From patchwork Tue Jun 9 22:56:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Scott Branden X-Patchwork-Id: 11596675 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 B3D4492A for ; Tue, 9 Jun 2020 22:57:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 961F620835 for ; Tue, 9 Jun 2020 22:57:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b="VUp4QVO/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728936AbgFIW53 (ORCPT ); Tue, 9 Jun 2020 18:57:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60702 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728683AbgFIW5M (ORCPT ); Tue, 9 Jun 2020 18:57:12 -0400 Received: from mail-pf1-x444.google.com (mail-pf1-x444.google.com [IPv6:2607:f8b0:4864:20::444]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DA257C08C5C2 for ; Tue, 9 Jun 2020 15:57:11 -0700 (PDT) Received: by mail-pf1-x444.google.com with SMTP id d66so217420pfd.6 for ; Tue, 09 Jun 2020 15:57:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=GhKodXafnqLJk+aH5Hxa5zCb8c2nq9PYG1JmfapgHFE=; b=VUp4QVO/DaLqlmRzPCPAy0xho6fXQ2qiMkMM8YEv5P8oWzFeK3ty32NlRSdulaz/dy cGZr6YOfTjt6hYZVkNf5GzogEFzde52IxYgdHRl1gxC1JbKwHQWMYXgHG2CXHcrl4oAE iYXauEg53tojwMQS0YMfVpEIZ3niNPGQiuXAM= 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; bh=GhKodXafnqLJk+aH5Hxa5zCb8c2nq9PYG1JmfapgHFE=; b=lIWd5jYY0LmonsrbI4rxLSLHTCkfYPHlX1tL77u9FlHI6YgshxdalZ1lMgjO+9gPb7 TK1stF+sxNH39ZACkk7W9CS8z58XT/ELE8XzWYK7NX+Sc3TTxLln74wS2skd3PKt9VIh qlv6ijI56vjM8hZ9dvR/nyu1BRVgWIWJQKxhXfa77xBwJc90qPNfh1YWA8lisfrJvWq1 TRXx/2G2diUB+meCa2LqojojzOhTyrIqtxOc7adOUIeYN4GFMPdyrznVWHKAPtW/dNwM 63V5dN+Kf5Gj8cKBrWifqVGOQZWlJKthJ97utzeAGXk0EXRNCWt64nEA4s90PLvnqYjN KjVA== X-Gm-Message-State: AOAM531oSPD7ubRUZZ95c0qgZohczWMjijZwTHhdZDjaKbe3IjDnHBJt p7QMw4YhqfLJdrG1n8kZu1/8kA== X-Google-Smtp-Source: ABdhPJzunrBENd8Gt6Atjck/9sEOv5kmJocCR172m7pZyT7iDNxK1yUwX+CwbRU4PIabfOkGcTJ08A== X-Received: by 2002:a62:fc52:: with SMTP id e79mr91278pfh.5.1591743431293; Tue, 09 Jun 2020 15:57:11 -0700 (PDT) Received: from lbrmn-lnxub113.broadcom.net ([192.19.228.250]) by smtp.gmail.com with ESMTPSA id p8sm9104978pgs.29.2020.06.09.15.57.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 09 Jun 2020 15:57:10 -0700 (PDT) From: Scott Branden To: Luis Chamberlain , Wolfram Sang , Greg Kroah-Hartman , David Brown , Alexander Viro , Shuah Khan , bjorn.andersson@linaro.org, Shuah Khan , Arnd Bergmann Cc: Mimi Zohar , "Rafael J . Wysocki" , linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-fsdevel@vger.kernel.org, BCM Kernel Feedback , Olof Johansson , Andrew Morton , Dan Carpenter , Colin Ian King , Kees Cook , Takashi Iwai , linux-kselftest@vger.kernel.org, Andy Gross , linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, Scott Branden Subject: [PATCH v8 1/8] fs: introduce kernel_pread_file* support Date: Tue, 9 Jun 2020 15:56:49 -0700 Message-Id: <20200609225656.18663-2-scott.branden@broadcom.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200609225656.18663-1-scott.branden@broadcom.com> References: <20200609225656.18663-1-scott.branden@broadcom.com> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add kernel_pread_file* support to kernel to allow for partial read of files with an offset into the file. Signed-off-by: Scott Branden --- fs/exec.c | 93 ++++++++++++++++++++++++++++++++++------------ include/linux/fs.h | 15 ++++++++ 2 files changed, 85 insertions(+), 23 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index 7b7cbb180785..c557b4b31d0f 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -927,10 +927,14 @@ 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; +int kernel_pread_file(struct file *file, void **buf, loff_t *size, + loff_t max_size, loff_t pos, + enum kernel_read_file_id id) +{ + loff_t alloc_size; + loff_t buf_pos; + loff_t read_end; + loff_t i_size; ssize_t bytes = 0; int ret; @@ -950,21 +954,32 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size, ret = -EINVAL; goto out; } - if (i_size > SIZE_MAX || (max_size > 0 && i_size > max_size)) { + + /* Default read to end of file */ + read_end = i_size; + + /* Allow reading partial portion of file */ + if ((id == READING_FIRMWARE_PARTIAL_READ) && + (i_size > (pos + max_size))) + read_end = pos + max_size; + + alloc_size = read_end - pos; + if (i_size > SIZE_MAX || (max_size > 0 && alloc_size > max_size)) { ret = -EFBIG; goto out; } - if (id != READING_FIRMWARE_PREALLOC_BUFFER) - *buf = vmalloc(i_size); + if ((id != READING_FIRMWARE_PARTIAL_READ) && + (id != READING_FIRMWARE_PREALLOC_BUFFER)) + *buf = vmalloc(alloc_size); if (!