From: Antonio Quartulli Date: Tue, 19 Jun 2012 09:26:39 +0000 (+0000) Subject: batman-adv: fix skb->data assignment X-Git-Tag: v3.4.5~87 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=a7faba5c5263f9d8a31b3f542a0504552fa80932;p=karo-tx-linux.git batman-adv: fix skb->data assignment 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 free'd memory. This bug was introduced by a73105b8d4c765d9ebfb664d0a66802127d8e4c7 (batman-adv: improved client announcement mechanism) Signed-off-by: Antonio Quartulli Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c index 7f8e15899417..8df3a1ff516b 100644 --- a/net/batman-adv/routing.c +++ b/net/batman-adv/routing.c @@ -618,6 +618,8 @@ int recv_tt_query(struct sk_buff *skb, struct hard_iface *recv_if) * changes */ if (skb_linearize(skb) < 0) goto out; + /* skb_linearize() possibly changed skb->data */ + tt_query = (struct tt_query_packet *)skb->data; tt_len = tt_query->tt_data * sizeof(struct tt_change);