From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-24.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AB818C07E9C for ; Tue, 6 Jul 2021 19:19:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8CAD961C7A for ; Tue, 6 Jul 2021 19:19:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231866AbhGFTVt (ORCPT ); Tue, 6 Jul 2021 15:21:49 -0400 Received: from linux.microsoft.com ([13.77.154.182]:41376 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231774AbhGFTVt (ORCPT ); Tue, 6 Jul 2021 15:21:49 -0400 Received: from [10.137.112.111] (unknown [131.107.147.111]) by linux.microsoft.com (Postfix) with ESMTPSA id 4E1F320B7188; Tue, 6 Jul 2021 12:19:10 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 4E1F320B7188 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1625599150; bh=HAyiPMPlknf585eyjiByUkZYMcEfesGAqJ5IRtDhZNY=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=cw2ZMpdXbJc2YaqalFiZFCL2zmBUDnNh/RiSOFP2Wggm2eE5TVzXqFerw1CYvhy+/ eM0D7iqhnJp4l+wiiEIS643DB+s02Ry+iUnZuuvIAZWpprtuo1IQsAaTcaUnoEgaiZ 0zAPn4Sm907XkbmpCgwGjJNxKOgAohrkVfrMmvgs= Subject: Re: [PATCH v3 2/3] ima: Return int in the functions to measure a buffer To: Roberto Sassu , zohar@linux.ibm.com, paul@paul-moore.com Cc: stephen.smalley.work@gmail.com, prsriva02@gmail.com, tusharsu@linux.microsoft.com, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, selinux@vger.kernel.org References: <20210705090922.3321178-1-roberto.sassu@huawei.com> <20210705090922.3321178-3-roberto.sassu@huawei.com> From: Lakshmi Ramasubramanian Message-ID: <5bc9d707-b193-6111-fea6-50c70e6f2245@linux.microsoft.com> Date: Tue, 6 Jul 2021 12:21:04 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210705090922.3321178-3-roberto.sassu@huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: selinux@vger.kernel.org On 7/5/2021 2:09 AM, Roberto Sassu wrote: > ima_measure_critical_data() and process_buffer_measurement() currently > don't return a result. A caller wouldn't be able to know whether those > functions were executed successfully. > > This patch modifies the return type from void to int, and returns 0 if the > buffer has been successfully measured, a negative value otherwise. > > Also, this patch does not modify the behavior of existing callers by > processing the returned value. For those, the return value is ignored. > > Signed-off-by: Roberto Sassu > --- > include/linux/ima.h | 15 +++++++----- > security/integrity/ima/ima.h | 10 ++++---- > security/integrity/ima/ima_main.c | 40 ++++++++++++++++++------------- > 3 files changed, 37 insertions(+), 28 deletions(-) Reviewed-by: Lakshmi Ramasubramanian -lakshmi > > diff --git a/include/linux/ima.h b/include/linux/ima.h > index 81e830d01ced..60492263aa64 100644 > --- a/include/linux/ima.h > +++ b/include/linux/ima.h > @@ -35,10 +35,10 @@ extern void ima_post_path_mknod(struct user_namespace *mnt_userns, > extern int ima_file_hash(struct file *file, char *buf, size_t buf_size); > extern int ima_inode_hash(struct inode *inode, char *buf, size_t buf_size); > extern void ima_kexec_cmdline(int kernel_fd, const void *buf, int size); > -extern void ima_measure_critical_data(const char *event_label, > - const char *event_name, > - const void *buf, size_t buf_len, > - bool hash); > +extern int ima_measure_critical_data(const char *event_label, > + const char *event_name, > + const void *buf, size_t buf_len, > + bool hash); > > #ifdef CONFIG_IMA_APPRAISE_BOOTPARAM > extern void ima_appraise_parse_cmdline(void); > @@ -144,10 +144,13 @@ static inline int ima_inode_hash(struct inode *inode, char *buf, size_t buf_size > > static inline void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) {} > > -static inline void ima_measure_critical_data(const char *event_label, > +static inline int ima_measure_critical_data(const char *event_label, > const char *event_name, > const void *buf, size_t buf_len, > - bool hash) {} > + bool hash) > +{ > + return -ENOENT; > +} > > #endif /* CONFIG_IMA */ > > diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h > index f0e448ed1f9f..03db221324c3 100644 > --- a/security/integrity/ima/ima.h > +++ b/security/integrity/ima/ima.h > @@ -264,11 +264,11 @@ void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file, > struct evm_ima_xattr_data *xattr_value, > int xattr_len, const struct modsig *modsig, int pcr, > struct ima_template_desc *template_desc); > -void process_buffer_measurement(struct user_namespace *mnt_userns, > - struct inode *inode, const void *buf, int size, > - const char *eventname, enum ima_hooks func, > - int pcr, const char *func_data, > - bool buf_hash); > +int process_buffer_measurement(struct user_namespace *mnt_userns, > + struct inode *inode, const void *buf, int size, > + const char *eventname, enum ima_hooks func, > + int pcr, const char *func_data, > + bool buf_hash); > void ima_audit_measurement(struct integrity_iint_cache *iint, > const unsigned char *filename); > int ima_alloc_init_template(struct ima_event_data *event_data, > diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c > index 8ef1fa357e0c..b512c06d8ee1 100644 > --- a/security/integrity/ima/ima_main.c > +++ b/security/integrity/ima/ima_main.c > @@ -827,7 +827,7 @@ int ima_post_load_data(char *buf, loff_t size, > return 0; > } > > -/* > +/** > * process_buffer_measurement - Measure the buffer or the buffer data hash > * @mnt_userns: user namespace of the mount the inode was found from > * @inode: inode associated with the object being measured (NULL for KEY_CHECK) > @@ -840,12 +840,15 @@ int ima_post_load_data(char *buf, loff_t size, > * @buf_hash: measure buffer data hash > * > * Based on policy, either the buffer data or buffer data hash is measured > + * > + * Return: 0 if the buffer has been successfully measured, a negative value > + * otherwise. > */ > -void process_buffer_measurement(struct user_namespace *mnt_userns, > - struct inode *inode, const void *buf, int size, > - const char *eventname, enum ima_hooks func, > - int pcr, const char *func_data, > - bool buf_hash) > +int process_buffer_measurement(struct user_namespace *mnt_userns, > + struct inode *inode, const void *buf, int size, > + const char *eventname, enum ima_hooks func, > + int pcr, const char *func_data, > + bool buf_hash) > { > int ret = 0; > const char *audit_cause = "ENOMEM"; > @@ -867,7 +870,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns, > u32 secid; > > if (!ima_policy_flag) > - return; > + return -ENOENT; > > template = ima_template_desc_buf(); > if (!template) { > @@ -889,7 +892,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns, > secid, 0, func, &pcr, &template, > func_data); > if (!(action & IMA_MEASURE)) > - return; > + return -ENOENT; > } > > if (!pcr) > @@ -937,7 +940,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns, > func_measure_str(func), > audit_cause, ret, 0, ret); > > - return; > + return ret; > } > > /** > @@ -977,18 +980,21 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) > * and extend the pcr. Examples of critical data could be various data > * structures, policies, and states stored in kernel memory that can > * impact the integrity of the system. > + * > + * Return: 0 if the buffer has been successfully measured, a negative value > + * otherwise. > */ > -void ima_measure_critical_data(const char *event_label, > - const char *event_name, > - const void *buf, size_t buf_len, > - bool hash) > +int ima_measure_critical_data(const char *event_label, > + const char *event_name, > + const void *buf, size_t buf_len, > + bool hash) > { > if (!event_name || !event_label || !buf || !buf_len) > - return; > + return -ENOPARAM; > > - process_buffer_measurement(&init_user_ns, NULL, buf, buf_len, event_name, > - CRITICAL_DATA, 0, event_label, > - hash); > + return process_buffer_measurement(&init_user_ns, NULL, buf, buf_len, > + event_name, CRITICAL_DATA, 0, > + event_label, hash); > } > > static int __init init_ima(void) >