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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,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 106E0C282CE for ; Wed, 24 Apr 2019 18:04:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D525820652 for ; Wed, 24 Apr 2019 18:04:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556129070; bh=2urUGbbw2oEEE+uqfuNpE9l5FNOKIihSSnlwZxQmq0c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=C3bEqGEGwhRCyn3aurG54g4p2B5SHUHGutGacwMMDTJTBrv+pOH37agjlnmKrI/zq T6RLvWH4mJMnT7SFde3fz0Js6VhWOTr/6NlkvDbIhs5HsXLJkss2otufzp9MbwHLVo OgQfR8ZCOsdvJET93K6dpWeTtCmhB+cASThyEeqc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388962AbfDXRTR (ORCPT ); Wed, 24 Apr 2019 13:19:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:44306 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388147AbfDXRTJ (ORCPT ); Wed, 24 Apr 2019 13:19:09 -0400 Received: from localhost (62-193-50-229.as16211.net [62.193.50.229]) (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 198E421907; Wed, 24 Apr 2019 17:19:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556126347; bh=2urUGbbw2oEEE+uqfuNpE9l5FNOKIihSSnlwZxQmq0c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PZXX4XQCkb18U0X6goDRNPb4ghAgRwLpMki+0Kq7G+njRxuoh1xSxWJCIrout6eBc ytUSoKxQ6EVjCNGVv7iuGPuQnQIsl7kSZ2OtBdTJIlsQtvvhhd8XAjdr/dA6D8mb7s Rvw8GcsOv1avAhTzJuk2bYPz7qBMSKppl8OBQWvM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andrea Righi , Pravin B Shelar , "David S. Miller" Subject: [PATCH 4.4 080/168] openvswitch: fix flow actions reallocation Date: Wed, 24 Apr 2019 19:08:44 +0200 Message-Id: <20190424170928.616999222@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190424170923.452349382@linuxfoundation.org> References: <20190424170923.452349382@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andrea Righi [ Upstream commit f28cd2af22a0c134e4aa1c64a70f70d815d473fb ] The flow action buffer can be resized if it's not big enough to contain all the requested flow actions. However, this resize doesn't take into account the new requested size, the buffer is only increased by a factor of 2x. This might be not enough to contain the new data, causing a buffer overflow, for example: [ 42.044472] ============================================================================= [ 42.045608] BUG kmalloc-96 (Not tainted): Redzone overwritten [ 42.046415] ----------------------------------------------------------------------------- [ 42.047715] Disabling lock debugging due to kernel taint [ 42.047716] INFO: 0x8bf2c4a5-0x720c0928. First byte 0x0 instead of 0xcc [ 42.048677] INFO: Slab 0xbc6d2040 objects=29 used=18 fp=0xdc07dec4 flags=0x2808101 [ 42.049743] INFO: Object 0xd53a3464 @offset=2528 fp=0xccdcdebb [ 42.050747] Redzone 76f1b237: cc cc cc cc cc cc cc cc ........ [ 42.051839] Object d53a3464: 6b 6b 6b 6b 6b 6b 6b 6b 0c 00 00 00 6c 00 00 00 kkkkkkkk....l... [ 42.053015] Object f49a30cc: 6c 00 0c 00 00 00 00 00 00 00 00 03 78 a3 15 f6 l...........x... [ 42.054203] Object acfe4220: 20 00 02 00 ff ff ff ff 00 00 00 00 00 00 00 00 ............... [ 42.055370] Object 21024e91: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 42.056541] Object 070e04c3: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 42.057797] Object 948a777a: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 42.059061] Redzone 8bf2c4a5: 00 00 00 00 .... [ 42.060189] Padding a681b46e: 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ Fix by making sure the new buffer is properly resized to contain all the requested data. BugLink: https://bugs.launchpad.net/bugs/1813244 Signed-off-by: Andrea Righi Acked-by: Pravin B Shelar Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/openvswitch/flow_netlink.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/net/openvswitch/flow_netlink.c +++ b/net/openvswitch/flow_netlink.c @@ -1736,14 +1736,14 @@ static struct nlattr *reserve_sfa_size(s struct sw_flow_actions *acts; int new_acts_size; - int req_size = NLA_ALIGN(attr_len); + size_t req_size = NLA_ALIGN(attr_len); int next_offset = offsetof(struct sw_flow_actions, actions) + (*sfa)->actions_len; if (req_size <= (ksize(*sfa) - next_offset)) goto out; - new_acts_size = ksize(*sfa) * 2; + new_acts_size = max(next_offset + req_size, ksize(*sfa) * 2); if (new_acts_size > MAX_ACTIONS_BUFSIZE) { if ((MAX_ACTIONS_BUFSIZE - next_offset) < req_size) {