CVE-2026-68127

Description

In the Linux kernel, the following vulnerability has been resolved: ila: reload IPv6 header after pskb_may_pull in checksum adjust ila_csum_adjust_transport() caches ip6h = ipv6_hdr(skb) before calling pskb_may_pull(). On a non-linear skb whose transport header sits in a page fragment, pskb_may_pull() can call __pskb_pull_tail() / pskb_expand_head() and free the old skb head, leaving ip6h dangling; the following get_csum_diff(ip6h, p) then reads freed memory. ila_update_ipv6_locator() uses ip6h (and the iaddr derived from it) again after the csum-adjust call and additionally writes the new locator through that pointer. Impact: a remote IPv6 packet routed through a configured ILA csum-adjust-transport route or receive-side mapping triggers a slab-use-after-free in ila_update_ipv6_locator() (KASAN). The route or mapping requires CAP_NET_ADMIN to configure, but trigger packets are unauthenticated once it exists. Reload ip6h after each pskb_may_pull() in ila_csum_adjust_transport() before the csum-diff read. In ila_update_ipv6_locator() only the ILA_CSUM_ADJUST_TRANSPORT case pulls the skb, so reload ip6h and iaddr in that case alone before the destination-address write; the neutral-map modes never pull and keep their cached pointers.

CVSS 3.1 breakdown

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

References

• https://git.kernel.org/stable/c/1eadcb43893b897ade85ac5bf5c618054bc3c655
• https://git.kernel.org/stable/c/472aba2603ca74c4f7722cb0c0296942b0776b8d
• https://git.kernel.org/stable/c/7097a0280b178237265681be66d1bef11d15894b
• https://git.kernel.org/stable/c/896a9512d0d83c2a4b357e5585b7b62a8e3f95c1
• https://git.kernel.org/stable/c/92d3817649df2b0b6a008a686c8275c88d7ef594
• https://git.kernel.org/stable/c/ba353caafb06ccee57b78d3254e3cebf1dea4a93
• https://git.kernel.org/stable/c/c6a13ae00dab3a1a8c7cf2f843f0fc9e8d4b0ccc
• https://git.kernel.org/stable/c/e451a904606c571f731ef7a06b3398619dce5300

Frequently asked