From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752141AbbIQMxG (ORCPT ); Thu, 17 Sep 2015 08:53:06 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:43600 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751059AbbIQMxC (ORCPT ); Thu, 17 Sep 2015 08:53:02 -0400 Date: Thu, 17 Sep 2015 05:53:01 -0700 From: Greg KH To: Dmitry Vyukov Cc: peter@hurleysoftware.com, jslaby@suse.com, linux-kernel@vger.kernel.org, jslaby@suse.cz, andreyknvl@google.com, kcc@google.com, glider@google.com, paulmck@linux.vnet.ibm.com, hboehm@google.com Subject: Re: [PATCH v2] tty: fix data race in flush_to_ldisc Message-ID: <20150917125301.GB16085@kroah.com> References: <1442486376-115369-1-git-send-email-dvyukov@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1442486376-115369-1-git-send-email-dvyukov@google.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 17, 2015 at 12:39:36PM +0200, Dmitry Vyukov wrote: > flush_to_ldisc reads port->itty and checks that it is not NULL, > concurrently release_tty sets port->itty to NULL. It is possible > that flush_to_ldisc loads port->itty once, ensures that it is > not NULL, but then reloads it again and uses. The second load > can already return NULL, which will cause a crash. > > Use READ_ONCE to read port->itty. > > The data race was found with KernelThreadSanitizer (KTSAN). > > Signed-off-by: Dmitry Vyukov You sent 3 patches here, but no hint as to what order they need to be applied in. Please resend them as a patch series (i.e. 1/3, 2/3, 3/3) so they can be applied correctly. thanks, greg k-h