batman-adv: Fix invalid stack access in batadv_dat_select_candidates

commit b7fe3d4f4a65bc675e737d88071300ea9c4bcddd upstream.

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 <sven@open-mesh.com>
Acked-by: Antonio Quartulli <antonio@meshcoding.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c
index 28d70b941bb59f1029b8018c2a8ef1c1664c7cdc..8162e3fa76db8464290b3a764421c6c04a7852ac 100644 (file)
--- a/net/batman-adv/distributed-arp-table.c
+++ b/net/batman-adv/distributed-arp-table.c
@@ -534,6 +534,7 @@ 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;
@@ -542,7 +543,9 @@ 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,