From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757200Ab2HOU21 (ORCPT ); Wed, 15 Aug 2012 16:28:27 -0400 Received: from mail1.windriver.com ([147.11.146.13]:62849 "EHLO mail1.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756457Ab2HOTuE (ORCPT ); Wed, 15 Aug 2012 15:50:04 -0400 From: Paul Gortmaker To: , CC: Peter Huewe , Rajiv Andrade , James Morris , Paul Gortmaker Subject: [v2.6.34-stable 050/165] TPM: Zero buffer after copying to userspace Date: Wed, 15 Aug 2012 15:46:34 -0400 Message-ID: <1345060109-9187-51-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.12.rc2 In-Reply-To: <1345060109-9187-1-git-send-email-paul.gortmaker@windriver.com> References: <1345060109-9187-1-git-send-email-paul.gortmaker@windriver.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peter Huewe ------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. ------------------- commit 3321c07ae5068568cd61ac9f4ba749006a7185c9 upstream. Since the buffer might contain security related data it might be a good idea to zero the buffer after we have copied it to userspace. This got assigned CVE-2011-1162. Signed-off-by: Rajiv Andrade Signed-off-by: James Morris Signed-off-by: Paul Gortmaker --- drivers/char/tpm/tpm.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c index f39e5ee..9fe4683 100644 --- a/drivers/char/tpm/tpm.c +++ b/drivers/char/tpm/tpm.c @@ -1031,6 +1031,7 @@ ssize_t tpm_read(struct file *file, char __user *buf, { struct tpm_chip *chip = file->private_data; ssize_t ret_size; + int rc; del_singleshot_timer_sync(&chip->user_read_timer); flush_scheduled_work(); @@ -1041,8 +1042,11 @@ ssize_t tpm_read(struct file *file, char __user *buf, ret_size = size; mutex_lock(&chip->buffer_mutex); - if (copy_to_user(buf, chip->data_buffer, ret_size)) + rc = copy_to_user(buf, chip->data_buffer, ret_size); + memset(chip->data_buffer, 0, ret_size); + if (rc) ret_size = -EFAULT; + mutex_unlock(&chip->buffer_mutex); } -- 1.7.12.rc2