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authorAntonio Quartulli <ordex@autistici.org>2012-06-29 22:58:03 +0200
committerBen Hutchings <ben@decadent.org.uk>2012-07-04 05:44:21 +0100
commit6f4d747dfba5228b6041a9637fa0d944922ce72c (patch)
treeab3b6bfc24e371940d9ebf148b81daae7d736d3a
parent4c42ad8fcf33fee7b949a6355b71a773843131b9 (diff)
downloadlwn-6f4d747dfba5228b6041a9637fa0d944922ce72c.tar.gz
lwn-6f4d747dfba5228b6041a9637fa0d944922ce72c.zip
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 <ordex@autistici.org> Signed-off-by: David S. Miller <davem@davemloft.net> [This patch is a backport for kernel versions 3.1 and 3.2 - Antonio] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r--net/batman-adv/routing.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index f961cc5eade5..da587ad189f8 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -619,6 +619,8 @@ int recv_tt_query(struct sk_buff *skb, struct hard_iface *recv_if)
/* packet needs to be linearized 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);