struct nft_expr_info allows to store up to NFT_EXPR_MAXATTR (16)
attributes when parsing netlink attributes.
Rise a warning in case there is ever a nft expression whose .maxattr
goes beyond this number of expressions, in such case, struct nft_expr_info
needs to be updated.
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
net/netfilter/nf_tables_api.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index a926f10db125..95eefb6d7827 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2968,6 +2968,9 @@ static int nf_tables_delchain(struct sk_buff *skb, const struct nfnl_info *info,
*/
int nft_register_expr(struct nft_expr_type *type)
{
+ if (WARN_ON_ONCE(type->maxattr > NFT_EXPR_MAXATTR))
+ return -ENOMEM;
+
nfnl_lock(NFNL_SUBSYS_NFTABLES);
if (type->family == NFPROTO_UNSPEC)
list_add_tail_rcu(&type->list, &nf_tables_expressions);
--
2.30.2
