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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AB164C4332F for ; Wed, 2 Mar 2022 20:59:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ABKznocU9FnnmO/5FBSis/ySBaQErFKONq1YlJG77HM=; b=rxxPNaPbUqRLd5 8+vjozxbTA9QftFKP+Eu80soNPJ0AZIDt1xasX0dDtwmfK6yDGfaIpKBw3ADQe5lq1nze7ysXL/rQ 3vvhc6j5XVU/rwP31yUQGVUJn3OLIZRdBdxFDGTI4+AVXbYPaez26yxin5YqYEjGXOUeQ98mEvLln w7fwVp3Kinu9O+C9gKUBFpTjMO68I+pkOhsQ9Z88z4Ro7rVcgr4MuVzHHoXiGA/TnBMdR6fqHpeiG sjqWNKIu8/Uij1tyflQUqx6SqchKl07aK9UVhsozQhK89V5WROpAY7tmO9/0mcDMpRbQmCd2y1gFh 0Hrog9y66OwlYqnX8nkw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nPW4L-00493M-C2; Wed, 02 Mar 2022 20:59:33 +0000 Received: from mail-pg1-x536.google.com ([2607:f8b0:4864:20::536]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nPW4I-00492h-Ll for linux-mediatek@lists.infradead.org; Wed, 02 Mar 2022 20:59:32 +0000 Received: by mail-pg1-x536.google.com with SMTP id o23so2638051pgk.13 for ; Wed, 02 Mar 2022 12:59:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=R/oQqieG0aXWXHs93Td97reRxAIjZoSgBmUtDJFVhjU=; b=d2ZFN7FzXJICmnX4Tyt0wAx0nHny3V7g7RBF7BzoFi4JqvMjvTlFe6r9CSmtZHYpfY sI7cCbacBhQSn0c2nYjk/wWGRSWn9quhJSSynH9lMYRKPPdVW/LYlF+HQ4F3tfS4GoN+ rfxT6gA9HHGJJFfNnOWheyqKpysRyPxkd0f8U= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=R/oQqieG0aXWXHs93Td97reRxAIjZoSgBmUtDJFVhjU=; b=wwkLsjI51eZ1ac1pOxOCGfhP/bCkgKlGc5DBt0iEWFjqq0In9PY49r5BEfXhNcBFWA Xoxureo2sqMV9/VWxoNJZ0DcOe4EiHAZ5ojjQtMRqUAg00n+q4N69nyaxWG88Vdv5vpf RY/pj/c/U8T00t0LwifblsADw36RCB85QSiK9Lo2rE50T5RKukUlL+YF40SEFkSxlC6h pxNjD/KgliyX5ad0FJOrim0vKUo8j1cZnYarOdiix2PhRRxVdzOFS1CswSEg0Ug/09ek wTZSsU60oF0Ku+u3EpuIp//g3aEsC2YLbVxKtGy/f1tHFg4Yyz/gWmxHjHxfc4KZ8np7 CPlg== X-Gm-Message-State: AOAM533UNIx87Kf5s3M5dFwrJHP8AKHxCSnS2W3Q7aByyAhItLc2RO5n 9M0K4egE9a95aBCZ5B6+FypVLg== X-Google-Smtp-Source: ABdhPJwV5Vftpu3BNFYOd1YAI3xcgBfQbmCq2DPnKYT59xnVma61vCMoUamoUdgwMbiUWTPibOctJw== X-Received: by 2002:a63:595e:0:b0:378:b203:a74e with SMTP id j30-20020a63595e000000b00378b203a74emr13280856pgm.328.1646254769698; Wed, 02 Mar 2022 12:59:29 -0800 (PST) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id z9-20020a655a49000000b00373459df190sm58337pgs.35.2022.03.02.12.59.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 02 Mar 2022 12:59:29 -0800 (PST) Date: Wed, 2 Mar 2022 12:59:28 -0800 From: Kees Cook To: Linus Torvalds Cc: Rasmus Villemoes , David Laight , James Bottomley , linux-wireless , "alsa-devel@alsa-project.org" , KVM list , "Gustavo A. R. Silva" , "linux-iio@vger.kernel.org" , "nouveau@lists.freedesktop.org" , dri-devel , Cristiano Giuffrida , "Bos, H.J." , "linux1394-devel@lists.sourceforge.net" , "drbd-dev@lists.linbit.com" , linux-arch , CIFS , "linux-aspeed@lists.ozlabs.org" , linux-scsi , linux-rdma , "linux-staging@lists.linux.dev" , amd-gfx list , Jason Gunthorpe , "intel-wired-lan@lists.osuosl.org" , "kgdb-bugreport@lists.sourceforge.net" , "bcm-kernel-feedback-list@broadcom.com" , Dan Carpenter , Linux Media Mailing List , Arnd Bergman , Linux PM , intel-gfx , Brian Johannesmeyer , Nathan Chancellor , dma , Christophe JAILLET , Jakob Koschel , "v9fs-developer@lists.sourceforge.net" , linux-tegra , Thomas Gleixner , Andy Shevchenko , Linux ARM , "linux-sgx@vger.kernel.org" , linux-block , Netdev , "linux-usb@vger.kernel.org" , "samba-technical@lists.samba.org" , Linux Kernel Mailing List , Linux F2FS Dev Mailing List , "tipc-discussion@lists.sourceforge.net" , Linux Crypto Mailing List , linux-fsdevel , "linux-mediatek@lists.infradead.org" , Andrew Morton , linuxppc-dev , Christian =?iso-8859-1?Q?K=F6nig?= , Mike Rapoport Subject: Re: [PATCH 2/6] treewide: remove using list iterator after loop body as a ptr Message-ID: <202203021256.69D7C4BCA6@keescook> References: <7D0C2A5D-500E-4F38-AD0C-A76E132A390E@kernel.org> <73fa82a20910c06784be2352a655acc59e9942ea.camel@HansenPartnership.com> <7dc860874d434d2288f36730d8ea3312@AcuMS.aculab.com> <0ced2b155b984882b39e895f0211037c@AcuMS.aculab.com> <78ccb184-405e-da93-1e02-078f90d2b9bc@rasmusvillemoes.dk> <202203021158.DB5204A0@keescook> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220302_125930_750124_D7CC7F7E X-CRM114-Status: GOOD ( 18.16 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org On Wed, Mar 02, 2022 at 12:18:45PM -0800, Linus Torvalds wrote: > On Wed, Mar 2, 2022 at 12:07 PM Kees Cook wrote: > > > > I've long wanted to change kfree() to explicitly set pointers to NULL on > > free. https://github.com/KSPP/linux/issues/87 > > We've had this discussion with the gcc people in the past, and gcc > actually has some support for it, but it's sadly tied to the actual > function name (ie gcc has some special-casing for "free()") > > See > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94527 > > for some of that discussion. > > Oh, and I see some patch actually got merged since I looked there last > so that you can mark "deallocator" functions, but I think it's only > for the context matching, not for actually killing accesses to the > pointer afterwards. Ah! I missed that getting added in GCC 11. But yes, there it is: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-malloc-function-attribute Hah, now we may need to split __malloc from __alloc_size. ;) I'd still like the NULL assignment behavior, though, since some things can easily avoid static analysis. -- Kees Cook _______________________________________________ Linux-mediatek mailing list Linux-mediatek@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-mediatek