From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755194Ab1B1Qg5 (ORCPT ); Mon, 28 Feb 2011 11:36:57 -0500 Received: from kroah.org ([198.145.64.141]:41179 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755165Ab1B1Qgz (ORCPT ); Mon, 28 Feb 2011 11:36:55 -0500 X-Mailbox-Line: From gregkh@clark.kroah.org Mon Feb 28 08:24:06 2011 Message-Id: <20110228162406.273179231@clark.kroah.org> User-Agent: quilt/0.48-11.2 Date: Mon, 28 Feb 2011 08:22:27 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Dan Rosenberg Subject: [06/68] Fix pktcdvd ioctl dev_minor range check In-Reply-To: <20110228163502.GA27221@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let us know. ------------------ From: Dan Rosenberg commit 252a52aa4fa22a668f019e55b3aac3ff71ec1c29 upstream. The PKT_CTRL_CMD_STATUS device ioctl retrieves a pointer to a pktcdvd_device from the global pkt_devs array. The index into this array is provided directly by the user and is a signed integer, so the comparison to ensure that it falls within the bounds of this array will fail when provided with a negative index. This can be used to read arbitrary kernel memory or cause a crash due to an invalid pointer dereference. This can be exploited by users with permission to open /dev/pktcdvd/control (on many distributions, this is readable by group "cdrom"). Signed-off-by: Dan Rosenberg [ Rather than add a cast, just make the function take the right type -Linus ] Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- drivers/block/pktcdvd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/block/pktcdvd.c +++ b/drivers/block/pktcdvd.c @@ -2408,7 +2408,7 @@ static void pkt_release_dev(struct pktcd pkt_shrink_pktlist(pd); } -static struct pktcdvd_device *pkt_find_dev_from_minor(int dev_minor) +static struct pktcdvd_device *pkt_find_dev_from_minor(unsigned int dev_minor) { if (dev_minor >= MAX_WRITERS) return NULL;