From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Fri, 27 Mar 2020 17:43:05 +0100
Subject: netfilter: nft_dynset: validate set expression definition
Patch-mainline: v5.7-rc1
Git-commit: 8548bde9890fd0316f49d3c6937573c18261f68f
References: bsc#1176447

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

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 net/netfilter/nft_dynset.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

--- a/net/netfilter/nft_dynset.c
+++ b/net/netfilter/nft_dynset.c
@@ -187,6 +187,11 @@ static int nft_dynset_init(const struct
 						     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
 
 	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
 	priv->set = set;
 	return 0;
 
-err1:
+err_expr_free:
 	if (priv->expr != NULL)
 		nft_expr_destroy(ctx, priv->expr);
 	return err;