From c918687f5e3962375a19de6ded3c1be85ebdbcd6 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Mon, 10 Nov 2014 20:53:55 +0100 Subject: [PATCH] netfilter: nft_compat: relax chain type validation Check for nat chain dependency only, which is the one that can actually crash the kernel. Don't care if mangle, filter and security specific match and targets are used out of their scope, they are harmless. This restores iptables-compat with mangle specific match/target when used out of the OUTPUT chain, that are actually emulated through filter chains, which broke when performing strict validation. Fixes: f3f5dde ("netfilter: nft_compat: validate chain type in match/target") Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_compat.c | 32 ++------------------------------ 1 file changed, 2 insertions(+), 30 deletions(-) diff --git a/net/netfilter/nft_compat.c b/net/netfilter/nft_compat.c index b92f129beade..70dc96516305 100644 --- a/net/netfilter/nft_compat.c +++ b/net/netfilter/nft_compat.c @@ -21,45 +21,17 @@ #include #include -static const struct { - const char *name; - u8 type; -} table_to_chaintype[] = { - { "filter", NFT_CHAIN_T_DEFAULT }, - { "raw", NFT_CHAIN_T_DEFAULT }, - { "security", NFT_CHAIN_T_DEFAULT }, - { "mangle", NFT_CHAIN_T_ROUTE }, - { "nat", NFT_CHAIN_T_NAT }, - { }, -}; - -static int nft_compat_table_to_chaintype(const char *table) -{ - int i; - - for (i = 0; table_to_chaintype[i].name != NULL; i++) { - if (strcmp(table_to_chaintype[i].name, table) == 0) - return table_to_chaintype[i].type; - } - - return -1; -} - static int nft_compat_chain_validate_dependency(const char *tablename, const struct nft_chain *chain) { - enum nft_chain_type type; const struct nft_base_chain *basechain; if (!tablename || !(chain->flags & NFT_BASE_CHAIN)) return 0; - type = nft_compat_table_to_chaintype(tablename); - if (type < 0) - return -EINVAL; - basechain = nft_base_chain(chain); - if (basechain->type->type != type) + if (strcmp(tablename, "nat") == 0 && + basechain->type->type != NFT_CHAIN_T_NAT) return -EINVAL; return 0; -- 2.20.1