From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:47446 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932906AbeD0OAP (ORCPT ); Fri, 27 Apr 2018 10:00:15 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christoph Hellwig , Dan Carpenter , Jens Axboe Subject: [PATCH 3.18 24/24] cdrom: information leak in cdrom_ioctl_media_changed() Date: Fri, 27 Apr 2018 15:57:59 +0200 Message-Id: <20180427135632.574634449@linuxfoundation.org> In-Reply-To: <20180427135631.584839868@linuxfoundation.org> References: <20180427135631.584839868@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 3.18-stable 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 Cc: stable@vger.kernel.org Signed-off-by: Dan Carpenter Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- drivers/cdrom/cdrom.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/cdrom/cdrom.c +++ b/drivers/cdrom/cdrom.c @@ -2357,7 +2357,7 @@ 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);