src: fix missing error checking in parser functions

Bail out on errors in several nftnl_*_nlmsg_parse() functions. We can
overwrite the previous error value, and may execute code which should
not.

Bad way:
	int f() {
		int ret;

		ret = g();
		ret = h();

		return ret;
	}

Good way:
	int f() {
		int ret;

		ret = g();
		if (ret < 0)
			return ret;

		ret = h();
		if (ret < 0)
			return ret;

		return 0;
	}

Signed-off-by: Carlos Falgueras García <carlosfg@riseup.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 6 insertions, 3 deletions

diff --git a/src/set.c b/src/set.c
index 08d5797..47e0c45 100644
--- a/src/set.c
+++ b/src/set.c
@@ -433,7 +433,7 @@ int nftnl_set_nlmsg_parse(const struct nlmsghdr *nlh, struct nftnl_set *s)
 {
 	struct nlattr *tb[NFTA_SET_MAX+1] = {};
 	struct nfgenmsg *nfg = mnl_nlmsg_get_payload(nlh);
-	int ret = 0;
+	int ret;
 
 	if (mnl_attr_parse(nlh, sizeof(*nfg), nftnl_set_parse_attr_cb, tb) < 0)
 		return -1;
@@ -490,13 +490,16 @@ int nftnl_set_nlmsg_parse(const struct nlmsghdr *nlh, struct nftnl_set *s)
 		s->gc_interval = ntohl(mnl_attr_get_u32(tb[NFTA_SET_GC_INTERVAL]));
 		s->flags |= (1 << NFTNL_SET_GC_INTERVAL);
 	}
-	if (tb[NFTA_SET_DESC])
+	if (tb[NFTA_SET_DESC]) {
 		ret = nftnl_set_desc_parse(s, tb[NFTA_SET_DESC]);
+		if (ret < 0)
+			return ret;
+	}
 
 	s->family = nfg->nfgen_family;
 	s->flags |= (1 << NFTNL_SET_FAMILY);
 
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL_ALIAS(nftnl_set_nlmsg_parse, nft_set_nlmsg_parse);