[v2,2/2] batman-adv: check for tt_reponse real length
Commit Message
Before accessing the TT_RESPONSE message payload, we have to ensure that the
real length of the packet reflect the claimed one (contained in
tt_response->tt_data field)
Reported-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
---
corrected skb length check
routing.c | 13 +++++++++++++
1 files changed, 13 insertions(+), 0 deletions(-)
Comments
On Wednesday, October 12, 2011 15:10:58 Antonio Quartulli wrote:
> if (tt_query->flags & TT_FULL_TABLE)
> + tt_len = tt_query->tt_data * ETH_ALEN;
Odd, I had the feeling the full table also uses 'struct tt_change' and not
plain ethernet addresses anymore.
From translation-table.c (send_my_tt_response):
tt_len = (uint16_t)atomic_read(&bat_priv->num_local_tt) *
sizeof(struct tt_change);
Regards,
Marek
@@ -578,6 +578,7 @@ int recv_tt_query(struct sk_buff *skb, struct hard_iface *recv_if)
{
struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
struct tt_query_packet *tt_query;
+ uint16_t tt_len;
struct ethhdr *ethhdr;
/* drop packet if it has not necessary minimum size */
@@ -622,6 +623,18 @@ int recv_tt_query(struct sk_buff *skb, struct hard_iface *recv_if)
if (skb_linearize(skb) < 0)
goto out;
+ if (tt_query->flags & TT_FULL_TABLE)
+ tt_len = tt_query->tt_data * ETH_ALEN;
+ else
+ tt_len = tt_query->tt_data *
+ sizeof(struct tt_change);
+
+ /* Ensure we have all the claimed data */
+ if (unlikely(skb_headlen(skb) <
+ sizeof(struct tt_query_packet) +
+ tt_len))
+ goto out;
+
handle_tt_response(bat_priv, tt_query);
} else {
bat_dbg(DBG_TT, bat_priv,