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 66FBAC433EF for ; Wed, 1 Dec 2021 13:32:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349512AbhLANfk (ORCPT ); Wed, 1 Dec 2021 08:35:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60288 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349463AbhLANfk (ORCPT ); Wed, 1 Dec 2021 08:35:40 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A610EC061574; Wed, 1 Dec 2021 05:32:19 -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 ams.source.kernel.org (Postfix) with ESMTPS id 6DD76B81EE2; Wed, 1 Dec 2021 13:32:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3036AC53FCD; Wed, 1 Dec 2021 13:32:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1638365537; bh=IjPToeYOH6L/JHRMA5azJJ2/4WG6GqgvrsNjOEzc+FE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jZQOUpAY4+3G29SCPheWO/jpzdSEJLQ79z+KR9U4Fd+AKCp+KgyfHcLIwQF6DFdnb p0UZT8mVz6aV/++acDdfzvZ3A0ZhKewiVMwyg1MtHFjI5sQxAakcxSZXtgcXqoEeal 1OF8bZxvJWi1LzYM/702UAu5Gw40DhsEz40c/ODFYvfkgfnYxUUmX5t9FWxgXwZmRY ArmAB3dwnX65psfobyiCcAHLG4Fg7xdgkSeKo8p9t1Q8JDJmLZ50OYUvT1N6sgPZq/ 0YQxSEmvsQfKgOa7SApobJTFZpsc3sD4PoyfrcdNrwwpq4BGkvHf5GbCL+u59ZSzdz qdKtBDnX0fLIg== Received: from johan by xi.lan with local (Exim 4.94.2) (envelope-from ) id 1msPiI-0007s0-1c; Wed, 01 Dec 2021 14:31:58 +0100 From: Johan Hovold To: Gabriel Somlo , "Michael S. Tsirkin" Cc: Greg Kroah-Hartman , Kees Cook , qemu-devel@nongnu.org, linux-kernel@vger.kernel.org, Johan Hovold , stable@vger.kernel.org Subject: [PATCH 3/4] firmware: qemu_fw_cfg: fix sysfs information leak Date: Wed, 1 Dec 2021 14:25:27 +0100 Message-Id: <20211201132528.30025-4-johan@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20211201132528.30025-1-johan@kernel.org> References: <20211201132528.30025-1-johan@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org Make sure to always NUL-terminate file names retrieved from the firmware to avoid accessing data beyond the entry slab buffer and exposing it through sysfs in case the firmware data is corrupt. Fixes: 75f3e8e47f38 ("firmware: introduce sysfs driver for QEMU's fw_cfg device") Cc: stable@vger.kernel.org # 4.6 Cc: Gabriel Somlo Signed-off-by: Johan Hovold --- drivers/firmware/qemu_fw_cfg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/firmware/qemu_fw_cfg.c b/drivers/firmware/qemu_fw_cfg.c index ccb7ed62452f..f08e056ed0ae 100644 --- a/drivers/firmware/qemu_fw_cfg.c +++ b/drivers/firmware/qemu_fw_cfg.c @@ -598,7 +598,7 @@ static int fw_cfg_register_file(const struct fw_cfg_file *f) /* set file entry information */ entry->size = be32_to_cpu(f->size); entry->select = be16_to_cpu(f->select); - memcpy(entry->name, f->name, FW_CFG_MAX_FILE_PATH); + strscpy(entry->name, f->name, FW_CFG_MAX_FILE_PATH); /* register entry under "/sys/firmware/qemu_fw_cfg/by_key/" */ err = kobject_init_and_add(&entry->kobj, &fw_cfg_sysfs_entry_ktype, -- 2.32.0