From patchwork Tue Jun 23 00:32:26 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tyler Hicks X-Patchwork-Id: 11619465 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 45CE06C1 for ; Tue, 23 Jun 2020 00:34:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 275FB20720 for ; Tue, 23 Jun 2020 00:34:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="nzgJGY7U" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731455AbgFWAeO (ORCPT ); Mon, 22 Jun 2020 20:34:14 -0400 Received: from linux.microsoft.com ([13.77.154.182]:47402 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731810AbgFWAeM (ORCPT ); Mon, 22 Jun 2020 20:34:12 -0400 Received: from sequoia.work.tihix.com (162-237-133-238.lightspeed.rcsntx.sbcglobal.net [162.237.133.238]) by linux.microsoft.com (Postfix) with ESMTPSA id 2781D20B4781; Mon, 22 Jun 2020 17:34:11 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 2781D20B4781 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1592872451; bh=HChxERWUuKwjZ6R4JVcz82wzO1+OLldut5JYoeoGT9c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nzgJGY7Uf9mbUguoerps5DSxzKd5vMC5C9cSL7iFFECcIwyYO4d6+qI3xOHZmjRUP KZlR4//r3cfGsh+TM1NQ06cAwc1otxTTHB79mKO1Bvcn6VKMSavjFb3z6w89l7RcRF qNL8WGZPbdjJjLtgTblm5ZPzV6n4U7daB0s1PLQQ= From: Tyler Hicks To: Mimi Zohar , Dmitry Kasatkin Cc: James Morris , "Serge E . Hallyn" , Lakshmi Ramasubramanian , Prakhar Srivastava , linux-kernel@vger.kernel.org, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH 02/12] ima: Create a function to free a rule entry Date: Mon, 22 Jun 2020 19:32:26 -0500 Message-Id: <20200623003236.830149-3-tyhicks@linux.microsoft.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200623003236.830149-1-tyhicks@linux.microsoft.com> References: <20200623003236.830149-1-tyhicks@linux.microsoft.com> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: There are several possible pieces of allocated memory in a rule entry. Create a function that can free all allocated memory for a given rule entry. This patch introduces no functional changes but sets the groundwork for some memory leak fixes. Signed-off-by: Tyler Hicks --- security/integrity/ima/ima_policy.c | 33 +++++++++++++++++++++++++++-- 1 file changed, 31 insertions(+), 2 deletions(-) diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 236a731492d1..1320333201c6 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -261,6 +261,27 @@ static void ima_lsm_free_rule(struct ima_rule_entry *entry) security_filter_rule_free(entry->lsm[i].rule); kfree(entry->lsm[i].args_p); } +} + +static void ima_free_rule(struct ima_rule_entry *entry) +{ + if (!entry) + return; + + /* + * entry->template->fields may be allocated in ima_parse_rule() but that + * reference is owned by the corresponding ima_template_desc element in + * the defined_templates list and cannot be freed here + */ + + /* + * When freeing newly added ima_rule_entry members, consider if you + * need to disown any references after the shallow copy in + * ima_lsm_copy_rule() + */ + kfree(entry->fsname); + kfree(entry->keyrings); + ima_lsm_free_rule(entry); kfree(entry); } @@ -298,10 +319,18 @@ static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry) pr_warn("rule for LSM \'%s\' is undefined\n", (char *)entry->lsm[i].args_p); } + + /* Disown all references that were shallow copied */ + entry->fsname = NULL; + entry->keyrings = NULL; + entry->template = NULL; return nentry; out_err: - ima_lsm_free_rule(nentry); + nentry->fsname = NULL; + nentry->keyrings = NULL; + nentry->template = NULL; + ima_free_rule(nentry); return NULL; } @@ -315,7 +344,7 @@ static int ima_lsm_update_rule(struct ima_rule_entry *entry) list_replace_rcu(&entry->list, &nentry->list); synchronize_rcu(); - ima_lsm_free_rule(entry); + ima_free_rule(entry); return 0; }