From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933451Ab1I1Wtj (ORCPT ); Wed, 28 Sep 2011 18:49:39 -0400 Received: from cantor2.suse.de ([195.135.220.15]:54932 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933424Ab1I1Wt3 (ORCPT ); Wed, 28 Sep 2011 18:49:29 -0400 X-Mailbox-Line: From gregkh@clark.kroah.org Wed Sep 28 15:01:45 2011 Message-Id: <20110928220145.699470650@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Wed, 28 Sep 2011 15:02:37 -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, Rajiv Andrade , James Morris Subject: [193/244] TPM: Zero buffer after copying to userspace In-Reply-To: <20110928220225.GA27128@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.0-stable review patch. If anyone has any objections, please let us know. ------------------ From: Peter Huewe 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: Greg Kroah-Hartman --- drivers/char/tpm/tpm.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/drivers/char/tpm/tpm.c +++ b/drivers/char/tpm/tpm.c @@ -1055,6 +1055,7 @@ ssize_t tpm_read(struct file *file, char { struct tpm_chip *chip = file->private_data; ssize_t ret_size; + int rc; del_singleshot_timer_sync(&chip->user_read_timer); flush_work_sync(&chip->work); @@ -1065,8 +1066,11 @@ ssize_t tpm_read(struct file *file, char 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); }