From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753205AbeE3LQJ (ORCPT ); Wed, 30 May 2018 07:16:09 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:60672 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751537AbeE3LHY (ORCPT ); Wed, 30 May 2018 07:07:24 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Christoph Hellwig" , "Jens Axboe" , "Dan Carpenter" Date: Wed, 30 May 2018 11:52:41 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 024/153] cdrom: information leak in cdrom_ioctl_media_changed() In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.102-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Dan Carpenter commit 9de4ee40547fd315d4a0ed1dd15a2fa3559ad707 upstream. This cast is wrong. "cdi->capacity" is an int and "arg" is an unsigned long. The way the check is written now, if one of the high 32 bits is set then we could read outside the info->slots[] array. This bug is pretty old and it predates git. Reviewed-by: Christoph Hellwig Signed-off-by: Dan Carpenter Signed-off-by: Jens Axboe Signed-off-by: Ben Hutchings --- drivers/cdrom/cdrom.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/cdrom/cdrom.c +++ b/drivers/cdrom/cdrom.c @@ -2342,7 +2342,7 @@ static int cdrom_ioctl_media_changed(str if (!CDROM_CAN(CDC_SELECT_DISC) || arg == CDSL_CURRENT) return media_changed(cdi, 1); - if ((unsigned int)arg >= cdi->capacity) + if (arg >= cdi->capacity) return -EINVAL; info = kmalloc(sizeof(*info), GFP_KERNEL);