From patchwork Wed Jul 29 17:58:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 11691547 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 91F581392 for ; Wed, 29 Jul 2020 18:00:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 781B920809 for ; Wed, 29 Jul 2020 18:00:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="Uy1qxMG9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728096AbgG2SAF (ORCPT ); Wed, 29 Jul 2020 14:00:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35682 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727827AbgG2R7A (ORCPT ); Wed, 29 Jul 2020 13:59:00 -0400 Received: from mail-pj1-x1043.google.com (mail-pj1-x1043.google.com [IPv6:2607:f8b0:4864:20::1043]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 421EEC061794 for ; Wed, 29 Jul 2020 10:59:00 -0700 (PDT) Received: by mail-pj1-x1043.google.com with SMTP id k1so2233386pjt.5 for ; Wed, 29 Jul 2020 10:59:00 -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=s8pBSpCBzAxEXSHFMED25Y5ODq87rGH8b/wr0X9QC7I=; b=Uy1qxMG9Wk7KhOJd3h1FBwTDF5og6PjBAQI16Z27ZpZm2EIrFW3BdRtpDli8mZi1t6 2NNjargrYHFlYLP8pNZ29iVEsGle8JrqmrtsHwy/+EiM9ae/EoP6+HBD5yz/FBTmfY5o YT+z+TKhc/UG0zOYcimMA/QrptC9N69IWpT60= 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=s8pBSpCBzAxEXSHFMED25Y5ODq87rGH8b/wr0X9QC7I=; b=nXYsQ1ZHTwQNuwzP0YNCb7fewAbKU0WIyZ/U3bCAQ0FtPYsriJZuth9KHikEk2cqfz 32M3yHVSRtjFfrma7f2SBeIZKh/PSXya8rxfaqn2s7L2EABvbIevIvVg8hK4kE6e0XZd 0Mj8dhqzdVi2bu6wOZtFIbCbDv+ohYQMr5yFmwAjX4eyN45ODws71nQv0+oBLS0uXrDX jcvPD61j34gWkMUkgwne1yud/fKkADz8TqiH9SJzcnBhNLUrcVMS1CRotSqAeaEInSsA Jm2+vscccfVsdwBWXn9bOYSo/HwY2dGG61WrXmHL1LcorSEw0Q3v6ZLgSSlZxFdyK0be uXDQ== X-Gm-Message-State: AOAM533D5F3GzJdnZBaZphJRoRF7uCDuqYOgp7cKmmMy4KL/YLJxyhAa KdQfCQdLTnni/pJ6afMjiFrAww== X-Google-Smtp-Source: ABdhPJzo9IxoT9gvuXx2GpK4yoZzBFJYjOX4Gn6EU8vWiGKG8RTXVOjsQFEjv28d+YZFT5W01YafVw== X-Received: by 2002:a17:902:7086:: with SMTP id z6mr27406701plk.4.1596045539786; Wed, 29 Jul 2020 10:58:59 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id u2sm3138576pfl.21.2020.07.29.10.58.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 29 Jul 2020 10:58:58 -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 05/17] fs/kernel_read_file: Split into separate source file Date: Wed, 29 Jul 2020 10:58:33 -0700 Message-Id: <20200729175845.1745471-6-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 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org These routines are used in places outside of exec(2), so in preparation for refactoring them, move them into a separate source file, fs/kernel_read_file.c. Acked-by: Scott Branden Reviewed-by: Mimi Zohar Reviewed-by: Luis Chamberlain Signed-off-by: Kees Cook --- fs/Makefile | 3 +- fs/exec.c | 132 ---------------------------------------- fs/kernel_read_file.c | 138 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 140 insertions(+), 133 deletions(-) create mode 100644 fs/kernel_read_file.c diff --git a/fs/Makefile b/fs/Makefile index 2ce5112b02c8..a05fc247b2a7 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -13,7 +13,8 @@ obj-y := open.o read_write.o file_table.o super.o \ seq_file.o xattr.o libfs.o fs-writeback.o \ pnode.o splice.o sync.o utimes.o d_path.o \ stack.o fs_struct.o statfs.o fs_pin.o nsfs.o \ - fs_types.o fs_context.o fs_parser.o fsopen.o + fs_types.o fs_context.o fs_parser.o fsopen.o \ + kernel_read_file.o ifeq ($(CONFIG_BLOCK),y) obj-y += buffer.o block_dev.o direct-io.o mpage.o diff --git a/fs/exec.c b/fs/exec.c index 07a7fe9ac5be..d619b79aab30 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -923,138 +923,6 @@ struct file *open_exec(const char *name) } EXPORT_SYMBOL(open_exec); -int kernel_read_file(struct file *file, void **buf, loff_t *size, - loff_t max_size, enum kernel_read_file_id id) -{ - loff_t i_size, pos; - ssize_t bytes = 0; - void *allocated = NULL; - int ret; - - if (!S_ISREG(file_inode(file)->i_mode) || max_size < 0) - return -EINVAL; - - ret = deny_write_access(file); - if (ret) - return ret; - - ret = security_kernel_read_file(file, id); - if (ret) - goto out; - - i_size = i_size_read(file_inode(file)); - if (i_size <= 0) { - ret = -EINVAL; - goto out; - } - if (i_size > SIZE_MAX || (max_size > 0 && i_size > max_size)) { - ret = -EFBIG; - goto out; - } - - if (!*buf) - *buf = allocated = vmalloc(i_size); - if (!