From patchwork Fri Jul 24 21:36:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 11684551 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 EF179618 for ; Fri, 24 Jul 2020 21:38:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D1A4920836 for ; Fri, 24 Jul 2020 21:38:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="fKCBbMIZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726862AbgGXVig (ORCPT ); Fri, 24 Jul 2020 17:38:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57758 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726826AbgGXVgq (ORCPT ); Fri, 24 Jul 2020 17:36:46 -0400 Received: from mail-pl1-x641.google.com (mail-pl1-x641.google.com [IPv6:2607:f8b0:4864:20::641]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 60B51C0619E7 for ; Fri, 24 Jul 2020 14:36:46 -0700 (PDT) Received: by mail-pl1-x641.google.com with SMTP id b9so5295079plx.6 for ; Fri, 24 Jul 2020 14:36:46 -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=YLy0ZgqcjQnksBvi3DviLt6cbR749pq+3Sg+gKabpfk=; b=fKCBbMIZ3wdYF10uVKEMHpjA/Pyc5cd2gK6PF4DES9Hf/TmROG98SwIzq1cz3ecKbE 4V95zYjMGsp3xFoSuaYl9TLiiKDAAoOMUx0gTdDeVtwLSn8fJo9z9X12CyOAVZQ+m6xX /jodBAjN9zbIl5vwaKZj5rSbmxaQztk2wdscQ= 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=YLy0ZgqcjQnksBvi3DviLt6cbR749pq+3Sg+gKabpfk=; b=dYTFoH3uGdEl8QHGxuGZ+DI5RstHCq1GvWtrAizHEkJfckIlck8pk6WSs1xNkxek3u NTWf0X5IyiAup2erWpUiTpof8sUG1oaRpcGXf+eb8z68zB8D+JuSzynvHnwMB1vHJoU7 ovHwzlmVbO+wGG/qeG9+4EIynJ63UzyCe+/nlh2FbZDesmpyc8L79IfFC0XQlwcPDwct +/ACPGfYI2D9k89h9ziwBp03DGwVnxT5Xvfk2kCzx3MYhLWCiwHH0qWd/xjrSppmyl+q oioseV0Io5OuoRfxIEQNXrkWUMkTi/EEKOZ3TOckpcusOyXnvW7itKwiLRKHRxuwcWqh H9fw== X-Gm-Message-State: AOAM532c35DINaPePpEnTv+VYilqORI6zyR6MWWgvx7jZhsyWOa9fGcY S4/vgdbJnOg8Rz5xa4YmsBmEIA== X-Google-Smtp-Source: ABdhPJzEgcuNxLo7+nIkeLiK3TbI31y3cje0lQLd0ywUWaYIzS1iN/WrgbXv7zFopX1hiOOQmatiMw== X-Received: by 2002:a17:902:446:: with SMTP id 64mr9977003ple.157.1595626605892; Fri, 24 Jul 2020 14:36:45 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id o17sm6398650pjq.6.2020.07.24.14.36.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 24 Jul 2020 14:36:43 -0700 (PDT) From: Kees Cook To: Greg Kroah-Hartman Cc: Kees Cook , stable@vger.kernel.org, Scott Branden , Mimi Zohar , Luis Chamberlain , 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 v3 04/19] fs/kernel_read_file: Remove FIRMWARE_PREALLOC_BUFFER enum Date: Fri, 24 Jul 2020 14:36:25 -0700 Message-Id: <20200724213640.389191-5-keescook@chromium.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200724213640.389191-1-keescook@chromium.org> References: <20200724213640.389191-1-keescook@chromium.org> MIME-Version: 1.0 Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@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 Acked-by: Scott Branden Signed-off-by: Kees Cook Reviewed-by: Mimi Zohar --- 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,