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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 735B3C433F5 for ; Wed, 6 Oct 2021 01:47:24 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 071AA61269 for ; Wed, 6 Oct 2021 01:47:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 071AA61269 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 1E2266B006C; Tue, 5 Oct 2021 21:47:23 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 191E86B0071; Tue, 5 Oct 2021 21:47:23 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0810B900002; Tue, 5 Oct 2021 21:47:23 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0234.hostedemail.com [216.40.44.234]) by kanga.kvack.org (Postfix) with ESMTP id EB1196B006C for ; Tue, 5 Oct 2021 21:47:22 -0400 (EDT) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id A0B801836942E for ; Wed, 6 Oct 2021 01:47:22 +0000 (UTC) X-FDA: 78664325124.21.74F5AF7 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf06.hostedemail.com (Postfix) with ESMTP id 5B633801BEF6 for ; Wed, 6 Oct 2021 01:47:22 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 9D00A611CC; Wed, 6 Oct 2021 01:47:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1633484838; bh=Xt+wZ6PkpbqGmpCET0SN48ylqvwvPAINuGHGp2TK1uY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=IxA2DMOOXNCn02Sbwsru0IXmgNMs9rv4nMcyqr06+2YctzkpKzNPO6CCXPdKM1Np0 t7lmbu0FEO37bLus65CjV0G166hksDhs7XFigmUyv4IM9aFkaL9zjCRpK2rOMsWEqX EkL6cytWknEjtB//VUBv0jEX19efvyxzhNHUIrns= Date: Tue, 5 Oct 2021 18:47:17 -0700 From: Andrew Morton To: Kees Cook Cc: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Vlastimil Babka , Andy Whitcroft , Dennis Zhou , Dwaipayan Ray , Joe Perches , Lukas Bulwahn , Miguel Ojeda , Nathan Chancellor , Tejun Heo , Daniel Micay , Nick Desaulniers , Masahiro Yamada , Michal Marek , clang-built-linux@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH v3 4/8] slab: Add __alloc_size attributes for better bounds checking Message-Id: <20211005184717.65c6d8eb39350395e387b71f@linux-foundation.org> In-Reply-To: <20210930222704.2631604-5-keescook@chromium.org> References: <20210930222704.2631604-1-keescook@chromium.org> <20210930222704.2631604-5-keescook@chromium.org> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 5B633801BEF6 X-Stat-Signature: tj4f8nwac1n61njt549o8ek97a1hpuwc Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=IxA2DMOO; dmarc=none; spf=pass (imf06.hostedemail.com: domain of akpm@linux-foundation.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org X-HE-Tag: 1633484842-107882 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, 30 Sep 2021 15:27:00 -0700 Kees Cook wrote: > As already done in GrapheneOS, add the __alloc_size attribute for regular > kmalloc interfaces, to provide additional hinting for better bounds > checking, assisting CONFIG_FORTIFY_SOURCE and other compiler > optimizations. x86_64 allmodconfig: In file included from ./arch/x86/include/asm/preempt.h:7, from ./include/linux/preempt.h:78, from ./include/linux/spinlock.h:55, from ./include/linux/mmzone.h:8, from ./include/linux/gfp.h:6, from ./include/linux/mm.h:10, from ./include/linux/mman.h:5, from lib/test_kasan_module.c:10: In function 'check_copy_size', inlined from 'copy_user_test' at ./include/linux/uaccess.h:191:6: ./include/linux/thread_info.h:213:4: error: call to '__bad_copy_to' declared with attribute error: copy destination size is too small 213 | __bad_copy_to(); | ^~~~~~~~~~~~~~~ In function 'check_copy_size', inlined from 'copy_user_test' at ./include/linux/uaccess.h:199:6: ./include/linux/thread_info.h:211:4: error: call to '__bad_copy_from' declared with attribute error: copy source size is too small 211 | __bad_copy_from(); | ^~~~~~~~~~~~~~~~~ make[1]: *** [lib/test_kasan_module.o] Error 1 make: *** [lib] Error 2