From patchwork Fri Jul 17 17:42:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 11670899 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 2455A161F for ; Fri, 17 Jul 2020 17:43:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 06728207EA for ; Fri, 17 Jul 2020 17:43:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="U67vlHLw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728109AbgGQRnU (ORCPT ); Fri, 17 Jul 2020 13:43:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45908 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728071AbgGQRnR (ORCPT ); Fri, 17 Jul 2020 13:43:17 -0400 Received: from mail-pl1-x643.google.com (mail-pl1-x643.google.com [IPv6:2607:f8b0:4864:20::643]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5DBB6C0619DC for ; Fri, 17 Jul 2020 10:43:17 -0700 (PDT) Received: by mail-pl1-x643.google.com with SMTP id x9so5767286plr.2 for ; Fri, 17 Jul 2020 10:43:17 -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=3IXKqn7F4SFd0yKw5rLsiOBOS5nVWQ+gMXsoHtaNrvM=; b=U67vlHLwnlPfLwmDS1R8C5bGzWkJxePdNnEspX2sTBiA4ok7EgEBR6xtTLhbVlsxLp ATjWtMTbSDXn6e1cBgpJrsFO/Y6y48VUplzFt7erDVtM5UxdnJKscaYAfHfv4t/nO6uJ 1BubEajP8c3in43OGBwoNCOhckse5w2aFUjVg= 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=3IXKqn7F4SFd0yKw5rLsiOBOS5nVWQ+gMXsoHtaNrvM=; b=hjifvakITW8xTpM9uLt5s7+m8ue9UCbk0VW+dJSOs794OhH9yX7fUB9wqvcbYBkeDo nqgQhoWIB1InWiXNMActuIB5iubu1w8430bWxKhygne5ff3tsR7cR4R5yj//R0N6tE74 gHlmPqlqyNmW4lmol07DGv9menctjIdBvv0NTzv0soJz5D4UWGjXaxibVRpQ+vPJ+FQu cWsmXV4BaxXCCUcNEitI1Df1/30dXGNl+U+nHGCajQ3M5eYr72JgeYvrGy+PKAW/Ts5g rYpF5a9RuSVAmwKeG8y0IyQVObTooa1qVQ1fURrFTWOZ5wkeK5y43B5eIjTb+ZjlPbWH Ri6Q== X-Gm-Message-State: AOAM533psm/DqnCm0wvXuk/PywowjGzLhLqON3/7Qjh/LqMteb6A4Rf1 GdV2lOVKQ5WodDIOmItsSV8jVQ== X-Google-Smtp-Source: ABdhPJzUkt826uAizvlg3lqTuwsp8AQf47DSZ/Zd4XzY23H6UE3ZjgLkX0UcfeKzR6N5EFvD5P/fxQ== X-Received: by 2002:a17:90b:916:: with SMTP id bo22mr11237160pjb.100.1595007796907; Fri, 17 Jul 2020 10:43:16 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id t126sm8219227pfd.214.2020.07.17.10.43.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 17 Jul 2020 10:43:13 -0700 (PDT) From: Kees Cook To: Scott Branden Cc: Kees Cook , stable@vger.kernel.org, Mimi Zohar , Matthew Wilcox , James Morris , Luis Chamberlain , Greg Kroah-Hartman , "Rafael J. Wysocki" , Alexander Viro , Jessica Yu , Dmitry Kasatkin , "Serge E. Hallyn" , Casey Schaufler , "Eric W. Biederman" , Peter Zijlstra , Matthew Garrett , David Howells , Mauro Carvalho Chehab , Randy Dunlap , "Joel Fernandes (Google)" , KP Singh , Dave Olsthoorn , Hans de Goede , Peter Jones , Andrew Morton , Stephen Boyd , Paul Moore , Stephen Smalley , linux-security-module@vger.kernel.org, linux-integrity@vger.kernel.org, selinux@vger.kernel.org, linux-fsdevel@vger.kernel.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH 02/13] fs/kernel_read_file: Remove FIRMWARE_PREALLOC_BUFFER enum Date: Fri, 17 Jul 2020 10:42:57 -0700 Message-Id: <20200717174309.1164575-3-keescook@chromium.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200717174309.1164575-1-keescook@chromium.org> References: <20200717174309.1164575-1-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 FIRMWARE_PREALLOC_BUFFER is a "how", not a "what", and confuses the LSMs that are interested in filtering between types of things. The "how" should be an internal detail made uninteresting to the LSMs. Fixes: a098ecd2fa7d ("firmware: support loading into a pre-allocated buffer") Fixes: fd90bc559bfb ("ima: based on policy verify firmware signatures (pre-allocated buffer)") Fixes: 4f0496d8ffa3 ("ima: based on policy warn about loading firmware (pre-allocated buffer)") Cc: stable@vger.kernel.org Signed-off-by: Kees Cook Acked-by: Scott Branden --- To aid in backporting, this change is made before moving kernel_read_file() to separate header/source files. --- drivers/base/firmware_loader/main.c | 5 ++--- fs/exec.c | 7 ++++--- include/linux/fs.h | 2 +- kernel/module.c | 2 +- security/integrity/digsig.c | 2 +- security/integrity/ima/ima_fs.c | 2 +- security/integrity/ima/ima_main.c | 6 ++---- 7 files changed, 12 insertions(+), 14 deletions(-) diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c