CVE-2026-64116 ipv6: ioam: add NULL check for idev in ipv6_hop_ioam()

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 in6devgetskb-dev-cnf.ioam6enabled without validating the returned idev pointer. Because addrconfifdown can concurrently cle...