From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752359Ab3J2XTs (ORCPT ); Tue, 29 Oct 2013 19:19:48 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:39734 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751693Ab3J2XTq (ORCPT ); Tue, 29 Oct 2013 19:19:46 -0400 Date: Tue, 29 Oct 2013 16:19:45 -0700 From: Greg KH To: Tomas Winkler Cc: arnd@arndb.de, linux-kernel@vger.kernel.org Subject: Re: [char-misc-next 2/8] mei: hbm: validate client index is not exceeding allocated array size Message-ID: <20131029231945.GB30410@kroah.com> References: <1382382343-12066-1-git-send-email-tomas.winkler@intel.com> <1382382343-12066-3-git-send-email-tomas.winkler@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1382382343-12066-3-git-send-email-tomas.winkler@intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 21, 2013 at 10:05:37PM +0300, Tomas Winkler wrote: > Signed-off-by: Tomas Winkler > --- > drivers/misc/mei/hbm.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/misc/mei/hbm.c b/drivers/misc/mei/hbm.c > index 9b3a0fb..0f5e8ca 100644 > --- a/drivers/misc/mei/hbm.c > +++ b/drivers/misc/mei/hbm.c > @@ -228,8 +228,6 @@ static int mei_hbm_prop_req(struct mei_device *dev) > unsigned long client_num; > > > - client_num = dev->me_client_presentation_num; > - > next_client_index = find_next_bit(dev->me_clients_map, MEI_CLIENTS_MAX, > dev->me_client_index); > > @@ -241,6 +239,10 @@ static int mei_hbm_prop_req(struct mei_device *dev) > return 0; > } > > + client_num = dev->me_client_presentation_num; > + if (WARN_ON(dev->me_clients_num <= client_num)) > + return -EIO; How can this happen? Why is spitting out a huge warning in the syslog going to help anything? If a user can do this, then great, now you can DoS your syslog :( If a user can't do this, then why tell them, it's your driver's bug that you should just fix. greg k-h