From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 52C24C4CEC4 for ; Thu, 19 Sep 2019 22:15:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2377221BE5 for ; Thu, 19 Sep 2019 22:15:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568931302; bh=9ZkUmIAtqapg5V4o9+m2L/LvSQjknh64QISz0pC6Op8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Uoz/CV2919w/nszUepk75OjD/YMn4x5giteBIu9p2DWBlr25mnUN3VP35QNY5wHtc aDcwf+95vBeYECqJfS8m5WENq9ST4LcpbPQmMu+yTQyWDc1I38sdBO1LiYKNK1+b32 XiSTw3PQz4MsDdJUOE4sweuoYqwmI+ox7XAASiN8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392116AbfISWPA (ORCPT ); Thu, 19 Sep 2019 18:15:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:54736 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2393839AbfISWO7 (ORCPT ); Thu, 19 Sep 2019 18:14:59 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 393CB218AF; Thu, 19 Sep 2019 22:14:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568931298; bh=9ZkUmIAtqapg5V4o9+m2L/LvSQjknh64QISz0pC6Op8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Nz3kV8nie4T7bPraOQXw3Ot1JT0MHXqZGQnBsLWUoqYOaiuecEYqwI1l5P9Y5mOaU 8+vZhDCf2gi3is5zxS/HbEqMYZl1CCaKV+7M/uzL+LYx9A3p4gY/+8zKvTSEK8Pk9z /Gtk3wo4byw6lQp8ArlayktwZdiHTOAzjB4BGyCo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sven Eckelmann , Simon Wunderlich , Sasha Levin Subject: [PATCH 4.19 43/79] batman-adv: Only read OGM2 tvlv_len after buffer len check Date: Fri, 20 Sep 2019 00:03:28 +0200 Message-Id: <20190919214811.470416788@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190919214807.612593061@linuxfoundation.org> References: <20190919214807.612593061@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Sven Eckelmann [ Upstream commit 0ff0f15a32c093381ad1abc06abe85afb561ab28 ] Multiple batadv_ogm2_packet can be stored in an skbuff. The functions batadv_v_ogm_send_to_if() uses batadv_v_ogm_aggr_packet() to check if there is another additional batadv_ogm2_packet in the skb or not before they continue processing the packet. The length for such an OGM2 is BATADV_OGM2_HLEN + batadv_ogm2_packet->tvlv_len. The check must first check that at least BATADV_OGM2_HLEN bytes are available before it accesses tvlv_len (which is part of the header. Otherwise it might try read outside of the currently available skbuff to get the content of tvlv_len. Fixes: 9323158ef9f4 ("batman-adv: OGMv2 - implement originators logic") Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich Signed-off-by: Sasha Levin --- net/batman-adv/bat_v_ogm.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c index 2948b41b06d47..d241ccc0ca027 100644 --- a/net/batman-adv/bat_v_ogm.c +++ b/net/batman-adv/bat_v_ogm.c @@ -643,17 +643,23 @@ batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv, * batadv_v_ogm_aggr_packet() - checks if there is another OGM aggregated * @buff_pos: current position in the skb * @packet_len: total length of the skb - * @tvlv_len: tvlv length of the previously considered OGM + * @ogm2_packet: potential OGM2 in buffer * * Return: true if there is enough space for another OGM, false otherwise. */ -static bool batadv_v_ogm_aggr_packet(int buff_pos, int packet_len, - __be16 tvlv_len) +static bool +batadv_v_ogm_aggr_packet(int buff_pos, int packet_len, + const struct batadv_ogm2_packet *ogm2_packet) { int next_buff_pos = 0; - next_buff_pos += buff_pos + BATADV_OGM2_HLEN; - next_buff_pos += ntohs(tvlv_len); + /* check if there is enough space for the header */ + next_buff_pos += buff_pos + sizeof(*ogm2_packet); + if (next_buff_pos > packet_len) + return false; + + /* check if there is enough space for the optional TVLV */ + next_buff_pos += ntohs(ogm2_packet->tvlv_len); return (next_buff_pos <= packet_len) && (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES); @@ -830,7 +836,7 @@ int batadv_v_ogm_packet_recv(struct sk_buff *skb, ogm_packet = (struct batadv_ogm2_packet *)skb->data; while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb), - ogm_packet->tvlv_len)) { + ogm_packet)) { batadv_v_ogm_process(skb, ogm_offset, if_incoming); ogm_offset += BATADV_OGM2_HLEN; -- 2.20.1