Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Fri, 8 May 2020 22:33:51 -0700
From:   Kees Cook <keescook@chromium.org>
To:     "Eric W. Biederman" <ebiederm@xmission.com>
Cc:     linux-kernel@vger.kernel.org,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Oleg Nesterov <oleg@redhat.com>, Jann Horn <jannh@google.com>,
        Greg Ungerer <gerg@linux-m68k.org>,
        Rob Landley <rob@landley.net>,
        Bernd Edlinger <bernd.edlinger@hotmail.de>,
        linux-fsdevel@vger.kernel.org, Al Viro <viro@ZenIV.linux.org.uk>,
        Alexey Dobriyan <adobriyan@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH 6/6] exec: Set the point of no return sooner
Message-ID: <202005082232.59838F2@keescook>
References: <87h7wujhmz.fsf@x220.int.ebiederm.org>
 <87sgga6ze4.fsf@x220.int.ebiederm.org>
 <87sgga5klu.fsf_-_@x220.int.ebiederm.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <87sgga5klu.fsf_-_@x220.int.ebiederm.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Fri, May 08, 2020 at 01:48:13PM -0500, Eric W. Biederman wrote:
> 
> Make the code more robust by marking the point of no return sooner.
> This ensures that future code changes don't need to worry about how
> they return errors if they are past this point.
> 
> This results in no actual change in behavior as __do_execve_file does
> not force SIGSEGV when there is a pending fatal signal pending past
> the point of no return.  Further the only error returns from de_thread
> and exec_mmap that can occur result in fatal signals being pending.
> 
> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

Yes, thank you. I'm a fan; this makes the comment above the function a
bit easier to understand, since the very first thing is to set the
point_of_no_return. :)

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook