From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755610AbcITRZe (ORCPT ); Tue, 20 Sep 2016 13:25:34 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:57631 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754743AbcITRZd (ORCPT ); Tue, 20 Sep 2016 13:25:33 -0400 From: Colin King To: Mimi Zohar , James Morris , "Serge E . Hallyn" , linux-ima-devel@lists.sourceforge.net, linux-ima-user@lists.sourceforge.net, linux-security-module@vger.kernel.org Cc: linux-kernel@vger.kernel.org Subject: [PATCH] ima: fix off-by-one comparison on template name length Date: Tue, 20 Sep 2016 18:25:27 +0100 Message-Id: <20160920172527.23849-1-colin.king@canonical.com> X-Mailer: git-send-email 2.9.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Colin Ian King The comparison of dr_v1->template_name_len is off-by-one, so currently if the length is MAX_TEMPLATE_NAME_LEN we end up with an out-of-bounds write on template_name when the terminating zero character is written. Fix the comparison. Signed-off-by: Colin Ian King --- security/integrity/ima/ima_template.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c index 24775f3..004723c 100644 --- a/security/integrity/ima/ima_template.c +++ b/security/integrity/ima/ima_template.c @@ -395,7 +395,7 @@ int ima_restore_measurement_list(loff_t size, void *buf) hdr_v1->template_name_len = le32_to_cpu(hdr_v1->template_name_len); - if ((hdr_v1->template_name_len > MAX_TEMPLATE_NAME_LEN) || + if ((hdr_v1->template_name_len >= MAX_TEMPLATE_NAME_LEN) || ((bufp + hdr_v1->template_name_len) > bufendp)) { pr_err("attempting to restore a template name \ that is too long\n"); -- 2.9.3