[PATCH net-next 06/12] netfilter: xt_tcpmss: add checkentry for parameter validation
From: Florian Westphal <fw@strlen.de>
Date: 2026-07-02 10:50:39
Also in:
netfilter-devel
Subsystem:
netfilter, networking [general], the rest · Maintainers:
Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Feng Wu <redacted> Add tcpmss_mt_check() that validates mss_min <= mss_max and invert <= 1. Signed-off-by: Feng Wu <redacted> Signed-off-by: Florian Westphal <fw@strlen.de> --- net/netfilter/xt_tcpmss.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
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,
--
2.54.0