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 X-Spam-Level: X-Spam-Status: No, score=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 BA4BEC433E4 for ; Fri, 10 Jul 2020 22:05:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8C53F2065F for ; Fri, 10 Jul 2020 22:05:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Gf95zy8J" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726314AbgGJWE7 (ORCPT ); Fri, 10 Jul 2020 18:04:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57808 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726261AbgGJWE7 (ORCPT ); Fri, 10 Jul 2020 18:04:59 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D3A84C08C5DC; Fri, 10 Jul 2020 15:04:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=Sm08KILQrIhAFoGlCB+I5zhmi1eIMEDSey/M3AAwvrU=; b=Gf95zy8J04apBo9wUZ1mnOjWys Q3E03aUJHod0cOCoGZfdB++6r3mBBHEKatQ07qkf93nEwhMrFMsQ2Ca/R1uwDGBQtByztdqV22DbK MbowX9JA/4O7y2NTMT32X7ukvtTKvL4/tDSchahf7/ARoWtxtGK3tAyFycxBMjF07h2aGRzNfDyBF 896zhV0TFTjt1H9YL00Om/6oR87oi92+QAYOnGSnDR68RuREB5bOdQ0YbsY7JcalooY6BII+0YORf A/9yXRmMifrzgpx+7GSxIYeCBTW8H9j9HVFaCoB1CvgXqNlUuS9P0V4JDL+gHl0AwbpanQyn4Gw33 z3h2bHmQ==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1ju17r-0000Yi-Ej; Fri, 10 Jul 2020 22:04:11 +0000 Date: Fri, 10 Jul 2020 23:04:11 +0100 From: Matthew Wilcox To: Scott Branden Cc: Kees Cook , James Morris , Luis Chamberlain , Mimi Zohar , Greg Kroah-Hartman , "Rafael J. Wysocki" , Alexander Viro , Jessica Yu , Dmitry Kasatkin , "Serge E. Hallyn" , Casey Schaufler , "Eric W. Biederman" , Peter Zijlstra , Matthew Garrett , David Howells , Mauro Carvalho Chehab , Randy Dunlap , "Joel Fernandes (Google)" , KP Singh , Dave Olsthoorn , Hans de Goede , Peter Jones , Andrew Morton , Stephen Boyd , Paul Moore , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org Subject: Re: [PATCH 2/4] fs: Remove FIRMWARE_PREALLOC_BUFFER from kernel_read_file() enums Message-ID: <20200710220411.GR12769@casper.infradead.org> References: <20200707081926.3688096-1-keescook@chromium.org> <20200707081926.3688096-3-keescook@chromium.org> <3fdb3c53-7471-14d8-ce6a-251d8b660b8a@broadcom.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3fdb3c53-7471-14d8-ce6a-251d8b660b8a@broadcom.com> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Fri, Jul 10, 2020 at 02:00:32PM -0700, Scott Branden wrote: > > @@ -950,8 +951,8 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size, > > goto out; > > } > > - if (id != READING_FIRMWARE_PREALLOC_BUFFER) > > - *buf = vmalloc(i_size); > > + if (!*buf) > The assumption that *buf is always NULL when id != > READING_FIRMWARE_PREALLOC_BUFFER doesn't appear to be correct. > I get unhandled page faults due to this change on boot. Did it give you a stack backtrace?