netfilter: nft_dynset: validate set expression definition

If the global set expression definition mismatches the dynset
expression, then bail out.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nft_dynset.c b/net/netfilter/nft_dynset.c
index d1b64c8de5853a40c3ffa427f4d19daf841d922a..64ca13a1885bc94622b340f2f58ebccd48307f5e 100644 (file)
--- a/net/netfilter/nft_dynset.c
+++ b/net/netfilter/nft_dynset.c
@@ -187,6 +187,11 @@ static int nft_dynset_init(const struct nft_ctx *ctx,
                                                     tb[NFTA_DYNSET_EXPR]);
                if (IS_ERR(priv->expr))
                        return PTR_ERR(priv->expr);
+
+               if (set->expr && set->expr->ops != priv->expr->ops) {
+                       err = -EOPNOTSUPP;
+                       goto err_expr_free;
+               }
        }
 
        nft_set_ext_prepare(&priv->tmpl);
@@ -205,7 +210,7 @@ static int nft_dynset_init(const struct nft_ctx *ctx,
 
        err = nf_tables_bind_set(ctx, set, &priv->binding);
        if (err < 0)
-               goto err1;
+               goto err_expr_free;
 
        if (set->size == 0)
                set->size = 0xffff;
@@ -213,7 +218,7 @@ static int nft_dynset_init(const struct nft_ctx *ctx,
        priv->set = set;
        return 0;
 
-err1:
+err_expr_free:
        if (priv->expr != NULL)
                nft_expr_destroy(ctx, priv->expr);
        return err;