From patchwork Fri Sep 9 01:15:15 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Guozihua (Scott)" X-Patchwork-Id: 12970892 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 22A4BECAAD5 for ; Fri, 9 Sep 2022 01:19:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229882AbiIIBTE (ORCPT ); Thu, 8 Sep 2022 21:19:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36284 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229610AbiIIBTD (ORCPT ); Thu, 8 Sep 2022 21:19:03 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DE5911098FD; Thu, 8 Sep 2022 18:19:01 -0700 (PDT) Received: from dggpemm500024.china.huawei.com (unknown [172.30.72.55]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4MNyj66Nf8zmVJm; Fri, 9 Sep 2022 09:15:22 +0800 (CST) Received: from huawei.com (10.67.175.31) by dggpemm500024.china.huawei.com (7.185.36.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 9 Sep 2022 09:19:00 +0800 From: GUO Zihua To: , , , , CC: , Subject: [PATCH v4 1/2] ima: Simplify ima_lsm_copy_rule Date: Fri, 9 Sep 2022 09:15:15 +0800 Message-ID: <20220909011516.55957-2-guozihua@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220909011516.55957-1-guozihua@huawei.com> References: <20220909011516.55957-1-guozihua@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.67.175.31] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpemm500024.china.huawei.com (7.185.36.203) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org Currently ima_lsm_copy_rule() set the arg_p field of the source rule to NULL, so that the source rule could be freed afterward. It does not make sense for this behavior to be inside a "copy" function. So move it outside and let the caller handle this field. As of now, the only user of ima_lsm_copy_rule() is ima_lsm_update_rule(). In ima_lsm_update_rule(), we would like to free only the lsm.rule in the old rule entry, and leave arg_p untouch. In this case, it's better to use ima_filter_rule_free() directly and not introduce another for loop to set arg_p to NULL. Signed-off-by: GUO Zihua --- security/integrity/ima/ima_policy.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index a8802b8da946..8040215c0252 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -398,12 +398,6 @@ static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry) nentry->lsm[i].type = entry->lsm[i].type; nentry->lsm[i].args_p = entry->lsm[i].args_p; - /* - * Remove the reference from entry so that the associated - * memory will not be freed during a later call to - * ima_lsm_free_rule(entry). - */ - entry->lsm[i].args_p = NULL; ima_filter_rule_init(nentry->lsm[i].type, Audit_equal, nentry->lsm[i].args_p, @@ -417,6 +411,7 @@ static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry) static int ima_lsm_update_rule(struct ima_rule_entry *entry) { + int i; struct ima_rule_entry *nentry; nentry = ima_lsm_copy_rule(entry); @@ -431,7 +426,8 @@ static int ima_lsm_update_rule(struct ima_rule_entry *entry) * references and the entry itself. All other memory references will now * be owned by nentry. */ - ima_lsm_free_rule(entry); + for (i = 0; i < MAX_LSM_RULES; i++) + ima_filter_rule_free(entry->lsm[i].rule); kfree(entry); return 0; From patchwork Fri Sep 9 01:15:16 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Guozihua (Scott)" X-Patchwork-Id: 12970894 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B057C6FA8B for ; Fri, 9 Sep 2022 01:19:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229686AbiIIBTF (ORCPT ); Thu, 8 Sep 2022 21:19:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36290 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229819AbiIIBTE (ORCPT ); Thu, 8 Sep 2022 21:19:04 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 551D5109D15; Thu, 8 Sep 2022 18:19:02 -0700 (PDT) Received: from dggpemm500024.china.huawei.com (unknown [172.30.72.53]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4MNyl370HfzHnVm; Fri, 9 Sep 2022 09:17:03 +0800 (CST) Received: from huawei.com (10.67.175.31) by dggpemm500024.china.huawei.com (7.185.36.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 9 Sep 2022 09:19:00 +0800 From: GUO Zihua To: , , , , CC: , Subject: [PATCH v4 2/2] ima: Handle -ESTALE returned by ima_filter_rule_match() Date: Fri, 9 Sep 2022 09:15:16 +0800 Message-ID: <20220909011516.55957-3-guozihua@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220909011516.55957-1-guozihua@huawei.com> References: <20220909011516.55957-1-guozihua@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.67.175.31] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpemm500024.china.huawei.com (7.185.36.203) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org IMA relies on the blocking LSM policy notifier callback to update the LSM based IMA policy rules. When SELinux update its policies, IMA would be notified and starts updating all its lsm rules one-by-one. During this time, -ESTALE would be returned by ima_filter_rule_match() if it is called with a LSM rule that has not yet been updated. In ima_match_rules(), -ESTALE is not handled, and the LSM rule is considered a match, causing extra files to be measured by IMA. Fix it by re-initializing a temporary rule if -ESTALE is returned by ima_filter_rule_match(). The origin rule in the rule list would be updated by the LSM policy notifier callback. Fixes: b16942455193 ("ima: use the lsm policy update notifier") Signed-off-by: GUO Zihua --- security/integrity/ima/ima_policy.c | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-) diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 8040215c0252..cb672df9b888 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -545,6 +545,8 @@ static bool ima_match_rules(struct ima_rule_entry *rule, const char *func_data) { int i; + bool result = false; + bool rule_reinitialized = false; if ((rule->flags & IMA_FUNC) && (rule->func != func && func != POST_SETATTR)) @@ -612,6 +614,8 @@ static bool ima_match_rules(struct ima_rule_entry *rule, else return false; } + +retry: switch (i) { case LSM_OBJ_USER: case LSM_OBJ_ROLE: @@ -631,10 +635,28 @@ static bool ima_match_rules(struct ima_rule_entry *rule, default: break; } - if (!rc) - return false; + + if (rc == -ESTALE) { + rule = ima_lsm_copy_rule(rule); + if (rule) { + rule_reinitialized = true; + goto retry; + } + } + if (!rc) { + result = false; + goto out; + } } - return true; + result = true; + +out: + if (rule_reinitialized) { + for (i = 0; i < MAX_LSM_RULES; i++) + ima_filter_rule_free(rule->lsm[i].rule); + kfree(rule); + } + return result; } /*