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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8D290C6FA91 for ; Fri, 16 Sep 2022 08:07:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229657AbiIPIHp (ORCPT ); Fri, 16 Sep 2022 04:07:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51326 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230077AbiIPIHb (ORCPT ); Fri, 16 Sep 2022 04:07:31 -0400 Received: from mail-pj1-x102b.google.com (mail-pj1-x102b.google.com [IPv6:2607:f8b0:4864:20::102b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4C2573CBD4 for ; Fri, 16 Sep 2022 01:07:28 -0700 (PDT) Received: by mail-pj1-x102b.google.com with SMTP id s14-20020a17090a6e4e00b0020057c70943so24903617pjm.1 for ; Fri, 16 Sep 2022 01:07:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date; bh=efUD2Cuze1s5fu9A1+CyDLPrdcU/1Kt0bMyNsDXEONY=; b=Jn15m+vFx5hwwmK/xwXR0sCWR0XgV3QsV7ccaNanOuS/M5Ti8PPipPZMdKd5Y+zJPm GgXlNWlpvOr8dd+Nb4+atVVBoPlkS/Z0RcXfqXlur5FPEaxE9Aot2NLQkXBkqR5fxknU qcmU1d4BLDOM6yeo8L7ir66kaxwPHgSV4WzQg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date; bh=efUD2Cuze1s5fu9A1+CyDLPrdcU/1Kt0bMyNsDXEONY=; b=sC3zZwivdWJPiPFymLTiTfh746Oy/Rt6r0hQXcnqZP+Y6fT7WQYYiq/dQfF9JC4P3/ 60sod3yL9rT0bZo9lFM5dEEfEdzO9cScZOR+sfQSlNEQ1wbQagIzBhg0Am1Kp8L2bas4 nM41/fN7AZ5D04Tkcj4YR3S/KB7RMCZEjPmmBwUgtTKHWbmUwIHZO8PFyr1B31hXOiSV /r/Xrxk9hek0gLBKMeCgdZdC4nnDyX4wigs3kWne2QWtsPFL3fsWWI8G55yjirip10Qh +OZGccJrUzILX1/8Q4Lw5wKiBP0RVCfFkncnWrH2Uree0TQbk/CblcZhVhJWtUX3hnb6 rJvw== X-Gm-Message-State: ACrzQf2ob0jgAH8/n29r5XDdmku3NMVi1PRkdhgEf1ztgGhFdbPdYMPc Gak2eVGtPdz9FUJa1fIjWB+yRA== X-Google-Smtp-Source: AMsMyM4/znlazRwzEOVAPXReEX1A/RlzXSzwHTL4q0v6nu4NImq0p3KAUU2ExLKgahX4HV+lsKBNJA== X-Received: by 2002:a17:90b:3a8e:b0:200:5585:4099 with SMTP id om14-20020a17090b3a8e00b0020055854099mr15554975pjb.70.1663315647392; Fri, 16 Sep 2022 01:07:27 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id e1-20020a17090301c100b0017828ae6310sm11876407plh.2.2022.09.16.01.07.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 16 Sep 2022 01:07:26 -0700 (PDT) Date: Fri, 16 Sep 2022 01:07:25 -0700 From: Kees Cook To: Dan Carpenter Cc: "Gustavo A. R. Silva" , Peter Rosin , Wolfram Sang , "Gustavo A. R. Silva" , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH] i2c: mux: harden i2c_mux_alloc() against integer overflows Message-ID: <202209160101.2A240E9@keescook> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 15, 2022 at 05:09:45PM +0300, Dan Carpenter wrote: > It would probaby be useful to mark passed data as explicitly unsafe for > integer overflows. Smatch already tracks user data. And if the user > data has been capped to an unknown value. But this would be a > completely separate flag which says that "this value came from > size_add/mul()". I really want a __must_check_type(size_t) attribute or something for functions, so we can get a subset of -Wconversion warnings, etc. > drivers/char/tpm/eventlog/tpm2.c:57 tpm2_bios_measurements_start() warn: using integer overflow function 'size_add()' for math > [...] > drivers/net/ethernet/intel/ice/ice_flex_pipe.c:2070 ice_pkg_buf_reserve_section() warn: using integer overflow function 'size_mul()' for math I see size_add() and size_mul() here. I would have expected some size_sub() opportunities too? Did nothing pop out? -- Kees Cook