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 3D6E1C433F5 for ; Mon, 23 May 2022 19:43:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230388AbiEWTnR (ORCPT ); Mon, 23 May 2022 15:43:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38914 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234006AbiEWTmT (ORCPT ); Mon, 23 May 2022 15:42:19 -0400 Received: from mail-pl1-x62c.google.com (mail-pl1-x62c.google.com [IPv6:2607:f8b0:4864:20::62c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D67AC11C20 for ; Mon, 23 May 2022 12:39:15 -0700 (PDT) Received: by mail-pl1-x62c.google.com with SMTP id q4so13982708plr.11 for ; Mon, 23 May 2022 12:39:15 -0700 (PDT) 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=9i0mf5EWjId+dJhDG42zI0t8gO1U5xR/fPTtg8h/guQ=; b=G67mgEOcbKAzzfRqWT2tyqM6K9pitcq9pbTVcwT0LjmKZNi0oiqVsX8V97hEFwl2hf AMnpF3tfbp0thJvNCE4CX5dI4O8ELTGwmxs1K5fhCNP737yCqZGbfIr/xW9c33Xf+LOK scdJ+18kS7hWnfRSUS9ItgijmeteaopgZF3uU= 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=9i0mf5EWjId+dJhDG42zI0t8gO1U5xR/fPTtg8h/guQ=; b=hatTxjc4Sd9LYYfof09Y3MooL1wN8ROHEgZdZBoAMHnEMKHBTgjGIk/EdozaAYNodD ei1C8ZnIpnZYl0rysdFEX3XcHd5keMnRLJ7cuZ0oQG1oBGv1vLTV9avNS7NvE4fB3RxJ WWWZemKWdQssWvpkX2bJmU7u3vwfvz2EcwFlkGqWn9iDPB7BU8Y8CsBApKlkJObVzTCg DeSUoDOmm0avSALS1lC8ob78INr5bs5r7nhblxm3XORQq83YN3d6sU57vIzBMSREos+r YjJQqeDrZHdXJVh64MgKPUeyYFVWV1mK2kR8zs7W+cm4R5X7lik68efbbcgbz27bv/ry yfTg== X-Gm-Message-State: AOAM531arTjwMybu79tCPoEJhGK7MB3ysKnMCqo1abpWTjGvPsVsNHPl cRU3X5FZeKnfrnUAuNGYB+t4yw== X-Google-Smtp-Source: ABdhPJwpmlrfLvCqOEAWUHk/iFb9vTBCFvDV+XiSslGuIShWmQMdDaruCMB2aTz4o4uZEjpK38rAug== X-Received: by 2002:a17:902:f605:b0:14d:9e11:c864 with SMTP id n5-20020a170902f60500b0014d9e11c864mr24236615plg.54.1653334755308; Mon, 23 May 2022 12:39:15 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id a9-20020a62bd09000000b0051827128aeasm7543246pff.131.2022.05.23.12.39.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 23 May 2022 12:39:14 -0700 (PDT) Date: Mon, 23 May 2022 12:39:12 -0700 From: Kees Cook To: Christoph Hellwig Cc: Maninder Singh , pmladek@suse.com, bcain@quicinc.com, mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, borntraeger@linux.ibm.com, svens@linux.ibm.com, satishkh@cisco.com, sebaddel@cisco.com, kartilak@cisco.com, jejb@linux.ibm.com, martin.petersen@oracle.com, mcgrof@kernel.org, jason.wessel@windriver.com, daniel.thompson@linaro.org, dianders@chromium.org, naveen.n.rao@linux.ibm.com, anil.s.keshavamurthy@intel.com, davem@davemloft.net, mhiramat@kernel.org, peterz@infradead.org, mingo@redhat.com, will@kernel.org, longman@redhat.com, boqun.feng@gmail.com, rostedt@goodmis.org, senozhatsky@chromium.org, andriy.shevchenko@linux.intel.com, linux@rasmusvillemoes.dk, akpm@linux-foundation.org, arnd@arndb.de, linux-hexagon@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-modules@vger.kernel.org, kgdb-bugreport@lists.sourceforge.net, v.narang@samsung.com, onkarnath.1@samsung.com Subject: Re: [PATCH 0/5] kallsyms: make kallsym APIs more safe with scnprintf Message-ID: <202205231238.FAF6D28@keescook> References: <20220520083701.2610975-1-maninder1.s@samsung.com> 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-fsdevel@vger.kernel.org On Sat, May 21, 2022 at 11:07:52PM -0700, Christoph Hellwig wrote: > On Fri, May 20, 2022 at 02:06:56PM +0530, Maninder Singh wrote: > > kallsyms functionality depends on KSYM_NAME_LEN directly. > > but if user passed array length lesser than it, sprintf > > can cause issues of buffer overflow attack. > > > > So changing *sprint* and *lookup* APIs in this patch set > > to have buffer size as an argument and replacing sprintf with > > scnprintf. > > This is still a pretty horrible API. Passing something like > a struct seq_buf seems like the much better API here. Also with > the amount of arguments and by reference passing it might be worth > to pass them as a structure while you're at it. Yeah, I agree. It really seems like seq_buf would be nicer. -- Kees Cook