From patchwork Fri Feb 5 17:53:52 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Colin King X-Patchwork-Id: 377446 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, 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 2D028C433DB for ; Fri, 5 Feb 2021 17:57:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D303E64E2E for ; Fri, 5 Feb 2021 17:57:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233614AbhBEQOd (ORCPT ); Fri, 5 Feb 2021 11:14:33 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:39774 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233603AbhBEQMR (ORCPT ); Fri, 5 Feb 2021 11:12:17 -0500 Received: from 1.general.cking.uk.vpn ([10.172.193.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1l85Im-0004k3-Ez; Fri, 05 Feb 2021 17:53:52 +0000 From: Colin King To: Johannes Berg , "David S . Miller" , Jakub Kicinski , "John W . Linville" , Luis Carlos Cobo , linux-wireless@vger.kernel.org, netdev@vger.kernel.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] mac80211: fix potential overflow when multiplying to u32 integers Date: Fri, 5 Feb 2021 17:53:52 +0000 Message-Id: <20210205175352.208841-1-colin.king@canonical.com> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Colin Ian King The multiplication of the u32 variables tx_time and estimated_retx is performed using a 32 bit multiplication and the result is stored in a u64 result. This has a potential u32 overflow issue, so avoid this by casting tx_time to a u64 to force a 64 bit multiply. Addresses-Coverity: ("Unintentional integer overflow") Fixes: 050ac52cbe1f ("mac80211: code for on-demand Hybrid Wireless Mesh Protocol") Signed-off-by: Colin Ian King --- net/mac80211/mesh_hwmp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c index 313eee12410e..3db514c4c63a 100644 --- a/net/mac80211/mesh_hwmp.c +++ b/net/mac80211/mesh_hwmp.c @@ -356,7 +356,7 @@ u32 airtime_link_metric_get(struct ieee80211_local *local, */ tx_time = (device_constant + 10 * test_frame_len / rate); estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err)); - result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT); + result = ((u64)tx_time * estimated_retx) >> (2 * ARITH_SHIFT); return (u32)result; }