From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750961AbdE1HxT (ORCPT ); Sun, 28 May 2017 03:53:19 -0400 Received: from bombadil.infradead.org ([65.50.211.133]:59507 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750890AbdE1HxR (ORCPT ); Sun, 28 May 2017 03:53:17 -0400 Date: Sun, 28 May 2017 00:53:13 -0700 From: Christoph Hellwig To: Kees Cook Cc: kernel-hardening@lists.openwall.com, Laura Abbott , x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 01/20] NFS: Avoid cross-structure casting Message-ID: <20170528075313.GB22193@infradead.org> References: <1495829844-69341-1-git-send-email-keescook@chromium.org> <1495829844-69341-2-git-send-email-keescook@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1495829844-69341-2-git-send-email-keescook@chromium.org> User-Agent: Mutt/1.8.0 (2017-02-23) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 26, 2017 at 01:17:05PM -0700, Kees Cook wrote: > When the call to nfs_devname() fails, the error path attempts to retain > the error via the mnt variable, but this requires a cast across very > different types (char * to struct vfsmount *), which the upcoming > structure layout randomization plugin flags as being potentially > dangerous in the face of randomization. This is a false positive, but > what this code actually wants to do is retain the error value, so this > patch explicitly sets it, instead of using what seems to be an > unexpected cast. > > Signed-off-by: Kees Cook > Acked-by: Trond Myklebust Looks good: Reviewed-by: Christoph Hellwig And I think we should get this (and the other cast patches) in ASAP, independent of the fat of the randstruct plugin.