Subject: [PATCH 4/4] batman-adv: Fix invalid stack access in batadv_dat_select_candidates

From: Antonio Quartulli <[email-masked]>
Date: Mon, 7 Dec 2015 23:12:15 +0800

From: Sven Eckelmann <[email-masked]>

batadv_dat_select_candidates provides an u32 to batadv_hash_dat but it
needs a batadv_dat_entry with at least ip and vid filled in.

Fixes: 3e26722bc9f2 ("batman-adv: make the Distributed ARP Table vlan aware")
Signed-off-by: Sven Eckelmann <[email-masked]>
Acked-by: Antonio Quartulli <[email-masked]>
Signed-off-by: Marek Lindner <[email-masked]>
Signed-off-by: Antonio Quartulli <[email-masked]>
---
 net/batman-adv/distributed-arp-table.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c
index 83bc1aa..a49c705 100644
--- a/net/batman-adv/distributed-arp-table.c
+++ b/net/batman-adv/distributed-arp-table.c
@@ -566,6 +566,7 @@ batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst)
 	int select;
 	batadv_dat_addr_t last_max = BATADV_DAT_ADDR_MAX, ip_key;
 	struct batadv_dat_candidate *res;
+	struct batadv_dat_entry dat;
 
 	if (!bat_priv->orig_hash)
 		return NULL;
@@ -575,7 +576,9 @@ batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst)
 	if (!res)
 		return NULL;
 
-	ip_key = (batadv_dat_addr_t)batadv_hash_dat(&ip_dst,
+	dat.ip = ip_dst;
+	dat.vid = 0;
+	ip_key = (batadv_dat_addr_t)batadv_hash_dat(&dat,
 						    BATADV_DAT_ADDR_MAX);
 
 	batadv_dbg(BATADV_DBG_DAT, bat_priv,
-- 
2.6.3