CVEvulnerability
CVE-2026-97472
- Status
- Received
- Published
- 2026-09-24
- Last modified
- 2026-10-03
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Description
In the Linux kernel, the following vulnerability has been resolved:
ipv6: addrconf: fix temp address generation after prefix deprecation
When a router temporarily deprecates an IPv6 prefix (either by sending a
Router Advertisement with Preferred Lifetime = 0 or by letting the
lifetime expire) and later restores it, the kernel permanently loses its
ability to generate temporary privacy addresses (RFC 8981) for that
prefix.
This happens because the address worker attempts to generate a
replacement temporary address when the current one nears expiration. As
the base prefix is deprecated already, the generation fails after
marking the temporary address as already having spawned a replacement
(ifp->regen_count++).
When the router eventually restores the prefix, the temporary address
becomes active again. However, once it naturally expires, the address
worker sees this temporary address already tried to generate one and
skips the regeneration.
Fix the issue by resetting the regen_count check of the latest temp
address generated for the prefix updated by the incoming RA.
References
- https://git.kernel.org/stable/c/4df5597c65446135362f72880995e8920f058fa0 git.kernel.org
- https://git.kernel.org/stable/c/4f7d2a8dc364c4e55d0a1533451339008512933f git.kernel.org
- https://git.kernel.org/stable/c/6da8ba900b85e6478e211427630c67595fb707a4 git.kernel.org
- https://git.kernel.org/stable/c/b00f7c1da82a809156f785ed37536c2d2584927d git.kernel.org
- https://git.kernel.org/stable/c/bff7b87dfa28a1502c18d0c6f1fadda5162fa854 git.kernel.org
- https://git.kernel.org/stable/c/e20d8922aa8fe441d291364c96c2179a005b79ea git.kernel.org
- https://git.kernel.org/stable/c/f601ec5c92b3260c742f27a5d2fd289e30ae798f git.kernel.org