From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750855AbdE1Qzk (ORCPT ); Sun, 28 May 2017 12:55:40 -0400 Received: from mail-io0-f172.google.com ([209.85.223.172]:35596 "EHLO mail-io0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750784AbdE1Qzj (ORCPT ); Sun, 28 May 2017 12:55:39 -0400 MIME-Version: 1.0 In-Reply-To: <20170528075313.GB22193@infradead.org> References: <1495829844-69341-1-git-send-email-keescook@chromium.org> <1495829844-69341-2-git-send-email-keescook@chromium.org> <20170528075313.GB22193@infradead.org> From: Kees Cook Date: Sun, 28 May 2017 09:55:37 -0700 X-Google-Sender-Auth: yVTgn5lyE2NtSkpGL9Sl-rum-R0 Message-ID: Subject: Re: [PATCH v2 01/20] NFS: Avoid cross-structure casting To: Christoph Hellwig Cc: "kernel-hardening@lists.openwall.com" , Laura Abbott , "x86@kernel.org" , LKML Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, May 28, 2017 at 12:53 AM, Christoph Hellwig wrote: > 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. Should I send a pull request to Linus for these for v4.12? -Kees -- Kees Cook Pixel Security