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 C91AFC433EF for ; Tue, 18 Jan 2022 16:13:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347615AbiARQNM (ORCPT ); Tue, 18 Jan 2022 11:13:12 -0500 Received: from sin.source.kernel.org ([145.40.73.55]:41456 "EHLO sin.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347200AbiARQLV (ORCPT ); Tue, 18 Jan 2022 11:11:21 -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 B1AF5CE1A30; Tue, 18 Jan 2022 16:11:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 99D54C00446; Tue, 18 Jan 2022 16:11:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1642522278; bh=9OtNLgBZCevG6a5ICRwisDy1q+BlBNTtwsIeLoU+79w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nRBvYsOHcE152IIfbn+xO7pGFso9PhH2z2ev71SMNCLiQ7iB7RsiGVZv5itPSsA9i aHDTc48Uk6KKvL3qFPUV8Safusn5P2mWGD0NBivNnwXgHwu7uHH0IDL0HoYRJX6yBB PW+QZcb5jjDedTOqnHhJ5qW313PWmC7cWdJPQBHs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Gabriel Somlo , Johan Hovold , "Michael S. Tsirkin" Subject: [PATCH 5.16 18/28] firmware: qemu_fw_cfg: fix sysfs information leak Date: Tue, 18 Jan 2022 17:06:13 +0100 Message-Id: <20220118160453.008663385@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220118160452.384322748@linuxfoundation.org> References: <20220118160452.384322748@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Johan Hovold commit 1b656e9aad7f4886ed466094d1dc5ee4dd900d20 upstream. 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 Link: https://lore.kernel.org/r/20211201132528.30025-4-johan@kernel.org Signed-off-by: Michael S. Tsirkin Signed-off-by: Greg Kroah-Hartman --- drivers/firmware/qemu_fw_cfg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/firmware/qemu_fw_cfg.c +++ b/drivers/firmware/qemu_fw_cfg.c @@ -601,7 +601,7 @@ static int fw_cfg_register_file(const st /* 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,