commit 2c995ff892313009e336ecc8ec3411022f5b1c39 upstream.
skb_linearize(skb) possibly rearranges the skb internal data and then changes the skb->data pointer value. For this reason any other pointer in the code that was assigned skb->data before invoking skb_linearise(skb) must be re-assigned.
In the current tt_query message handling code this is not done and therefore, in case of skb linearization, the pointer used to handle the packet header ends up in pointing to poisoned memory. The packet is then dropped but the translation-table mechanism is corrupted.
Signed-off-by: Antonio Quartulli ordex@autistici.org Signed-off-by: Sven Eckelmann sven@narfation.org --- Hello,
the patch committed upstream already contains Cc: stable@vger.kernel.org but that patch does apply only on 3.5, 3.4 and 3.3.
This patch is a backport for kernel versions 3.1 and 3.2
Thank you, Antonio
net/batman-adv/routing.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c index 0f32c81..55136e5 100644 --- a/net/batman-adv/routing.c +++ b/net/batman-adv/routing.c @@ -1246,6 +1246,8 @@ int recv_tt_query(struct sk_buff *skb, struct hard_iface *recv_if) /* packet needs to be linearised to access the TT changes */ if (skb_linearize(skb) < 0) goto out; + /* skb_linearize() possibly changed skb->data */ + tt_query = (struct tt_query_packet *)skb->data;
if (is_my_mac(tt_query->dst)) handle_tt_response(bat_priv, tt_query);