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From:   Colin King <colin.king@canonical.com>
To:     Marek Lindner <mareklindner@neomailbox.ch>,
        Simon Wunderlich <sw@simonwunderlich.de>,
        Antonio Quartulli <a@unstable.cc>,
        "David S . Miller" <davem@davemloft.net>,
        b.a.t.m.a.n@lists.open-mesh.org, netdev@vger.kernel.org
Cc:     kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH][next] batman-adv: don't pass a NULL hard_iface to batadv_hardif_put
Date:   Fri, 23 Mar 2018 22:53:50 +0000
Message-Id: <20180323225350.7350-1-colin.king@canonical.com>
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From: Colin Ian King <colin.king@canonical.com>

In the case where hard_iface is NULL, the error path may pass a null
pointer to batadv_hardif_put causing a null pointer dereference error.
Avoid this by only calling the function if  hard_iface not null.

Detected by CoverityScan, CID#1466456 ("Explicit null dereferenced")

Fixes: 53dd9a68ba68 ("batman-adv: add multicast flags netlink support")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 net/batman-adv/multicast.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c
index de3a055f7dd8..bd0ea374d043 100644
--- a/net/batman-adv/multicast.c
+++ b/net/batman-adv/multicast.c
@@ -1536,7 +1536,7 @@ batadv_mcast_netlink_get_primary(struct netlink_callback *cb,
 
 	if (!ret && primary_if)
 		*primary_if = hard_iface;
-	else
+	else if (hard_iface)
 		batadv_hardif_put(hard_iface);
 
 	return ret;
-- 
2.15.1