From 20a58ff0980d07ca9dc215e7ad8d3249a69c963c Mon Sep 17 00:00:00 2001 From: Antonio Quartulli Date: Tue, 19 Jun 2012 09:26:39 +0000 Subject: [PATCH] batman-adv: fix skb->data assignment 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 81eee4f2876f6376baceb7f1336e42d2669c608e (batman-adv: improved client announcement mechanism) Signed-off-by: Antonio Quartulli Cc: Signed-off-by: David S. Miller --- 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 840e2c64a3011..015471d801b42 100644 --- a/net/batman-adv/routing.c +++ b/net/batman-adv/routing.c @@ -617,6 +617,8 @@ 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); -- 2.39.5