From f1ee0ffbc0243f0a9dc4a9348fffed710d9ea419 Mon Sep 17 00:00:00 2001
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Thu, 14 Dec 2023 22:43:22 +0100
Subject: [PATCH] netfilter: nf_tables: validate chain type update if available
[ Upstream commit aaba7ddc8507f4ad5bbd07988573967632bc2385 ]
Parse netlink attribute containing the chain type in this update, to
bail out if this is different from the existing type.
Otherwise, it is possible to define a chain with the same name, hook and
priority but different type, which is silently ignored.
Fixes: 96518518cc41 ("netfilter: add nftables")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/netfilter/nf_tables_api.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 24cad36565d7..5822912045ef 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2263,7 +2263,16 @@ static int nft_chain_parse_hook(struct net *net,
return -EOPNOTSUPP;
}
- type = basechain->type;
+ if (nla[NFTA_CHAIN_TYPE]) {
+ type = __nf_tables_chain_type_lookup(nla[NFTA_CHAIN_TYPE],
+ family);
+ if (!type) {
+ NL_SET_BAD_ATTR(extack, nla[NFTA_CHAIN_TYPE]);
+ return -ENOENT;
+ }
+ } else {
+ type = basechain->type;
+ }
}
if (!try_module_get(type->owner)) {