From 9d3f027327c2fa265f7f85ead41294792c3296ed Mon Sep 17 00:00:00 2001 From: Ren Wei Date: Wed, 25 Mar 2026 14:11:00 +0100 Subject: [PATCH] netfilter: ip6t_rt: reject oversized addrnr in rt_mt6_check() Reject rt match rules whose addrnr exceeds IP6T_RT_HOPS. rt_mt6() expects addrnr to stay within the bounds of rtinfo->addrs[]. Validate addrnr during rule installation so malformed rules are rejected before the match logic can use an out-of-range value. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Yifan Wu Reported-by: Juefei Pu Co-developed-by: Yuan Tan Signed-off-by: Yuan Tan Suggested-by: Xin Liu Tested-by: Yuhang Zheng Signed-off-by: Ren Wei Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/ipv6/netfilter/ip6t_rt.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/ipv6/netfilter/ip6t_rt.c b/net/ipv6/netfilter/ip6t_rt.c index 4ad8b2032f1f..5561bd9cea81 100644 --- a/net/ipv6/netfilter/ip6t_rt.c +++ b/net/ipv6/netfilter/ip6t_rt.c @@ -157,6 +157,10 @@ static int rt_mt6_check(const struct xt_mtchk_param *par) pr_debug("unknown flags %X\n", rtinfo->invflags); return -EINVAL; } + if (rtinfo->addrnr > IP6T_RT_HOPS) { + pr_debug("too many addresses specified\n"); + return -EINVAL; + } if ((rtinfo->flags & (IP6T_RT_RES | IP6T_RT_FST_MASK)) && (!(rtinfo->flags & IP6T_RT_TYP) || (rtinfo->rt_type != 0) ||