Staging: batman-adv: protect against ogm packet overflow by checking table length

Reported-by: Sam Yeung <sam.cwyeung@gmail.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 7 insertions, 2 deletions

diff --git a/drivers/staging/batman-adv/translation-table.c b/drivers/staging/batman-adv/translation-table.c
index 12b23259c385..681ccbda3eac 100644
--- a/drivers/staging/batman-adv/translation-table.c
+++ b/drivers/staging/batman-adv/translation-table.c
@@ -59,6 +59,7 @@ void hna_local_add(struct net_device *soft_iface, uint8_t *addr)
         struct hna_global_entry *hna_global_entry;
         struct hashtable_t *swaphash;
         unsigned long flags;
+        int required_bytes;
 
         spin_lock_irqsave(&bat_priv->hna_lhash_lock, flags);
         hna_local_entry =
@@ -74,8 +75,12 @@ void hna_local_add(struct net_device *soft_iface, uint8_t *addr)
         /* only announce as many hosts as possible in the batman-packet and
            space in batman_packet->num_hna That also should give a limit to
            MAC-flooding. */
-        if ((bat_priv->num_local_hna + 1 > (ETH_DATA_LEN - BAT_PACKET_LEN)
-                                                                / ETH_ALEN) ||
+        required_bytes = (bat_priv->num_local_hna + 1) * ETH_ALEN;
+        required_bytes += BAT_PACKET_LEN;
+
+        if ((required_bytes > ETH_DATA_LEN) ||
+            (atomic_read(&bat_priv->aggregation_enabled) &&
+             required_bytes > MAX_AGGREGATION_BYTES) ||
             (bat_priv->num_local_hna + 1 > 255)) {
                 bat_dbg(DBG_ROUTES, bat_priv,
                         "Can't add new local hna entry (%pM): "