From d694b754894c93fb4d71a7f3699439dec111decc Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Fri, 2 Feb 2024 00:05:23 +0100 Subject: [PATCH] netfilter: nft_compat: restrict match/target protocol to u16 xt_check_{match,target} expects u16, but NFTA_RULE_COMPAT_PROTO is u32. NLA_POLICY_MAX(NLA_BE32, 65535) cannot be used because .max in nla_policy is s16, see 3e48be05f3c7 ("netlink: add attribute range validation to policy"). Fixes: 0ca743a55991 ("netfilter: nf_tables: add compatibility layer for x_tables") Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_compat.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nft_compat.c b/net/netfilter/nft_compat.c index ed71d5ecbe0a..1f9474fefe84 100644 --- a/net/netfilter/nft_compat.c +++ b/net/netfilter/nft_compat.c @@ -200,6 +200,7 @@ static const struct nla_policy nft_rule_compat_policy[NFTA_RULE_COMPAT_MAX + 1] static int nft_parse_compat(const struct nlattr *attr, u16 *proto, bool *inv) { struct nlattr *tb[NFTA_RULE_COMPAT_MAX+1]; + u32 l4proto; u32 flags; int err; @@ -218,7 +219,12 @@ static int nft_parse_compat(const struct nlattr *attr, u16 *proto, bool *inv) if (flags & NFT_RULE_COMPAT_F_INV) *inv = true; - *proto = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_PROTO])); + l4proto = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_PROTO])); + if (l4proto > U16_MAX) + return -EINVAL; + + *proto = l4proto; + return 0; } -- 2.39.5