diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index 6c8604390266..cd663310b227 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -658,6 +658,8 @@ static void igmp6_group_added(struct ifmcaddr6 *mc)
 	struct net_device *dev = mc->idev->dev;
 	char buf[MAX_ADDR_LEN];
 
+	memset(buf, 0, sizeof(buf));
+
 	if (IPV6_ADDR_MC_SCOPE(&mc->mca_addr) <
 	    IPV6_ADDR_SCOPE_LINKLOCAL)
 		return;