From patchwork Fri Jan 8 05:32:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lokesh Gidra X-Patchwork-Id: 12005797 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=-26.6 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,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 12942C43333 for ; Fri, 8 Jan 2021 05:34:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D56D9233FB for ; Fri, 8 Jan 2021 05:34:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727953AbhAHFeF (ORCPT ); Fri, 8 Jan 2021 00:34:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56548 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727900AbhAHFeE (ORCPT ); Fri, 8 Jan 2021 00:34:04 -0500 Received: from mail-qv1-xf49.google.com (mail-qv1-xf49.google.com [IPv6:2607:f8b0:4864:20::f49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 09269C0612FC for ; Thu, 7 Jan 2021 21:33:04 -0800 (PST) Received: by mail-qv1-xf49.google.com with SMTP id t17so7431849qvv.17 for ; Thu, 07 Jan 2021 21:33:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=4KH1yzDb8snTvZnWPZ6fdUzRnCevlmVN32CkdvE/ol0=; b=OooG9vnAq2ysyycbcX08KiXI5S0HJbbgcA9Z9Oe2Ez2suyGyVQeZttS0HO9/+UCX/V PjCh7xJBw+TdGVoIZS/5qgRIm1qmo97LfRBqabAIBI1eElk2H8vl7Iq2/mJF/OvpbxZv S2DHBKn5hwyOvzL+cFt33QWpegpu0/4RIQXbtBugszlnBsVDw6iZPwE3EwdLtZnuE4jb iXk8Ya9/XnKUJPuZ9NKZuMg0V/wwMZIaYhIfU5f7QeWo9mpEC+S7/MxUfwosRALlsS7z VyixOvAGTgm5BqbxTBEz6lPVVpEjwtub+alQLQhkEdpqshrKURlxVPoAjGWDT9RlyPXj UuXg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=4KH1yzDb8snTvZnWPZ6fdUzRnCevlmVN32CkdvE/ol0=; b=IhSFc9thgBj+s7WQ46e9+AvFj4Lmy0MFQ/XnlCA3oea2FH812KoQ1jXyCv/cT9Ih1L Kx/Ie0/aw6TM62J3IKHf0zZEesdO6YcJOCkJ46EhHrVmaNlmR4hW6+AA8HxXpLw1mxbM mki4W4g1u0Wovrl4Fw+ANjYc2WyNcErTJizbQra20a5pZom7zWfFb8a5pJ+4gqgOeSgJ P1cfxzxx3haglThw/yo9msX08WVUEwU2MKNfLiYFn+D3U+tHn4uefBFA/dUxcrSR9y8J ncSxP/SPXlp1VoICG5k4Ydl/q4QfWPzaaJwigrcXtJ8HUIFEgEWtUq+D65c5BK+Wrzig /Wkw== X-Gm-Message-State: AOAM530XTuSZnLUkYL2WoWT4XCfhPKBGIuI3pVQAdkoDj5cUb6rMTnYr eyhiXnz5XdbGO0g4c2H/zDHpHnjZgq/vBJxfCQ== X-Google-Smtp-Source: ABdhPJxe5Xp0qHN/Ia6xoJMR+ESmUkHT1cbbplCD/GFyfD/HcPhZbdQJMkeXAwcx0bM8pckO4liRgJmF06RFMLCLzQ== Sender: "lokeshgidra via sendgmr" X-Received: from lg.mtv.corp.google.com ([2620:15c:211:202:f693:9fff:fef4:29dd]) (user=lokeshgidra job=sendgmr) by 2002:a0c:bd2b:: with SMTP id m43mr2274696qvg.32.1610083983055; Thu, 07 Jan 2021 21:33:03 -0800 (PST) Date: Thu, 7 Jan 2021 21:32:56 -0800 In-Reply-To: <20210108053259.726613-1-lokeshgidra@google.com> Message-Id: <20210108053259.726613-2-lokeshgidra@google.com> Mime-Version: 1.0 References: <20210108053259.726613-1-lokeshgidra@google.com> X-Mailer: git-send-email 2.30.0.284.gd98b1dd5eaa7-goog Subject: [PATCH v14 1/4] security: add inode_init_security_anon() LSM hook From: Lokesh Gidra To: Andrea Arcangeli , Alexander Viro , James Morris , Stephen Smalley , Casey Schaufler , Eric Biggers , Paul Moore Cc: "Serge E. Hallyn" , Eric Paris , Lokesh Gidra , Daniel Colascione , Kees Cook , "Eric W. Biederman" , KP Singh , David Howells , Anders Roxell , Sami Tolvanen , Matthew Garrett , Randy Dunlap , "Joel Fernandes (Google)" , YueHaibing , Christian Brauner , Alexei Starovoitov , Adrian Reber , Aleksa Sarai , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org, kaleshsingh@google.com, calin@google.com, surenb@google.com, jeffv@google.com, kernel-team@android.com, linux-mm@kvack.org, Andrew Morton , hch@infradead.