CVE-2025-21768

Summary

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.

Impact & exploitability

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products we track (1)

Recommendation

Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.

Official patch: https://git.kernel.org/stable/c/4c0f200c7d06fedddde82209c099014d63f4a6c0 ↗

Additional information

• NVD record
• https://git.kernel.org/stable/c/4c0f200c7d06fedddde82209c099014d63f4a6c0Patch
• https://git.kernel.org/stable/c/5ab11a4e219e93b8b31a27f8ec98d42afadd8b7aPatch
• https://git.kernel.org/stable/c/92191dd1073088753821b862b791dcc83e558e07Patch
• https://git.kernel.org/stable/c/26f0b472ae2a82920e38c7cf41583951046d586a
• https://git.kernel.org/stable/c/e2ef3fa31353b30bda94358fe5205c141289746d