From patchwork Fri Jun 5 22:59:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Scott Branden X-Patchwork-Id: 208429 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=-9.9 required=3.0 tests=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=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 8C892C433E3 for ; Fri, 5 Jun 2020 23:01:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 65B51206A2 for ; Fri, 5 Jun 2020 23:01:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b="N107Dl1R" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728439AbgFEXAQ (ORCPT ); Fri, 5 Jun 2020 19:00:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46316 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728394AbgFEXAO (ORCPT ); Fri, 5 Jun 2020 19:00:14 -0400 Received: from mail-pl1-x644.google.com (mail-pl1-x644.google.com [IPv6:2607:f8b0:4864:20::644]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D8C00C08C5C3 for ; Fri, 5 Jun 2020 16:00:13 -0700 (PDT) Received: by mail-pl1-x644.google.com with SMTP id m7so4276557plt.5 for ; Fri, 05 Jun 2020 16:00:13 -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=YNH51z2pPdYRKwbT0lKGpbh9OQTXpy9Fw+Gpw3I+u0g=; b=N107Dl1RD0A3r3XNDCFxKEOnLytpj5szJrmkWJyy0+1+HLK/Vd95oWyHhobXtawPrM 09iUhw6Zg8t6/4388rg46y69u2gn3QUQr2vWAjn2XLEwb3WL+uqHb8QXQjETSM1EGiFB SH4dkymS5RiUeOjlB/mEd1QgGQCQlerHfPO58= 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=YNH51z2pPdYRKwbT0lKGpbh9OQTXpy9Fw+Gpw3I+u0g=; b=HaTe+VQUGA48WR4SCDoWGL1VyoruHPfyBNxzfmKoPOCbyBtHR1Bu4gOTUKNlgkGwYK P3m2kv/fuJo2EQUwi0j3B8QDERVf8O2PdX3E1vkbdASJ5LlvvwgTOIQQzAZUapMvliOv mibnpC2CHc7UL38mamaNQENuWl5Pb/LA/C0wHkUWasnM+3w2RId9b+OSf4m0qjfif6/N pySpIaltAa20z+x7lJ+WItv2I5I3p6UyO6N4j5i1nFqZZYV+H7XHsERV/AimRdTOpJKw Q9il5jlACY3Nzr35b9cBv+zIpZcJ9Ruo2Y21Wrd/Zu8F/eysQdSDX6Sssbuwq2Jgzaww TFWg== X-Gm-Message-State: AOAM5325HgFsJnsT6eoFYE6y0qQlDP2lYVyAIsd49SOMm68TuKgioikb z4RpUOcq3nMCFxlW1otYbwKO2A== X-Google-Smtp-Source: ABdhPJwBzexMDGEkU4DIDyOA+icqxKjPI8ibktJna8AbKmzNohV6dFv2TZUE4DM2zAkQLMqLD5PflA== X-Received: by 2002:a17:90a:4495:: with SMTP id t21mr5409327pjg.185.1591398013314; Fri, 05 Jun 2020 16:00:13 -0700 (PDT) Received: from lbrmn-lnxub113.broadcom.net ([192.19.228.250]) by smtp.gmail.com with ESMTPSA id b140sm568974pfb.119.2020.06.05.16.00.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 05 Jun 2020 16:00:12 -0700 (PDT) From: Scott Branden To: Luis Chamberlain , 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 v6 1/8] fs: introduce kernel_pread_file* support Date: Fri, 5 Jun 2020 15:59:52 -0700 Message-Id: <20200605225959.12424-2-scott.branden@broadcom.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200605225959.12424-1-scott.branden@broadcom.com> References: <20200605225959.12424-1-scott.branden@broadcom.com> Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@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 de90a66587ab..e5c241c07b75 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -925,10 +925,15 @@ 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; @@ -948,21 +953,31 @@ 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; @@ -970,14 +985,16 @@ 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; @@ -993,10 +1010,20 @@ 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; @@ -1008,15 +1035,24 @@ 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) +extern 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; @@ -1034,14 +1070,24 @@ 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; @@ -1049,11 +1095,18 @@ 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 fce4b8867224..76d463e4a628 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 *);