CVE-2026-72421 ipv4: fib: Don't ignore error route in local/main tables.

In the Linux kernel, the following vulnerability has been resolved: ipv4: fib: Don't ignore error route in local/main tables. When CONFIGIPMULTIPLETABLES is enabled but no rule is added, fiblookup performs route lookup directly on two tables. Since the first lookup does not properly bail out, the...