No problem for iptables as priorities are fixed values defined in the
nat modules, but in nftables the priority its coming from userspace.

Reject in case we see that such a hook would not work.

Signed-off-by: Florian Westphal <[email protected]>
---
 net/netfilter/nf_tables_api.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index f000d4399c7a..4ed66f1b40b5 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -1303,6 +1303,11 @@ static int nft_chain_parse_hook(struct net *net,
        }
        if (!(type->hook_mask & (1 << hook->num)))
                return -EOPNOTSUPP;
+
+       if (type->type == NFT_CHAIN_T_NAT &&
+           hook->priority <= NF_IP_PRI_CONNTRACK)
+               return -EINVAL;
+
        if (!try_module_get(type->owner))
                return -ENOENT;
 
-- 
2.13.6

--
To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to