nlmsg: fix valgrind warnings about padding

When using mnl_nlmsg_put_extra_header() it pads out the addtional
header but only zeros the original size not the padded value. Which
cause valgrind to complain about sendto() with uninitialized byte.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/src/nlmsg.c b/src/nlmsg.c
index cb2cbb8..000829e 100644
--- a/src/nlmsg.c
+++ b/src/nlmsg.c
@@ -105,8 +105,9 @@ void *
 mnl_nlmsg_put_extra_header(struct nlmsghdr *nlh, size_t size)
 {
 	char *ptr = (char *)nlh + nlh->nlmsg_len;
-	nlh->nlmsg_len += MNL_ALIGN(size);
-	memset(ptr, 0, size);
+	size_t len = MNL_ALIGN(size);
+	nlh->nlmsg_len += len;
+	memset(ptr, 0, len);
 	return ptr;
 }
 EXPORT_SYMBOL(mnl_nlmsg_put_extra_header);