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@xxxxxxxxxxxxx>
---
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 4c3de1a2c52b..5531b13d92b6 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2261,7 +2261,16 @@ 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)) {
--
2.30.2
