[PATCH nft 2/2] netlink_delinearize: release expression before calling netlink_parse_concat_expr()

[Pablo Neira Ayuso <pablo@netfilter.org>]

netlink_get_register() clones the expression in the register. Release
this expression before calling netlink_parse_concat_expr() to
deconstruct the concatenation.

==15069==    at 0x4C2BBAF: malloc (vg_replace_malloc.c:299)
==15069==    by 0x4E79508: xmalloc (utils.c:36)
==15069==    by 0x4E795ED: xzalloc (utils.c:65)
==15069==    by 0x4E6029B: dtype_alloc (datatype.c:1073)
==15069==    by 0x4E6029B: concat_type_alloc (datatype.c:1127)
==15069==    by 0x4E6D3B3: netlink_delinearize_set (netlink.c:578)
==15069==    by 0x4E6D68E: list_set_cb (netlink.c:648)
==15069==    by 0x5F34023: nftnl_set_list_foreach (set.c:780)
==15069==    by 0x4E6D6F3: netlink_list_sets (netlink.c:669)
==15069==    by 0x4E5A7A3: cache_init_objects (rule.c:159)
==15069==    by 0x4E5A7A3: cache_init (rule.c:216)
==15069==    by 0x4E5A7A3: cache_update (rule.c:266)
==15069==    by 0x4E7E09E: nft_evaluate (libnftables.c:388)
==15069==    by 0x4E7E85B: nft_run_cmd_from_buffer (libnftables.c:428)

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 src/netlink_delinearize.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/netlink_delinearize.c b/src/netlink_delinearize.c
index a1c775e679e4..0270e1fd7067 100644
--- a/src/netlink_delinearize.c
+++ b/src/netlink_delinearize.c
@@ -293,6 +293,7 @@ static void netlink_parse_cmp(struct netlink_parse_ctx *ctx,
 	    expr_basetype(left) != &string_type) {
 		return netlink_error(ctx, loc, "Relational expression size mismatch");
 	} else if (left->len > 0 && left->len < right->len) {
+		expr_free(left);
 		left = netlink_parse_concat_expr(ctx, loc, sreg, right->len);
 		if (left == NULL)
 			return;
@@ -329,6 +330,7 @@ static void netlink_parse_lookup(struct netlink_parse_ctx *ctx,
 				     "Lookup expression has no left hand side");
 
 	if (left->len < set->key->len) {
+		expr_free(left);
 		left = netlink_parse_concat_expr(ctx, loc, sreg, set->key->len);
 		if (left == NULL)
 			return;
@@ -1317,6 +1319,7 @@ static void netlink_parse_dynset(struct netlink_parse_ctx *ctx,
 				     "Dynset statement has no key expression");
 
 	if (expr->len < set->key->len) {
+		expr_free(expr);
 		expr = netlink_parse_concat_expr(ctx, loc, sreg, set->key->len);
 		if (expr == NULL)
 			return;
@@ -1408,6 +1411,7 @@ static void netlink_parse_objref(struct netlink_parse_ctx *ctx,
 					     "objref expression has no left hand side");
 
 		if (left->len < set->key->len) {
+			expr_free(left);
 			left = netlink_parse_concat_expr(ctx, loc, sreg, set->key->len);
 			if (left == NULL)
 				return;
-- 
2.11.0