*buf) { - ret = -ENOMEM; - goto out; - } - - pos = 0; - while (pos < i_size) { - bytes = kernel_read(file, *buf + pos, i_size - pos, &pos); - if (bytes < 0) { - ret = bytes; - goto out_free; - } - - if (bytes == 0) - break; - } - - if (pos != i_size) { - ret = -EIO; - goto out_free; - } - - ret = security_kernel_post_read_file(file, *buf, i_size, id); - if (!ret) - *size = pos; - -out_free: - if (ret < 0) { - if (allocated) { - vfree(*buf); - *buf = NULL; - } - } - -out: - allow_write_access(file); - return ret; -} -EXPORT_SYMBOL_GPL(kernel_read_file); - -int kernel_read_file_from_path(const char *path, void **buf, loff_t *size, - loff_t max_size, enum kernel_read_file_id id) -{ - struct file *file; - int ret; - - if (!path || !*path) - return -EINVAL; - - file = filp_open(path, O_RDONLY, 0); - if (IS_ERR(file)) - return PTR_ERR(file); - - ret = kernel_read_file(file, buf, size, max_size, id); - fput(file); - return ret; -} -EXPORT_SYMBOL_GPL(kernel_read_file_from_path); - -int kernel_read_file_from_path_initns(const char *path, void **buf, - loff_t *size, loff_t max_size, - enum kernel_read_file_id id) -{ - struct file *file; - struct path root; - int ret; - - if (!path || !*path) - return -EINVAL; - - task_lock(&init_task); - get_fs_root(init_task.fs, &root); - task_unlock(&init_task); - - file = file_open_root(root.dentry, root.mnt, path, O_RDONLY, 0); - path_put(&root); - if (IS_ERR(file)) - return PTR_ERR(file); - - ret = kernel_read_file(file, buf, size, max_size, id); - fput(file); - return ret; -} -EXPORT_SYMBOL_GPL(kernel_read_file_from_path_initns); - -int kernel_read_file_from_fd(int fd, void **buf, loff_t *size, loff_t max_size, - enum kernel_read_file_id id) -{ - struct fd f = fdget(fd); - int ret = -EBADF; - - if (!f.file) - goto out; - - ret = kernel_read_file(f.file, buf, size, max_size, id); -out: - fdput(f); - return ret; -} -EXPORT_SYMBOL_GPL(kernel_read_file_from_fd); - #if defined(CONFIG_HAVE_AOUT) || defined(CONFIG_BINFMT_FLAT) || \ defined(CONFIG_BINFMT_ELF_FDPIC) ssize_t read_code(struct file *file, unsigned long addr, loff_t pos, size_t len) diff --git a/fs/kernel_read_file.c b/fs/kernel_read_file.c new file mode 100644 index 000000000000..54d972d4befc --- /dev/null +++ b/fs/kernel_read_file.c @@ -0,0 +1,138 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include +#include +#include +#include + +int kernel_read_file(struct file *file, void **buf, loff_t *size, + loff_t max_size, enum kernel_read_file_id id) +{ + loff_t i_size, pos; + ssize_t bytes = 0; + void *allocated = NULL; + int ret; + + if (!S_ISREG(file_inode(file)->i_mode) || max_size < 0) + return -EINVAL; + + ret = deny_write_access(file); + if (ret) + return ret; + + ret = security_kernel_read_file(file, id); + if (ret) + goto out; + + i_size = i_size_read(file_inode(file)); + if (i_size <= 0) { + ret = -EINVAL; + goto out; + } + if (i_size > SIZE_MAX || (max_size > 0 && i_size > max_size)) { + ret = -EFBIG; + goto out; + } + + if (!*buf) + *buf = allocated = vmalloc(i_size); + if (!*buf) { + ret = -ENOMEM; + goto out; + } + + pos = 0; + while (pos < i_size) { + bytes = kernel_read(file, *buf + pos, i_size - pos, &pos); + if (bytes < 0) { + ret = bytes; + goto out_free; + } + + if (bytes == 0) + break; + } + + if (pos != i_size) { + ret = -EIO; + goto out_free; + } + + ret = security_kernel_post_read_file(file, *buf, i_size, id); + if (!ret) + *size = pos; + +out_free: + if (ret < 0) { + if (allocated) { + vfree(*buf); + *buf = NULL; + } + } + +out: + allow_write_access(file); + return ret; +} +EXPORT_SYMBOL_GPL(kernel_read_file); + +int kernel_read_file_from_path(const char *path, void **buf, loff_t *size, + loff_t max_size, enum kernel_read_file_id id) +{ + struct file *file; + int ret; + + if (!path || !*path) + return -EINVAL; + + file = filp_open(path, O_RDONLY, 0); + if (IS_ERR(file)) + return PTR_ERR(file); + + ret = kernel_read_file(file, buf, size, max_size, id); + fput(file); + return ret; +} +EXPORT_SYMBOL_GPL(kernel_read_file_from_path); + +int kernel_read_file_from_path_initns(const char *path, void **buf, + loff_t *size, loff_t max_size, + enum kernel_read_file_id id) +{ + struct file *file; + struct path root; + int ret; + + if (!path || !*path) + return -EINVAL; + + task_lock(&init_task); + get_fs_root(init_task.fs, &root); + task_unlock(&init_task); + + file = file_open_root(root.dentry, root.mnt, path, O_RDONLY, 0); + path_put(&root); + if (IS_ERR(file)) + return PTR_ERR(file); + + ret = kernel_read_file(file, buf, size, max_size, id); + fput(file); + return ret; +} +EXPORT_SYMBOL_GPL(kernel_read_file_from_path_initns); + +int kernel_read_file_from_fd(int fd, void **buf, loff_t *size, loff_t max_size, + enum kernel_read_file_id id) +{ + struct fd f = fdget(fd); + int ret = -EBADF; + + if (!f.file) + goto out; + + ret = kernel_read_file(f.file, buf, size, max_size, id); +out: + fdput(f); + return ret; +} +EXPORT_SYMBOL_GPL(kernel_read_file_from_fd);