
Vendor states this is fixed in 92191dd1073088753821b862b791dcc83e558e07 (fixed)
Vendor states this is fixed in 4.10 (unaffected)
Vendor states this is fixed in 6.12.16 (unaffected)
Vendor states this is fixed in 6.13.4 (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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