From patchwork Wed Jun 5 08:36:06 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Janne Karhunen X-Patchwork-Id: 10976473 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0476E76 for ; Wed, 5 Jun 2019 08:36:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EBC4228770 for ; Wed, 5 Jun 2019 08:36:54 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E0706288C7; Wed, 5 Jun 2019 08:36:54 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4E34228770 for ; Wed, 5 Jun 2019 08:36:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726695AbfFEIgy (ORCPT ); Wed, 5 Jun 2019 04:36:54 -0400 Received: from mail-lf1-f65.google.com ([209.85.167.65]:35051 "EHLO mail-lf1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726674AbfFEIgx (ORCPT ); Wed, 5 Jun 2019 04:36:53 -0400 Received: by mail-lf1-f65.google.com with SMTP id a25so18472176lfg.2; Wed, 05 Jun 2019 01:36:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=yAY2x4M2ZvsX6SGgora+JblNOtjrwOO5ndy8yz8Qmbo=; b=btfdArMixbJhY0rY55lpebP2t5pQVRlneqmBJA+qulOEK2S9fIZLAAqmt+Ln/5a5/R f1lTFe8gvrImCn/mSemvyL4DnlBREwrZ/dn71rb8gzTO3Mu/dx8FIvN4p7oF9nm5CT39 hLLp688CR7tZaxE1GqYCE+4WpyiqVgH2KPaSiB3TiWcwqf4x7We95z0EuGxvLCxzsP/J 0KkNmhdqr4XK6EU8m9pt5Es2UyQlVuugA6XbATZZwJ5c0XfdIUJZcZ9JPO9hx/u6Eb9X WHHr6OPfLvbe/R/cDmOQ46EI2zmeHM/M/BCqcVj/iIYis0GqFX7zvjiP4LK3AaMWeCYi 2H7g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=yAY2x4M2ZvsX6SGgora+JblNOtjrwOO5ndy8yz8Qmbo=; b=tmcHM01X6zo+Ld/PfroUrkbePdKh9LNcrso/xvNV/z4jcve3BYXgAJo5+tLJnCh6w+ NxnvWaO+6NJYAA3tQnXsrdmqRM4ZHGBiormj1rKz1H3O08hV2oAUnxTUTN20VTsYwsEq VrxWnsQ7SBRNTKzVjQr4ogKBaVE0R5bt2e+5FK6oZexQ+2AhH38G4TR54ETnYjQtW6nX lgYg65fJUy8QByX6rVK/ZV8u0HBTmAUObRyRjEwobw37hXfzTFaFkenQwLrlDgYDv2eM i7cAhRE1+DY5P23CFzPFRyCk+x30g6S2XaRmGRSYvGnMT0mVD62VjGpe46YdhH8QGT1y sDRQ== X-Gm-Message-State: APjAAAWqGb02gPC0p/0n4/x/sAdXbpsD5Sp/Vk5wk0JmCwu0onEzRkaT IPpDo4tqfJoQXSV2c0qVWVFg8iHfkro= X-Google-Smtp-Source: APXvYqxRG47fyEfSM1m6YuO3gyrNyVx9PH54Z9AZVprfYBL7Q0cyFuPJZb7lRV1Zl0i+xjSeo5E6Ww== X-Received: by 2002:a19:521a:: with SMTP id m26mr4683740lfb.134.1559723811337; Wed, 05 Jun 2019 01:36:51 -0700 (PDT) Received: from localhost.localdomain (mobile-user-c1d2e6-229.dhcp.inet.fi. [193.210.230.229]) by smtp.gmail.com with ESMTPSA id t21sm1392637ljg.60.2019.06.05.01.36.50 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 05 Jun 2019 01:36:50 -0700 (PDT) From: Janne Karhunen To: sds@tycho.nsa.gov, zohar@linux.ibm.com, paul@paul-moore.com Cc: linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, Janne Karhunen Subject: [PATCH 2/2] ima: use the lsm policy update notifier Date: Wed, 5 Jun 2019 11:36:06 +0300 Message-Id: <20190605083606.4209-2-janne.karhunen@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190605083606.4209-1-janne.karhunen@gmail.com> References: <20190605083606.4209-1-janne.karhunen@gmail.com> Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Don't do lazy policy updates while running the rule matching, run the updates as they happen. Depends on commit 2d1d5cee66d1 ("LSM: switch to blocking policy update notifiers") Signed-off-by: Janne Karhunen --- security/integrity/ima/ima.h | 2 + security/integrity/ima/ima_main.c | 8 ++ security/integrity/ima/ima_policy.c | 124 +++++++++++++++++++++++----- 3 files changed, 114 insertions(+), 20 deletions(-) diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index d213e835c498..2203451862d4 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -154,6 +154,8 @@ unsigned long ima_get_binary_runtime_size(void); int ima_init_template(void); void ima_init_template_list(void); int __init ima_init_digests(void); +int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event, + void *lsm_data); /* * used to protect h_table and sha_table diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index f16353b5097e..9e3ea8a3f2db 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -43,6 +43,10 @@ int ima_appraise; int ima_hash_algo = HASH_ALGO_SHA1; static int hash_setup_done; +static struct notifier_block ima_lsm_policy_notifier = { + .notifier_call = ima_lsm_policy_change, +}; + static int __init hash_setup(char *str) { struct ima_template_desc *template_desc = ima_template_desc_current(); @@ -621,6 +625,10 @@ static int __init init_ima(void) error = ima_init(); } + error = register_blocking_lsm_notifier(&ima_lsm_policy_notifier); + if (error) + pr_warn("Couldn't register LSM notifier, error %d\n", error); + if (!error) ima_update_policy_flag(); diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 1cc822a59054..7129dc4cd396 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -249,31 +249,121 @@ static int __init default_appraise_policy_setup(char *str) } __setup("ima_appraise_tcb", default_appraise_policy_setup); +static void ima_lsm_free_rule(struct ima_rule_entry *entry) +{ + int i; + + for (i = 0; i < MAX_LSM_RULES; i++) { + kfree(entry->lsm[i].rule); + kfree(entry->lsm[i].args_p); + } + kfree(entry->fsname); + kfree(entry); +} + + +static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry) +{ + struct ima_rule_entry *nentry; + int i, result; + + nentry = kmalloc(sizeof(*nentry), GFP_KERNEL); + if (!nentry) + return NULL; + + memcpy(nentry, entry, sizeof(*nentry)); + nentry->fsname = NULL; + for (i = 0; i < MAX_LSM_RULES; i++) { + nentry->lsm[i].rule = NULL; + nentry->lsm[i].args_p = NULL; + } + + if (entry->fsname) { + nentry->fsname = kstrdup(entry->fsname, GFP_KERNEL); + if (!nentry->fsname) + goto out_err; + } + for (i = 0; i < MAX_LSM_RULES; i++) { + if (!entry->lsm[i].rule) + continue; + + nentry->lsm[i].type = entry->lsm[i].type; + nentry->lsm[i].args_p = kstrdup(entry->lsm[i].args_p, + GFP_KERNEL); + if (!nentry->lsm[i].args_p) + goto out_err; + + result = security_filter_rule_init(nentry->lsm[i].type, + Audit_equal, + nentry->lsm[i].args_p, + &nentry->lsm[i].rule); + if (result == -EINVAL) + pr_warn("ima: rule for LSM \'%d\' is invalid\n", + entry->lsm[i].type); + + } + return nentry; + +out_err: + ima_lsm_free_rule(nentry); + return NULL; +} + +static int ima_lsm_update_rule(struct ima_rule_entry *entry) +{ + struct ima_rule_entry *nentry; + + nentry = ima_lsm_copy_rule(entry); + if (!nentry) + return -ENOMEM; + + list_replace_rcu(&entry->list, &nentry->list); + synchronize_rcu(); + ima_lsm_free_rule(entry); + + return 0; +} + /* * The LSM policy can be reloaded, leaving the IMA LSM based rules referring * to the old, stale LSM policy. Update the IMA LSM based rules to reflect - * the reloaded LSM policy. We assume the rules still exist; and BUG_ON() if - * they don't. + * the reloaded LSM policy. */ static void ima_lsm_update_rules(void) { - struct ima_rule_entry *entry; - int result; - int i; + struct ima_rule_entry *entry, *e; + int i, result, needs_update; - list_for_each_entry(entry, &ima_policy_rules, list) { + list_for_each_entry_safe(entry, e, &ima_policy_rules, list) { + needs_update = 0; for (i = 0; i < MAX_LSM_RULES; i++) { - if (!entry->lsm[i].rule) - continue; - result = security_filter_rule_init(entry->lsm[i].type, - Audit_equal, - entry->lsm[i].args_p, - &entry->lsm[i].rule); - BUG_ON(!entry->lsm[i].rule); + if (entry->lsm[i].rule) { + needs_update = 1; + break; + } + } + if (!needs_update) + continue; + + result = ima_lsm_update_rule(entry); + if (result) { + pr_err("ima: lsm rule update error %d\n", + result); + return; } } } +int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event, + void *lsm_data) +{ + if (event != LSM_POLICY_CHANGE) + return NOTIFY_DONE; + + ima_lsm_update_rules(); + return NOTIFY_OK; +} + /** * ima_match_rules - determine whether an inode matches the measure rule. * @rule: a pointer to a rule @@ -327,11 +417,10 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode, for (i = 0; i < MAX_LSM_RULES; i++) { int rc = 0; u32 osid; - int retried = 0; if (!rule->lsm[i].rule) continue; -retry: + switch (i) { case LSM_OBJ_USER: case LSM_OBJ_ROLE: @@ -352,11 +441,6 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode, default: break; } - if ((rc < 0) && (!retried)) { - retried = 1; - ima_lsm_update_rules(); - goto retry; - } if (!rc) return false; }