index ca871b13524e..c2f57cedcd6f 100644 --- a/drivers/base/firmware_loader/main.c +++ b/drivers/base/firmware_loader/main.c @@ -465,14 +465,12 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv, int i, len; int rc = -ENOENT; char *path; - enum kernel_read_file_id id = READING_FIRMWARE; size_t msize = INT_MAX; void *buffer = NULL; /* Already populated data member means we're loading into a buffer */ if (!decompress && fw_priv->data) { buffer = fw_priv->data; - id = READING_FIRMWARE_PREALLOC_BUFFER; msize = fw_priv->allocated_size; } @@ -496,7 +494,8 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv, /* load firmware files from the mount namespace of init */ rc = kernel_read_file_from_path_initns(path, &buffer, - &size, msize, id); + &size, msize, + READING_FIRMWARE); if (rc) { if (rc != -ENOENT) dev_warn(device, "loading %s failed with error %d\n", diff --git a/fs/exec.c b/fs/exec.c index e6e8a9a70327..2bf549757ce7 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -927,6 +927,7 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size, { 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) @@ -950,8 +951,8 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size, goto out; } - if (id != READING_FIRMWARE_PREALLOC_BUFFER) - *buf = vmalloc(i_size); + if (!*buf) + *buf = allocated = vmalloc(i_size); if (!*buf) { ret = -ENOMEM; goto out; @@ -980,7 +981,7 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size, out_free: if (ret < 0) { - if (id != READING_FIRMWARE_PREALLOC_BUFFER) { + if (allocated) { vfree(*buf); *buf = NULL; } diff --git a/include/linux/fs.h b/include/linux/fs.h index 3f881a892ea7..95fc775ed937 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2993,10 +2993,10 @@ static inline void i_readcount_inc(struct inode *inode) #endif extern int do_pipe_flags(int *, int); +/* This is a list of *what* is being read, not *how*. */ #define __kernel_read_file_id(id) \ id(UNKNOWN, unknown) \ id(FIRMWARE, firmware) \ - id(FIRMWARE_PREALLOC_BUFFER, firmware) \ id(FIRMWARE_EFI_EMBEDDED, firmware) \ id(MODULE, kernel-module) \ id(KEXEC_IMAGE, kexec-image) \ diff --git a/kernel/module.c b/kernel/module.c index 0c6573b98c36..26105148f4d2 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -3988,7 +3988,7 @@ SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags) { struct load_info info = { }; loff_t size; - void *hdr; + void *hdr = NULL; int err; err = may_init_module(); diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c index e9cbadade74b..ac02b7632353 100644 --- a/security/integrity/digsig.c +++ b/security/integrity/digsig.c @@ -169,7 +169,7 @@ int __init integrity_add_key(const unsigned int id, const void *data, int __init integrity_load_x509(const unsigned int id, const char *path) { - void *data; + void *data = NULL; loff_t size; int rc; key_perm_t perm; diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c index e3fcad871861..15a44c5022f7 100644 --- a/security/integrity/ima/ima_fs.c +++ b/security/integrity/ima/ima_fs.c @@ -272,7 +272,7 @@ static const struct file_operations ima_ascii_measurements_ops = { static ssize_t ima_read_policy(char *path) { - void *data; + void *data = NULL; char *datap; loff_t size; int rc, pathlen = strlen(path); diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index c1583d98c5e5..f80ee4ce4669 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -611,19 +611,17 @@ void ima_post_path_mknod(struct dentry *dentry) int ima_read_file(struct file *file, enum kernel_read_file_id read_id) { /* - * READING_FIRMWARE_PREALLOC_BUFFER - * * Do devices using pre-allocated memory run the risk of the * firmware being accessible to the device prior to the completion * of IMA's signature verification any more than when using two - * buffers? + * buffers? It may be desirable to include the buffer address + * in this API and walk all the dma_map_single() mappings to check. */ return 0; } const int read_idmap[READING_MAX_ID] = { [READING_FIRMWARE] = FIRMWARE_CHECK, - [READING_FIRMWARE_PREALLOC_BUFFER] = FIRMWARE_CHECK, [READING_MODULE] = MODULE_CHECK, [READING_KEXEC_IMAGE] = KEXEC_KERNEL_CHECK, [READING_KEXEC_INITRAMFS] = KEXEC_INITRAMFS_CHECK,