CVE-2026-74581: Undefined Security Weakness

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

net: ipv6: clear suppressed fib6 rule result

fib6_rule_suppress() drops a suppressed route with ip6_rt_put_flags(), but leaves res->rt6 pointing at the released rt6_info.

If no later rule supplies a replacement, fib6_rule_lookup() still sees res.rt6 and returns that stale dst to its caller. A suppressing rule can therefore leak a released route back to rt6_lookup(), and the next put hits rcuref_put_slowpath() from dst_release().

Clear res->rt6 when suppressing the route so suppressed lookups fall through to the null dst instead of reusing the released one.