From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 40C00C46467 for ; Mon, 16 Jan 2023 14:15:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232414AbjAPOPC (ORCPT ); Mon, 16 Jan 2023 09:15:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39168 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232161AbjAPONB (ORCPT ); Mon, 16 Jan 2023 09:13:01 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 22D1B2CFFD; Mon, 16 Jan 2023 06:05:01 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id C067560FD2; Mon, 16 Jan 2023 14:04:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0018DC433D2; Mon, 16 Jan 2023 14:04:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673877888; bh=ex2P9mjaiy1ixyTthepQ1ud7mfFrU8jTvWyvwFpzCFQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rFtuqfEhaHkYlh5OTLuqKmYpCf5o4HyD0Gbl0tYY9GDRgSBb/UhN3Z9gDI2cbWD4x bRxVBoVnIPagWIjYEvc1R6dBmsb84bg+4k/AjAtcn2mKwL68udKZlU5fhoHQ+UJpKf v1OotWntRaJuvtKTgToWCXmyCjBShQMwkYjhRkZzwUcsaOozGHOrw7Q446hoyHDFcT BXfbJtYO0DLiYpsIdlu0ahOOUGfFx0zFYwNf6ck56DrfCrEZtqtzmB4AhIDhMcbKvN WCfmFmHEIDUvetgBn/1RIUhW25Loci4mTk3wZVjqk9HnmDzl0+e6rK3ScoAMvYKVYC M95j80IVYZwjA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Kees Cook , Paul Menzel , Jack Rosenthal , Guenter Roeck , Julius Werner , Brian Norris , Stephen Boyd , Greg Kroah-Hartman , Sasha Levin Subject: [PATCH AUTOSEL 5.15 24/24] firmware: coreboot: Check size of table entry and use flex-array Date: Mon, 16 Jan 2023 09:03:59 -0500 Message-Id: <20230116140359.115716-24-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20230116140359.115716-1-sashal@kernel.org> References: <20230116140359.115716-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kees Cook [ Upstream commit 3b293487b8752cc42c1cbf8a0447bc6076c075fa ] The memcpy() of the data following a coreboot_table_entry couldn't be evaluated by the compiler under CONFIG_FORTIFY_SOURCE. To make it easier to reason about, add an explicit flexible array member to struct coreboot_device so the entire entry can be copied at once. Additionally, validate the sizes before copying. Avoids this run-time false positive warning: memcpy: detected field-spanning write (size 168) of single field "&device->entry" at drivers/firmware/google/coreboot_table.c:103 (size 8) Reported-by: Paul Menzel Link: https://lore.kernel.org/all/03ae2704-8c30-f9f0-215b-7cdf4ad35a9a@molgen.mpg.de/ Cc: Jack Rosenthal Cc: Guenter Roeck Cc: Julius Werner Cc: Brian Norris Cc: Stephen Boyd Cc: Greg Kroah-Hartman Signed-off-by: Kees Cook Reviewed-by: Julius Werner Reviewed-by: Guenter Roeck Link: https://lore.kernel.org/r/20230107031406.gonna.761-kees@kernel.org Reviewed-by: Stephen Boyd Reviewed-by: Jack Rosenthal Link: https://lore.kernel.org/r/20230112230312.give.446-kees@kernel.org Signed-off-by: Sasha Levin --- drivers/firmware/google/coreboot_table.c | 9 +++++++-- drivers/firmware/google/coreboot_table.h | 1 + 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/firmware/google/coreboot_table.c b/drivers/firmware/google/coreboot_table.c index 9ca21feb9d45..f3694d347801 100644 --- a/drivers/firmware/google/coreboot_table.c +++ b/drivers/firmware/google/coreboot_table.c @@ -93,7 +93,12 @@ static int coreboot_table_populate(struct device *dev, void *ptr) for (i = 0; i < header->table_entries; i++) { entry = ptr_entry; - device = kzalloc(sizeof(struct device) + entry->size, GFP_KERNEL); + if (entry->size < sizeof(*entry)) { + dev_warn(dev, "coreboot table entry too small!\n"); + return -EINVAL; + } + + device = kzalloc(sizeof(device->dev) + entry->size, GFP_KERNEL); if (!device) return -ENOMEM; @@ -101,7 +106,7 @@ static int coreboot_table_populate(struct device *dev, void *ptr) device->dev.parent = dev; device->dev.bus = &coreboot_bus_type; device->dev.release = coreboot_device_release; - memcpy(&device->entry, ptr_entry, entry->size); + memcpy(device->raw, ptr_entry, entry->size); ret = device_register(&device->dev); if (ret) { diff --git a/drivers/firmware/google/coreboot_table.h b/drivers/firmware/google/coreboot_table.h index beb778674acd..4a89277b99a3 100644 --- a/drivers/firmware/google/coreboot_table.h +++ b/drivers/firmware/google/coreboot_table.h @@ -66,6 +66,7 @@ struct coreboot_device { struct coreboot_table_entry entry; struct lb_cbmem_ref cbmem_ref; struct lb_framebuffer framebuffer; + DECLARE_FLEX_ARRAY(u8, raw); }; }; -- 2.35.1