From patchwork Sat Jun 6 05:04:51 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Scott Branden X-Patchwork-Id: 11590989 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 3792217C9 for ; Sat, 6 Jun 2020 05:06:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 12ED220835 for ; Sat, 6 Jun 2020 05:06:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b="d7RICQ73" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726554AbgFFFF5 (ORCPT ); Sat, 6 Jun 2020 01:05:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46220 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726626AbgFFFF5 (ORCPT ); Sat, 6 Jun 2020 01:05:57 -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 1CF26C08C5C7 for ; Fri, 5 Jun 2020 22:05:57 -0700 (PDT) Received: by mail-pf1-x441.google.com with SMTP id z64so5943833pfb.1 for ; Fri, 05 Jun 2020 22:05:57 -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=UFMs+pS1mNuYLg2OsoDQ/eCH5ubaRntK3nHk6nEyTVo=; b=d7RICQ73OAKQgCeXCCDVz1Wz1mMz2ptzYeUySZ9uf+jrhxr/ajT8UEX1tgj+l1ANYH YETdieM1F1XyGzdSluSK7dRy1zW/Z3q+UKlfnUhYXBBKosYL4Fo1mjv2rpa2Jdql0FUc LHuSARjO75goSjgiWkyyRIQ6+afn0OfFJfXoA= 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=UFMs+pS1mNuYLg2OsoDQ/eCH5ubaRntK3nHk6nEyTVo=; b=ev7fKZp+glXXSy+Xd2b1TICS5Q8ZI81bYBfXNIZymLFmkEVkZGkZp0rVMSggidqC6h 25zYsk6k7VgWeNyO+/6yrdA5F3pMr2zh/2FVRX0B1udycGDwJO3NgCI769KcAlVXlU7A pGigeXbZyhskPsgaRmowTb3n3BEYHBYURL+f/aGYH+vOKjMbVAYhiqVFZBfQ+1pth3bx yipy3YwGzH91kOSQXsoTvbgNoEUEp46BJOyNP3zN1iAoDFiN7hu3oOKKonFq/JxIWHTx h/5YBkcD88TnkginpxEGPcWiXGhJxKxULSdYws6YjCKkpyTSU+l5swmZQqDOg0WnmFLP 8dkQ== X-Gm-Message-State: AOAM5318PFWp1pdtpKFplmDqIRVdEFzqpmumOyfpyM+Nxh591VHyKgym 4BNXtRRC0ByQMe88sdc9uBMDVA== X-Google-Smtp-Source: ABdhPJy7RD7bjKLK8ou1v5N5tiFd4LwUyBQZf7mn9QgjvIke6zPapaH4lssAciBNu4btJaQYH7tExw== X-Received: by 2002:a63:c44b:: with SMTP id m11mr11793538pgg.404.1591419956426; Fri, 05 Jun 2020 22:05:56 -0700 (PDT) Received: from lbrmn-lnxub113.broadcom.net ([192.19.228.250]) by smtp.gmail.com with ESMTPSA id v8sm1057636pfn.217.2020.06.05.22.05.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 05 Jun 2020 22:05:55 -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 v7 1/8] fs: introduce kernel_pread_file* support Date: Fri, 5 Jun 2020 22:04:51 -0700 Message-Id: <20200606050458.17281-2-scott.branden@broadcom.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200606050458.17281-1-scott.branden@broadcom.com> References: <20200606050458.17281-1-scott.branden@broadcom.com> Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org Add kernel_pread_file* support to kernel to allow for partial read of files with an offset into the file. Existing kernel_read_file functions call new kernel_pread_file functions with offset=0 and opt=KERNEL_PREAD_WHOLE. Signed-off-by: Scott Branden --- fs/exec.c | 95 ++++++++++++++++++++++++++++++++++++---------- include/linux/fs.h | 29 ++++++++++++++ 2 files changed, 103 insertions(+), 21 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index 306fc566171e..751f5ddc7538 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -927,10 +927,15 @@ 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 pos, loff_t max_size, + enum kernel_pread_opt opt, + 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 +955,31 @@ 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 ((opt == KERNEL_PREAD_PART) && + (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); + *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; @@ -972,14 +987,16 @@ 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; @@ -995,10 +1012,20 @@ 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, 0, max_size, + KERNEL_PREAD_WHOLE, 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 pos, + loff_t max_size, + enum kernel_pread_opt opt, + enum kernel_read_file_id id) { struct file *file; int ret; @@ -1010,15 +1037,24 @@ 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, pos, max_size, opt, 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, 0, max_size, + KERNEL_PREAD_WHOLE, 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 pos, + loff_t max_size, + enum kernel_pread_opt opt, + enum kernel_read_file_id id) { struct file *file; struct path root; @@ -1036,14 +1072,24 @@ 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, pos, max_size, opt, 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, 0, max_size, + KERNEL_PREAD_WHOLE, 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 pos, + loff_t max_size, + enum kernel_pread_opt opt, + enum kernel_read_file_id id) { struct fd f = fdget(fd); int ret = -EBADF; @@ -1051,11 +1097,18 @@ 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, pos, max_size, opt, 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, 0, max_size, + KERNEL_PREAD_WHOLE, 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 db604c7bd79c..aee7600958ef 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3048,12 +3048,41 @@ static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id) return kernel_read_file_str[id]; } +/** + * enum kernel_pread_opt - options to control pread file loading behaviour + * + * @KERNEL_PREAD_WHOLE: Only Allow reading of whole file. + * @KERNEL_PREAD_PART: Allow reading part of file. + */ +enum kernel_pread_opt { + KERNEL_PREAD_WHOLE = 0, + KERNEL_PREAD_PART = BIT(0), +}; + +int kernel_pread_file(struct file *file, void **buf, loff_t *size, + loff_t pos, loff_t max_size, + enum kernel_pread_opt opt, + 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_pread_opt opt, + 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_pread_opt opt, + 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_pread_opt opt, + 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 *);