diff --git a/net/netfilter/xt_tcpmss.c b/net/netfilter/xt_tcpmss.c index b9da8269161d..b08b077d7f0a 100644 --- a/net/netfilter/xt_tcpmss.c +++ b/net/netfilter/xt_tcpmss.c @@ -78,10 +78,23 @@ tcpmss_mt(const struct sk_buff *skb, struct xt_action_param *par) return false; } +static int tcpmss_mt_check(const struct xt_mtchk_param *par) +{ + const struct xt_tcpmss_match_info *info = par->matchinfo; + + if (info->mss_min > info->mss_max) + return -EINVAL; + if (info->invert > 1) + return -EINVAL; + + return 0; +} + static struct xt_match tcpmss_mt_reg[] __read_mostly = { { .name = "tcpmss", .family = NFPROTO_IPV4, + .checkentry = tcpmss_mt_check, .match = tcpmss_mt, .matchsize = sizeof(struct xt_tcpmss_match_info), .proto = IPPROTO_TCP,