CVE-2026-64116

In the Linux kernel, the following vulnerability has been resolved:

ipv6: ioam: add NULL check for idev in ipv6hopioam()

Reported by Sashiko:

The function ipv6hopioam() accesses __in6devget(skb->dev)->cnf.ioam6_enabled without validating the returned idev pointer. Because addrconfifdown() can concurrently clear dev->ip6ptr via RCU, __in6devget() can return NULL during interface teardown, which could cause a NULL pointer dereference when processing an IOAM Hop-by-Hop option.

Let's add a check and use SKBDROPREASON_IPV6DISABLED accordingly.