From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Wed, 16 Oct 2019 14:25:05 +0200
Subject: netfilter: nf_tables: allow netdevice to be used only once per
flowtable
Patch-mainline: v5.5-rc1
Git-commit: b75a3e8371bce7985d3d149ad3442bf2a036065c
References: bsc#1176447
Allow netdevice only once per flowtable, otherwise hit EEXIST.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
net/netfilter/nf_tables_api.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -1538,6 +1538,19 @@ err_hook_alloc:
return ERR_PTR(err);
}
+static bool nft_hook_list_find(struct list_head *hook_list,
+ const struct nft_hook *this)
+{
+ struct nft_hook *hook;
+
+ list_for_each_entry(hook, hook_list, list) {
+ if (this->ops.dev == hook->ops.dev)
+ return true;
+ }
+
+ return false;
+}
+
static int nf_tables_parse_netdev_hooks(struct net *net,
const struct nlattr *attr,
struct list_head *hook_list)
@@ -1557,6 +1570,10 @@ static int nf_tables_parse_netdev_hooks(
err = PTR_ERR(hook);
goto err_hook;
}
+ if (nft_hook_list_find(hook_list, hook)) {
+ err = -EEXIST;
+ goto err_hook;
+ }
list_add_tail(&hook->list, hook_list);
n++;