expr: immediate: fix leak in expression destroy path

The verdict can be a chain string, make sure we release it when the expression
is destroyed. This patch adds a new nft_free_data() for this purpose and use it
from the immediate expression.

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

1 files changed, 11 insertions, 0 deletions

diff --git a/src/expr/data_reg.c b/src/expr/data_reg.c
index b5fbdf2..b375db4 100644
--- a/src/expr/data_reg.c
+++ b/src/expr/data_reg.c
@@ -499,3 +499,14 @@ int nft_parse_data(union nft_data_reg *data, struct nlattr *attr, int *type)
 	return ret;
 }
 
+void nft_free_verdict(union nft_data_reg *data)
+{
+	switch(data->verdict) {
+	case NFT_JUMP:
+	case NFT_GOTO:
+		xfree(data->chain);
+		break;
+	default:
+		break;
+	}
+}