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 X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F2B8CC31E5C for ; Mon, 17 Jun 2019 18:24:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CC0DD2084D for ; Mon, 17 Jun 2019 18:24:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="qQYXAZfu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726694AbfFQSYH (ORCPT ); Mon, 17 Jun 2019 14:24:07 -0400 Received: from mail-io1-f67.google.com ([209.85.166.67]:36824 "EHLO mail-io1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725764AbfFQSYH (ORCPT ); Mon, 17 Jun 2019 14:24:07 -0400 Received: by mail-io1-f67.google.com with SMTP id h6so23460950ioh.3; Mon, 17 Jun 2019 11:24:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=LNDj/9Uge4rb5LG4sl2oFwkMWYo5QYyd6vgWjHPxMYU=; b=qQYXAZfu49iyzDbgqn6cbHpgYcLoIDlv7zGX98wyqWvuIYcHIxug+f4sJAV0e8O4xS s2aspucn8QC8QewHtixUcfZtc37sAjg4Air9VWD8cmQdivRugh0avoZmTyk4tvKkEMM+ uCi9QqhFp1GzZUUoej5+j58BBKCszJrqE9LSTLHE3OQBav6nWg3gvpNEdf7ol3uwnMri Ha2g/qaKSkhHN+sklpgoeU6VM0qsdYBK1J0JAG/c0O5TAzucfcxvUH8rWNbS3nvxTQmi W45Q9UxajNij0sKKOqw9/RMl+1F/XFB7aUFZk/25qTaw1H1SumUXrt6TCVFXSbtgxEHf 7PyA== 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; bh=LNDj/9Uge4rb5LG4sl2oFwkMWYo5QYyd6vgWjHPxMYU=; b=MOomKdaZ4tlHnx2hA8hPuFwByQVapFn7Ii6TIOoSiZimsGehhTK+cHcsUQcm8t5FQV hQQuVqxQRVq08wEXY2MpJr2HrdBR9A61y5myHl00mIEIDlnXC2MAt8BjE0hHKdKCt3cM uosNvXFWKqu8ZHFnbgR5SSun3d07lidsv+f7451rI17a20Ur8lZ3tmBMbMYlxqwwuucb paTnHNCzgr8TvQaWU6wZgcsHCQd7Tuicb1+1c6qnAQZl1+hEeNMRP0enY2FwqQV2gZJA hkiAVJFPxYe6cD9TH2HnvWYL0wT3G68Ke661Z4KcMLfa4ANdURaeo/B0YKE/10JYBtiF Ohrw== X-Gm-Message-State: APjAAAX6967Y+DKCtqLGHZwchjy/t01KjCKM6Pw73E25GvNLAqx0IxZ/ BBVJonACh2IoEQGXV/DnUxA= X-Google-Smtp-Source: APXvYqzyjNQeJEGdeV6RSpDBxUhnrQBrAbJd9GIEz2zpA9IlQT9KOaNLnUdyRAooNwA/EyrALQpQGw== X-Received: by 2002:a5d:8e08:: with SMTP id e8mr42656031iod.139.1560795845930; Mon, 17 Jun 2019 11:24:05 -0700 (PDT) Received: from svens-asus.arcx.com ([184.94.50.30]) by smtp.gmail.com with ESMTPSA id r5sm13961804iom.42.2019.06.17.11.24.04 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Mon, 17 Jun 2019 11:24:05 -0700 (PDT) From: Sven Van Asbroeck X-Google-Original-From: Sven Van Asbroeck To: Luis Chamberlain Cc: Stable , Mimi Zohar , Kees Cook , Greg Kroah-Hartman , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org Subject: [PATCH] firmware: improve LSM/IMA security behaviour Date: Mon, 17 Jun 2019 14:23:54 -0400 Message-Id: <20190617182354.10846-1-TheSven73@gmail.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The firmware loader queries if LSM/IMA permits it to load firmware via the sysfs fallback. Unfortunately, the code does the opposite: it expressly permits sysfs fw loading if security_kernel_load_data( LOADING_FIRMWARE) returns -EACCES. This happens because a zero-on-success return value is cast to a bool that's true on success. Fix the return value handling so we get the correct behaviour. Fixes: 6e852651f28e ("firmware: add call to LSM hook before firmware sysfs fallback") Cc: Stable Cc: Mimi Zohar Cc: Kees Cook To: Luis Chamberlain Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: linux-kernel@vger.kernel.org Signed-off-by: Sven Van Asbroeck --- drivers/base/firmware_loader/fallback.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c index f962488546b6..103b5d37fa86 100644 --- a/drivers/base/firmware_loader/fallback.c +++ b/drivers/base/firmware_loader/fallback.c @@ -659,7 +659,7 @@ static bool fw_run_sysfs_fallback(enum fw_opt opt_flags) /* Also permit LSMs and IMA to fail firmware sysfs fallback */ ret = security_kernel_load_data(LOADING_FIRMWARE); if (ret < 0) - return ret; + return false; return fw_force_sysfs_fallback(opt_flags); } -- 2.17.1