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=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 C81C7C433E0 for ; Wed, 29 Jul 2020 17:59:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E5392075D for ; Wed, 29 Jul 2020 17:59:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="ZZB5JK//" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727975AbgG2R7J (ORCPT ); Wed, 29 Jul 2020 13:59:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35696 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727928AbgG2R7H (ORCPT ); Wed, 29 Jul 2020 13:59:07 -0400 Received: from mail-pf1-x441.google.com (mail-pf1-x441.google.com [IPv6:2607:f8b0:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C6F58C0619E0 for ; Wed, 29 Jul 2020 10:59:06 -0700 (PDT) Received: by mail-pf1-x441.google.com with SMTP id w126so13154586pfw.8 for ; Wed, 29 Jul 2020 10:59:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=d+cxh7Adx01Lz+PZ0BqdBZD0tuhqHe+fIcb3T8VVshI=; b=ZZB5JK//OYdCgnZb/fU8QzTjp427UrGSGiw79T8stn6rtJuQa9EpnWg2nqhPKWluxW W6G5fG+ztYpEQLf1lCq0MlQ9zNk4q/Y5m3gxLuSfvTXmmiKW5Rv4D1MaN0sW3Ja7Djt+ EOHWd0VX606jZjeyOdUtx/H0g56YaQIalcg6A= 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:mime-version:content-transfer-encoding; bh=d+cxh7Adx01Lz+PZ0BqdBZD0tuhqHe+fIcb3T8VVshI=; b=ljiGHSuCYZ6rJA/ujpqXzaPRZxjTvr8eFNMZlldp4gSc2H6xMYOLR7lrltm2eJfdQN +WgvoVPk2z9RaHFnNa5n2PVrC28rHSXEnMbgIxb5K1PhqnU22JAavqnHOiKBxYHZjaKH L0HMaSXNQClrb4uIq+MA7sJjNxRIZe8xar4h5TyYPmbtAy1CXh6ItFHQmuDorMDEphI3 7lmg8KvwvqbJXb5fl5Y21rxMtzhE9cuE4aS6imOaHHQq56i7hY8ATH5Z096yXJ1c9Pc4 2llUMEFST7HHLDx8fDembcip3NrO4mxbMVdZVenfxsYpi7c9x4GAzW9CFC+OoTbeKlNQ 1QjA== X-Gm-Message-State: AOAM5303znJ6SBUct0wUwGvt45jc34ttb1S6v8NyZ08YyII9DPy8rIbk mqQ0qVjgBR074CWMFHg4DZ4GQA== X-Google-Smtp-Source: ABdhPJzwV8yZ+vHoQE7rb6HkYEvIykxXV/ucl+4R0uhyvLJBDEppIOQPIpaDe7F8tvEjOO8IV+mKow== X-Received: by 2002:a63:ce41:: with SMTP id r1mr31178572pgi.203.1596045546377; Wed, 29 Jul 2020 10:59:06 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id y10sm3081590pff.187.2020.07.29.10.58.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 29 Jul 2020 10:59:04 -0700 (PDT) From: Kees Cook To: Greg Kroah-Hartman Cc: Kees Cook , Scott Branden , Mimi Zohar , Luis Chamberlain , Takashi Iwai , Jessica Yu , SeongJae Park , KP Singh , linux-efi@vger.kernel.org, linux-security-module@vger.kernel.org, linux-integrity@vger.kernel.org, selinux@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 13/17] IMA: Add support for file reads without contents Date: Wed, 29 Jul 2020 10:58:41 -0700 Message-Id: <20200729175845.1745471-14-keescook@chromium.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200729175845.1745471-1-keescook@chromium.org> References: <20200729175845.1745471-1-keescook@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: From: Scott Branden When the kernel_read_file LSM hook is called with contents=false, IMA can appraise the file directly, without requiring a filled buffer. When such a buffer is available, though, IMA can continue to use it instead of forcing a double read here. Signed-off-by: Scott Branden Link: https://lore.kernel.org/lkml/20200706232309.12010-10-scott.branden@broadcom.com/ Reviewed-by: Mimi Zohar Signed-off-by: Kees Cook --- security/integrity/ima/ima_main.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index dc4f90660aa6..de57fce5bced 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -613,11 +613,8 @@ void ima_post_path_mknod(struct dentry *dentry) int ima_read_file(struct file *file, enum kernel_read_file_id read_id, bool contents) { - /* Reject all partial reads during appraisal. */ - if (!contents) { - if (ima_appraise & IMA_APPRAISE_ENFORCE) - return -EACCES; - } + enum ima_hooks func; + u32 secid; /* * Do devices using pre-allocated memory run the risk of the @@ -626,7 +623,20 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id, * buffers? It may be desirable to include the buffer address * in this API and walk all the dma_map_single() mappings to check. */ - return 0; + + /* + * There will be a call made to ima_post_read_file() with + * a filled buffer, so we don't need to perform an extra + * read early here. + */ + if (contents) + return 0; + + /* Read entire file for all partial reads. */ + func = read_idmap[read_id] ?: FILE_CHECK; + security_task_getsecid(current, &secid); + return process_measurement(file, current_cred(), secid, NULL, + 0, MAY_READ, func); } const int read_idmap[READING_MAX_ID] = { -- 2.25.1