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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 60B8CC41514 for ; Wed, 4 Sep 2019 16:18:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3A8BA22CED for ; Wed, 4 Sep 2019 16:18:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567613912; bh=GKqQqdOW1fttTEPCtnHImZlE451qBP1GL+jPuoydfcU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=s39TTnZrvo1fYGDdPDuQwU1AiGVZaQ25L1yVO8PwmaUfU9yU+C7GXjhEBkgYMRQ9i zhXegv3NkpG4/C3W/H82EOw4Gl09q4e2KkqZtnMDTjBVJ+r5baDKrTIxBz5qrAXpVm C3fVN0I0t+243fwYIeagqoX2339plo+Xh684OBIY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732091AbfIDP6m (ORCPT ); Wed, 4 Sep 2019 11:58:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:60976 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732047AbfIDP6i (ORCPT ); Wed, 4 Sep 2019 11:58:38 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 08AC42070C; Wed, 4 Sep 2019 15:58:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567612716; bh=GKqQqdOW1fttTEPCtnHImZlE451qBP1GL+jPuoydfcU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oZY0+fD0NVIgd9uotyr1rqdAL9MFyfo2nhczVVXaMQnZQVTMwWZugzJEMe67uPE6K SIgcOg3/pBuMGCFha8RS7/DBRip312o28HPKSPXvEqptX9bCDEUu41UsZpGZRp1UQx iVaS7NseOUpP65VmU54gGmoSu6k4Q0SwhjevTEqU= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Sven Eckelmann , Simon Wunderlich , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.2 39/94] batman-adv: Only read OGM2 tvlv_len after buffer len check Date: Wed, 4 Sep 2019 11:56:44 -0400 Message-Id: <20190904155739.2816-39-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190904155739.2816-1-sashal@kernel.org> References: <20190904155739.2816-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@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 fad95ef64e01a..bc06e3cdfa84f 100644 --- a/net/batman-adv/bat_v_ogm.c +++ b/net/batman-adv/bat_v_ogm.c @@ -631,17 +631,23 @@ 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); @@ -818,7 +824,7 @@ 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