From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932817Ab1EFAvV (ORCPT ); Thu, 5 May 2011 20:51:21 -0400 Received: from kroah.org ([198.145.64.141]:36917 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932297Ab1EFAZI (ORCPT ); Thu, 5 May 2011 20:25:08 -0400 X-Mailbox-Line: From gregkh@clark.kroah.org Thu May 5 17:22:12 2011 Message-Id: <20110506002212.189011971@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Thu, 05 May 2011 17:20:56 -0700 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, Timo Warns Subject: [071/143] Fix corrupted OSF partition table parsing In-Reply-To: <20110506002311.GA15354@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: Timo Warns commit 1eafbfeb7bdf59cfe173304c76188f3fd5f1fd05 upstream. The kernel automatically evaluates partition tables of storage devices. The code for evaluating OSF partitions contains a bug that leaks data from kernel heap memory to userspace for certain corrupted OSF partitions. In more detail: for (i = 0 ; i < le16_to_cpu(label->d_npartitions); i++, partition++) { iterates from 0 to d_npartitions - 1, where d_npartitions is read from the partition table without validation and partition is a pointer to an array of at most 8 d_partitions. Add the proper and obvious validation. Signed-off-by: Timo Warns Cc: stable@kernel.org [ Changed the patch trivially to not repeat the whole le16_to_cpu() thing, and to use an explicit constant for the magic value '8' ] Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/partitions/osf.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) --- a/fs/partitions/osf.c +++ b/fs/partitions/osf.c @@ -10,10 +10,13 @@ #include "check.h" #include "osf.h" +#define MAX_OSF_PARTITIONS 8 + int osf_partition(struct parsed_partitions *state, struct block_device *bdev) { int i; int slot = 1; + unsigned int npartitions; Sector sect; unsigned char *data; struct disklabel { @@ -45,7 +48,7 @@ int osf_partition(struct parsed_partitio u8 p_fstype; u8 p_frag; __le16 p_cpg; - } d_partitions[8]; + } d_partitions[MAX_OSF_PARTITIONS]; } * label; struct d_partition * partition; @@ -63,7 +66,12 @@ int osf_partition(struct parsed_partitio put_dev_sector(sect); return 0; } - for (i = 0 ; i < le16_to_cpu(label->d_npartitions); i++, partition++) { + npartitions = le16_to_cpu(label->d_npartitions); + if (npartitions > MAX_OSF_PARTITIONS) { + put_dev_sector(sect); + return 0; + } + for (i = 0 ; i < npartitions; i++, partition++) { if (slot == state->limit) break; if (le32_to_cpu(partition->p_size))