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org This change adds a new LSM hook, inode_init_security_anon(), that will be used while creating secure anonymous inodes. The hook allows/denies its creation and assigns a security context to the inode. The new hook accepts an optional context_inode parameter that callers can use to provide additional contextual information to security modules for granting/denying permission to create an anon-inode of the same type. This context_inode's security_context can also be used to initialize the newly created anon-inode's security_context. Signed-off-by: Lokesh Gidra Reviewed-by: Eric Biggers --- include/linux/lsm_hook_defs.h | 2 ++ include/linux/lsm_hooks.h | 9 +++++++++ include/linux/security.h | 10 ++++++++++ security/security.c | 8 ++++++++ 4 files changed, 29 insertions(+) diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 7aaa753b8608..dfd261dcbcb0 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -113,6 +113,8 @@ LSM_HOOK(void, LSM_RET_VOID, inode_free_security, struct inode *inode) LSM_HOOK(int, 0, inode_init_security, struct inode *inode, struct inode *dir, const struct qstr *qstr, const char **name, void **value, size_t *len) +LSM_HOOK(int, 0, inode_init_security_anon, struct inode *inode, + const struct qstr *name, const struct inode *context_inode) LSM_HOOK(int, 0, inode_create, struct inode *dir, struct dentry *dentry, umode_t mode) LSM_HOOK(int, 0, inode_link, struct dentry *old_dentry, struct inode *dir, diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index a19adef1f088..bdfc8a76a4f7 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -233,6 +233,15 @@ * Returns 0 if @name and @value have been successfully set, * -EOPNOTSUPP if no security attribute is needed, or * -ENOMEM on memory allocation failure. + * @inode_init_security_anon: + * Set up the incore security field for the new anonymous inode + * and return whether the inode creation is permitted by the security + * module or not. + * @inode contains the inode structure + * @name name of the anonymous inode class + * @context_inode optional related inode + * Returns 0 on success, -EACCES if the security module denies the + * creation of this inode, or another -errno upon other errors. * @inode_create: * Check permission to create a regular file. * @dir contains inode structure of the parent of the new file. diff --git a/include/linux/security.h b/include/linux/security.h index c35ea0ffccd9..b0d14f04b16d 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -324,6 +324,9 @@ void security_inode_free(struct inode *inode); int security_inode_init_security(struct inode *inode, struct inode *dir, const struct qstr *qstr, initxattrs initxattrs, void *fs_data); +int security_inode_init_security_anon(struct inode *inode, + const struct qstr *name, + const struct inode *context_inode); int security_old_inode_init_security(struct inode *inode, struct inode *dir, const struct qstr *qstr, const char **name, void **value, size_t *len); @@ -738,6 +741,13 @@ static inline int security_inode_init_security(struct inode *inode, return 0; } +static inline int security_inode_init_security_anon(struct inode *inode, + const struct qstr *name, + const struct inode *context_inode) +{ + return 0; +} + static inline int security_old_inode_init_security(struct inode *inode, struct inode *dir, const struct qstr *qstr, diff --git a/security/security.c b/security/security.c index 7b09cfbae94f..401663b5b70e 100644 --- a/security/security.c +++ b/security/security.c @@ -1059,6 +1059,14 @@ int security_inode_init_security(struct inode *inode, struct inode *dir, } EXPORT_SYMBOL(security_inode_init_security); +int security_inode_init_security_anon(struct inode *inode, + const struct qstr *name, + const struct inode *context_inode) +{ + return call_int_hook(inode_init_security_anon, 0, inode, name, + context_inode); +} + int security_old_inode_init_security(struct inode *inode, struct inode *dir, const struct qstr *qstr, const char **name, void **value, size_t *len)