From patchwork Thu Jan 23 01:32:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lakshmi Ramasubramanian X-Patchwork-Id: 11346661 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 1DCF56C1 for ; Thu, 23 Jan 2020 01:32:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EFB9B2467B for ; Thu, 23 Jan 2020 01:32:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="bLJGHieE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726054AbgAWBcN (ORCPT ); Wed, 22 Jan 2020 20:32:13 -0500 Received: from linux.microsoft.com ([13.77.154.182]:55890 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726061AbgAWBcN (ORCPT ); Wed, 22 Jan 2020 20:32:13 -0500 Received: from nramas-ThinkStation-P520.corp.microsoft.com (unknown [131.107.174.108]) by linux.microsoft.com (Postfix) with ESMTPSA id DCF4D20B479A; Wed, 22 Jan 2020 17:32:11 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com DCF4D20B479A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1579743131; bh=/nY96uoMJp5UFNLYIHALLqmSHnbOJjuKRmMufwC67lI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bLJGHieEUym6AsETnkXTh8AQeVB67Um1sblhLxphFyGzN8N417Wue0Rj48P0vu1CH VWBOUTWlFpste+bRKvIwW9q5iPWYK2LUZwUjGTlOjuuv6Px+WcWVnOlwADzr6dVwqm XVhhIn4H9wM0JZhuAJ98YaQSxTFEAfuUwK9kQaNQ= From: Lakshmi Ramasubramanian To: zohar@linux.ibm.com, James.Bottomley@HansenPartnership.com, linux-integrity@vger.kernel.org Cc: sashal@kernel.org, dhowells@redhat.com, linux-kernel@vger.kernel.org, keyrings@vger.kernel.org Subject: [PATCH v9 3/3] IMA: Defined delayed workqueue to free the queued keys Date: Wed, 22 Jan 2020 17:32:06 -0800 Message-Id: <20200123013206.8499-4-nramas@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200123013206.8499-1-nramas@linux.microsoft.com> References: <20200123013206.8499-1-nramas@linux.microsoft.com> Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org Keys queued for measurement should be freed if a custom IMA policy was not loaded. Otherwise, the keys will remain queued forever consuming kernel memory. This patch defines a delayed workqueue to handle the above scenario. The workqueue handler is setup to execute 5 minutes after IMA initialization is completed. If a custom IMA policy is loaded before the workqueue handler is scheduled to execute, the workqueue task is cancelled and any queued keys are processed for measurement. But if a custom policy was not loaded then the queued keys are just freed when the delayed workqueue handler is run. Signed-off-by: Lakshmi Ramasubramanian Reported-by: kernel test robot # sleeping function called from invalid context Reported-by: kbuild test robot # redefinition of ima_init_key_queue() function. --- security/integrity/ima/ima.h | 2 ++ security/integrity/ima/ima_init.c | 8 ++++- security/integrity/ima/ima_queue_keys.c | 44 ++++++++++++++++++++++--- 3 files changed, 48 insertions(+), 6 deletions(-) diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 905ed2f7f778..64317d95363e 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -215,11 +215,13 @@ struct ima_key_entry { size_t payload_len; char *keyring_name; }; +void ima_init_key_queue(void); bool ima_should_queue_key(void); bool ima_queue_key(struct key *keyring, const void *payload, size_t payload_len); void ima_process_queued_keys(void); #else +static inline void ima_init_key_queue(void) {} static inline bool ima_should_queue_key(void) { return false; } static inline bool ima_queue_key(struct key *keyring, const void *payload, diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c index 5d55ade5f3b9..195cb4079b2b 100644 --- a/security/integrity/ima/ima_init.c +++ b/security/integrity/ima/ima_init.c @@ -131,5 +131,11 @@ int __init ima_init(void) ima_init_policy(); - return ima_fs_init(); + rc = ima_fs_init(); + if (rc != 0) + return rc; + + ima_init_key_queue(); + + return rc; } diff --git a/security/integrity/ima/ima_queue_keys.c b/security/integrity/ima/ima_queue_keys.c index 9b561f2b86db..c87c72299191 100644 --- a/security/integrity/ima/ima_queue_keys.c +++ b/security/integrity/ima/ima_queue_keys.c @@ -10,6 +10,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include #include #include "ima.h" @@ -25,6 +26,36 @@ static bool ima_process_keys; static DEFINE_MUTEX(ima_keys_lock); static LIST_HEAD(ima_keys); +/* + * If custom IMA policy is not loaded then keys queued up + * for measurement should be freed. This worker is used + * for handling this scenario. + */ +static long ima_key_queue_timeout = 300000; /* 5 Minutes */ +static void ima_keys_handler(struct work_struct *work); +static DECLARE_DELAYED_WORK(ima_keys_delayed_work, ima_keys_handler); +static bool timer_expired; + +/* + * This worker function frees keys that may still be + * queued up in case custom IMA policy was not loaded. + */ +static void ima_keys_handler(struct work_struct *work) +{ + timer_expired = true; + ima_process_queued_keys(); +} + +/* + * This function sets up a worker to free queued keys in case + * custom IMA policy was never loaded. + */ +void ima_init_key_queue(void) +{ + schedule_delayed_work(&ima_keys_delayed_work, + msecs_to_jiffies(ima_key_queue_timeout)); +} + static void ima_free_key_entry(struct ima_key_entry *entry) { if (entry) { @@ -119,13 +150,16 @@ void ima_process_queued_keys(void) if (!process) return; + if (!timer_expired) + cancel_delayed_work_sync(&ima_keys_delayed_work); list_for_each_entry_safe(entry, tmp, &ima_keys, list) { - process_buffer_measurement(entry->payload, - entry->payload_len, - entry->keyring_name, - KEY_CHECK, 0, - entry->keyring_name); + if (!timer_expired) + process_buffer_measurement(entry->payload, + entry->payload_len, + entry->keyring_name, + KEY_CHECK, 0, + entry->keyring_name); list_del(&entry->list); ima_free_key_entry(entry); }