From mboxrd@z Thu Jan 1 00:00:00 1970 From: Antonio Quartulli Subject: [PATCH 02/19] batman-adv: fix skb->data assignment Date: Mon, 18 Jun 2012 22:39:06 +0200 Message-ID: <1340051963-14836-3-git-send-email-ordex@autistici.org> References: <1340051963-14836-1-git-send-email-ordex@autistici.org> Reply-To: The list for a Better Approach To Mobile Ad-hoc Networking Cc: netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, b.a.t.m.a.n-ZwoEplunGu2X36UT3dwllkB+6BGkLq7r@public.gmane.org, stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org Return-path: In-Reply-To: <1340051963-14836-1-git-send-email-ordex-GaUfNO9RBHfsrOwW+9ziJQ@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: b.a.t.m.a.n-bounces-ZwoEplunGu2X36UT3dwllkB+6BGkLq7r@public.gmane.org Errors-To: b.a.t.m.a.n-bounces-ZwoEplunGu2X36UT3dwllkB+6BGkLq7r@public.gmane.org List-Id: netdev.vger.kernel.org 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 Cc: Signed-off-by: Sven Eckelmann --- 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 840e2c6..015471d 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); -- 1.7.9.4