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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT 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 E073DC04E53 for ; Wed, 15 May 2019 11:56:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B0EE820843 for ; Wed, 15 May 2019 11:56:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557921418; bh=dAx1Ud770CfA15dP1fOgAyDLUuDk5IXqgHlLykRZ8sU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=m9QqY4CYt6BjVymYxqoyoIAh5yTLheNNPYnggWd7LzsWrruFbPi7UxlG3F9ZnWPeB 0e0ei/ncp9pW3K7aRcsuUtHvWKJUWS2mHiE41AnMF7Fy9Zyb+WSENo+bWVjx2WMp4O a3BXcsO1pLyPzTEwol0p4UDSvSmKJesgiXcNIsic= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728629AbfEOLRb (ORCPT ); Wed, 15 May 2019 07:17:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:54768 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730669AbfEOLRb (ORCPT ); Wed, 15 May 2019 07:17:31 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5DC3E20644; Wed, 15 May 2019 11:17:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557919050; bh=dAx1Ud770CfA15dP1fOgAyDLUuDk5IXqgHlLykRZ8sU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JgjEl1aFbS/s+kiaJVZSWKBI+jWrVVlTi+1sPwQlh7Syg4ykQiOUahoKhR+nw2h+T Di1ZKfZZCsWpUGxftji7hPdyotH9udTSXoXlp7oGLjMWlACXTDyxj2Tl18lpmEXFld BhmNuXh6AuZNs9xD3XMySch1aDuKQZDAXwbass4s= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Goldwyn Rodrigues , Mimi Zohar , Sasha Levin Subject: [PATCH 4.14 046/115] ima: open a new file instance if no read permissions Date: Wed, 15 May 2019 12:55:26 +0200 Message-Id: <20190515090702.901419593@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190515090659.123121100@linuxfoundation.org> References: <20190515090659.123121100@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org [ Upstream commit a408e4a86b36bf98ad15b9ada531cf0e5118ac67 ] Open a new file instance as opposed to changing file->f_mode when the file is not readable. This is done to accomodate overlayfs stacked file operations change. The real struct file is hidden behind the overlays struct file. So, any file->f_mode manipulations are not reflected on the real struct file. Open the file again in read mode if original file cannot be read, read and calculate the hash. Signed-off-by: Goldwyn Rodrigues Cc: stable@vger.kernel.org (linux-4.19) Signed-off-by: Mimi Zohar Signed-off-by: Sasha Levin --- security/integrity/ima/ima_crypto.c | 54 ++++++++++++++++++----------- 1 file changed, 34 insertions(+), 20 deletions(-) diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c index cb041af9eddb2..af680b5b678a4 100644 --- a/security/integrity/ima/ima_crypto.c +++ b/security/integrity/ima/ima_crypto.c @@ -232,7 +232,7 @@ static int ima_calc_file_hash_atfm(struct file *file, { loff_t i_size, offset; char *rbuf[2] = { NULL, }; - int rc, read = 0, rbuf_len, active = 0, ahash_rc = 0; + int rc, rbuf_len, active = 0, ahash_rc = 0; struct ahash_request *req; struct scatterlist sg[1]; struct ahash_completion res; @@ -279,11 +279,6 @@ static int ima_calc_file_hash_atfm(struct file *file, &rbuf_size[1], 0); } - if (!(file->f_mode & FMODE_READ)) { - file->f_mode |= FMODE_READ; - read = 1; - } - for (offset = 0; offset < i_size; offset += rbuf_len) { if (!rbuf[1] && offset) { /* Not using two buffers, and it is not the first @@ -322,8 +317,6 @@ static int ima_calc_file_hash_atfm(struct file *file, /* wait for the last update request to complete */ rc = ahash_wait(ahash_rc, &res); out3: - if (read) - file->f_mode &= ~FMODE_READ; ima_free_pages(rbuf[0], rbuf_size[0]); ima_free_pages(rbuf[1], rbuf_size[1]); out2: @@ -358,7 +351,7 @@ static int ima_calc_file_hash_tfm(struct file *file, { loff_t i_size, offset = 0; char *rbuf; - int rc, read = 0; + int rc; SHASH_DESC_ON_STACK(shash, tfm); shash->tfm = tfm; @@ -379,11 +372,6 @@ static int ima_calc_file_hash_tfm(struct file *file, if (!rbuf) return -ENOMEM; - if (!(file->f_mode & FMODE_READ)) { - file->f_mode |= FMODE_READ; - read = 1; - } - while (offset < i_size) { int rbuf_len; @@ -400,8 +388,6 @@ static int ima_calc_file_hash_tfm(struct file *file, if (rc) break; } - if (read) - file->f_mode &= ~FMODE_READ; kfree(rbuf); out: if (!rc) @@ -442,6 +428,8 @@ int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash) { loff_t i_size; int rc; + struct file *f = file; + bool new_file_instance = false, modified_flags = false; /* * For consistency, fail file's opened with the O_DIRECT flag on @@ -453,15 +441,41 @@ int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash) return -EINVAL; } - i_size = i_size_read(file_inode(file)); + /* Open a new file instance in O_RDONLY if we cannot read */ + if (!(file->f_mode & FMODE_READ)) { + int flags = file->f_flags & ~(O_WRONLY | O_APPEND | + O_TRUNC | O_CREAT | O_NOCTTY | O_EXCL); + flags |= O_RDONLY; + f = dentry_open(&file->f_path, flags, file->f_cred); + if (IS_ERR(f)) { + /* + * Cannot open the file again, lets modify f_flags + * of original and continue + */ + pr_info_ratelimited("Unable to reopen file for reading.\n"); + f = file; + f->f_flags |= FMODE_READ; + modified_flags = true; + } else { + new_file_instance = true; + } + } + + i_size = i_size_read(file_inode(f)); if (ima_ahash_minsize && i_size >= ima_ahash_minsize) { - rc = ima_calc_file_ahash(file, hash); + rc = ima_calc_file_ahash(f, hash); if (!rc) - return 0; + goto out; } - return ima_calc_file_shash(file, hash); + rc = ima_calc_file_shash(f, hash); +out: + if (new_file_instance) + fput(f); + else if (modified_flags) + f->f_flags &= ~FMODE_READ; + return rc; } /* -- 2.20.1