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 0BE5AC433F5 for ; Wed, 1 Dec 2021 13:32:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349536AbhLANfm (ORCPT ); Wed, 1 Dec 2021 08:35:42 -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: linux-kernel@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 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C29CFC433EF for ; Wed, 1 Dec 2021 13:39:55 +0000 (UTC) Received: from localhost ([::1]:39546 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1msPpy-0001Uo-RS for qemu-devel@archiver.kernel.org; Wed, 01 Dec 2021 08:39:54 -0500 Received: from eggs.gnu.org ([209.51.188.92]:43032) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1msPiz-0001zz-S3 for qemu-devel@nongnu.org; Wed, 01 Dec 2021 08:32:41 -0500 Received: from sin.source.kernel.org ([145.40.73.55]:41386) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1msPik-0003b3-CO for qemu-devel@nongnu.org; Wed, 01 Dec 2021 08:32:40 -0500 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 sin.source.kernel.org (Postfix) with ESMTPS id 01E89CE1D28; Wed, 1 Dec 2021 13:32:19 +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" 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 Received-SPF: pass client-ip=145.40.73.55; envelope-from=johan@kernel.org; helo=sin.source.kernel.org X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.716, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kees Cook , qemu-devel@nongnu.org, Greg Kroah-Hartman , Johan Hovold , stable@vger.kernel.org, linux-kernel@vger.kernel.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" 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