CVE-2026-74656: Undefined Security Weakness

In the Linux kernel, the following vulnerability has been resolved: ipv4: fix use-after-free in fibnhcupdatemtu fibnhcupdatemtu walks the nexthop exception table under RTNL, but RTNL does not serialize this walk with PMTU exception updates. The walk uses rcudereferenceprotected with a constant tr...