[ 06/98] batman-adv: verify tt len does not exceed packet len

Greg Kroah-Hartman
2013-03-26T23:49:48Z

From: Marek Lindner <lindner_marek@yahoo.de>

[ Upstream commit b47506d91259c29b9c75c404737eb6525556f9b4 ]

batadv_iv_ogm_process() accesses the packet using the tt_num_changes
attribute regardless of the real packet len (assuming the length check
was done before). Therefore a length check is needed to avoid reading
random memory.

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/batman-adv/bat_iv_ogm.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -1298,7 +1298,8 @@ static int batadv_iv_ogm_receive(struct
batadv_ogm_packet = (struct batadv_ogm_packet *)packet_buff;

/* unpack the aggregated packets and process them one by one */
- do {
+ while (batadv_iv_ogm_aggr_packet(buff_pos, packet_len,
+ batadv_ogm_packet->tt_num_changes)) {
tt_buff = packet_buff + buff_pos + BATADV_OGM_HLEN;

batadv_iv_ogm_process(ethhdr, batadv_ogm_packet, tt_buff,
@@ -1309,8 +1310,7 @@ static int batadv_iv_ogm_receive(struct

packet_pos = packet_buff + buff_pos;
batadv_ogm_packet = (struct batadv_ogm_packet *)packet_pos;
- } while (batadv_iv_ogm_aggr_packet(buff_pos, packet_len,
- batadv_ogm_packet->tt_num_changes));
+ }

kfree_skb(skb);
return NET_RX_SUCCESS;