*buf) { ret = -ENOMEM; goto out; } - pos = 0; - while (pos < i_size) { - bytes = kernel_read(file, *buf + pos, i_size - pos, &pos); + buf_pos = 0; + while (pos < read_end) { + bytes = kernel_read(file, *buf + buf_pos, read_end - pos, &pos); if (bytes < 0) { ret = bytes; goto out_free; @@ -972,20 +987,23 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size, if (bytes == 0) break; + + buf_pos += bytes; } - if (pos != i_size) { + if (pos != read_end) { ret = -EIO; goto out_free; } - ret = security_kernel_post_read_file(file, *buf, i_size, id); + ret = security_kernel_post_read_file(file, *buf, alloc_size, id); if (!ret) *size = pos; out_free: if (ret < 0) { - if (id != READING_FIRMWARE_PREALLOC_BUFFER) { + if ((id != READING_FIRMWARE_PARTIAL_READ) && + (id != READING_FIRMWARE_PREALLOC_BUFFER)) { vfree(*buf); *buf = NULL; } @@ -995,10 +1013,18 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size, allow_write_access(file); return ret; } + +int kernel_read_file(struct file *file, void **buf, loff_t *size, + loff_t max_size, enum kernel_read_file_id id) +{ + return kernel_pread_file(file, buf, size, max_size, 0, id); +} 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) +int kernel_pread_file_from_path(const char *path, void **buf, + loff_t *size, + loff_t max_size, loff_t pos, + enum kernel_read_file_id id) { struct file *file; int ret; @@ -1010,15 +1036,22 @@ int kernel_read_file_from_path(const char *path, void **buf, loff_t *size, if (IS_ERR(file)) return PTR_ERR(file); - ret = kernel_read_file(file, buf, size, max_size, id); + ret = kernel_pread_file(file, buf, size, max_size, pos, id); fput(file); return ret; } + +int kernel_read_file_from_path(const char *path, void **buf, loff_t *size, + loff_t max_size, enum kernel_read_file_id id) +{ + return kernel_pread_file_from_path(path, buf, size, max_size, 0, id); +} 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) +int kernel_pread_file_from_path_initns(const char *path, void **buf, + loff_t *size, + loff_t max_size, loff_t pos, + enum kernel_read_file_id id) { struct file *file; struct path root; @@ -1036,14 +1069,22 @@ int kernel_read_file_from_path_initns(const char *path, void **buf, if (IS_ERR(file)) return PTR_ERR(file); - ret = kernel_read_file(file, buf, size, max_size, id); + ret = kernel_pread_file(file, buf, size, max_size, pos, id); fput(file); return ret; } + +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) +{ + return kernel_pread_file_from_path_initns(path, buf, size, max_size, 0, id); +} 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) +int kernel_pread_file_from_fd(int fd, void **buf, loff_t *size, + loff_t max_size, loff_t pos, + enum kernel_read_file_id id) { struct fd f = fdget(fd); int ret = -EBADF; @@ -1051,11 +1092,17 @@ int kernel_read_file_from_fd(int fd, void **buf, loff_t *size, loff_t max_size, if (!f.file) goto out; - ret = kernel_read_file(f.file, buf, size, max_size, id); + ret = kernel_pread_file(f.file, buf, size, max_size, pos, id); out: fdput(f); return ret; } + +int kernel_read_file_from_fd(int fd, void **buf, loff_t *size, loff_t max_size, + enum kernel_read_file_id id) +{ + return kernel_pread_file_from_fd(fd, buf, size, max_size, 0, id); +} EXPORT_SYMBOL_GPL(kernel_read_file_from_fd); #if defined(CONFIG_HAVE_AOUT) || defined(CONFIG_BINFMT_FLAT) || \ diff --git a/include/linux/fs.h b/include/linux/fs.h index 951862b1211b..ab715559cf3c 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3012,6 +3012,7 @@ extern int do_pipe_flags(int *, int); #define __kernel_read_file_id(id) \ id(UNKNOWN, unknown) \ id(FIRMWARE, firmware) \ + id(FIRMWARE_PARTIAL_READ, firmware) \ id(FIRMWARE_PREALLOC_BUFFER, firmware) \ id(FIRMWARE_EFI_EMBEDDED, firmware) \ id(MODULE, kernel-module) \ @@ -3040,12 +3041,26 @@ static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id) return kernel_read_file_str[id]; } +int kernel_pread_file(struct file *file, void **buf, loff_t *size, + loff_t pos, loff_t max_size, + enum kernel_read_file_id id); extern int kernel_read_file(struct file *, void **, loff_t *, loff_t, enum kernel_read_file_id); +int kernel_pread_file_from_path(const char *path, void **buf, + loff_t *size, loff_t pos, + loff_t max_size, + enum kernel_read_file_id id); extern int kernel_read_file_from_path(const char *, void **, loff_t *, loff_t, enum kernel_read_file_id); +int kernel_pread_file_from_path_initns(const char *path, void **buf, + loff_t *size, loff_t pos, + loff_t max_size, + enum kernel_read_file_id id); extern int kernel_read_file_from_path_initns(const char *, void **, loff_t *, loff_t, enum kernel_read_file_id); +int kernel_pread_file_from_fd(int fd, void **buf, loff_t *size, + loff_t pos, loff_t max_size, + enum kernel_read_file_id id); extern int kernel_read_file_from_fd(int, void **, loff_t *, loff_t, enum kernel_read_file_id); extern ssize_t kernel_read(struct file *, void *, size_t, loff_t *);