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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 28E60C2BB8A for ; Sun, 8 Mar 2020 08:09:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 02AA52146E for ; Sun, 8 Mar 2020 08:09:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583654972; bh=m6+HzzP8EIGLHVP73RWu+8Lj4q7KWGfvDJgTN6bylFs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=jr2kZpOW3E3eyhRM7Yu92RiS94Hh0hT7lp6wDv7NF/VAjhCXURGvfZc8ULkoatOxL jcipcMHcWmfUrwvaC0RLWIpHLiX5rhgppcs2nCFjBQQoNpIsDwDTUeOG7zDX+LmD6/ BgGjoN/+5ngm9jZTNduG4rv6AFwg1vArZNbiJJTs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726427AbgCHIJa (ORCPT ); Sun, 8 Mar 2020 04:09:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:36638 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725854AbgCHIJ1 (ORCPT ); Sun, 8 Mar 2020 04:09:27 -0400 Received: from e123331-lin.home (amontpellier-657-1-18-247.w109-210.abo.wanadoo.fr [109.210.65.247]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8267D2072A; Sun, 8 Mar 2020 08:09:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583654967; bh=m6+HzzP8EIGLHVP73RWu+8Lj4q7KWGfvDJgTN6bylFs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QU3TTxxN+yfK3Zm8Yc4NUQStEXcBTx9v8Xdvt3/7Cvl1o1HQ79NsJacPiZi25DdxE glHNxoroVMSQtXFWfw2TxQ0Ob0oSTKcOondgwTz2cJjniifwvhX89ltoiqSKc6Tf0t jgKN8PhWDiw9xev7g+LFExlkOWwQIgBEM2I8FvZc= From: Ard Biesheuvel To: linux-efi@vger.kernel.org, Ingo Molnar , Thomas Gleixner Cc: Ard Biesheuvel , linux-kernel@vger.kernel.org, Arvind Sankar , Christoph Hellwig , David Hildenbrand , Davidlohr Bueso , Guenter Roeck , Heinrich Schuchardt , Jonathan Corbet , Lukas Bulwahn , Masahiro Yamada , Nikolai Merinov , Tom Lendacky , Vladis Dronov Subject: [PATCH 06/28] efi: mark all EFI runtime services as unsupported on non-EFI boot Date: Sun, 8 Mar 2020 09:08:37 +0100 Message-Id: <20200308080859.21568-7-ardb@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200308080859.21568-1-ardb@kernel.org> References: <20200308080859.21568-1-ardb@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Recent changes to the way we deal with EFI runtime services that are marked as unsupported by the firmware resulted in a regression for non-EFI boot. The problem is that all EFI runtime services are marked as available by default, and any non-NULL checks on the EFI service function pointers (which will be non-NULL even for runtime services that are unsupported on an EFI boot) were replaced with checks against the mask stored in efi.runtime_supported_mask. When doing a non-EFI boot, this check against the mask will return a false positive, given the fact that all runtime services are marked as enabled by default. Since we dropped the non-NULL check of the runtime service function pointer in favor of the mask check, we will now unconditionally dereference the function pointer, even if it is NULL, and go boom. So let's ensure that the mask reflects reality on a non-EFI boot, which is that all EFI runtime services are unsupported. Reported-by: David Hildenbrand Signed-off-by: Ard Biesheuvel --- drivers/firmware/efi/efi.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 91f546dc13d4..1d5e9a030cb1 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -354,12 +354,12 @@ static int __init efisubsys_init(void) { int error; - if (!efi_enabled(EFI_BOOT)) - return 0; - if (!efi_enabled(EFI_RUNTIME_SERVICES)) efi.runtime_supported_mask = 0; + if (!efi_enabled(EFI_BOOT)) + return 0; + if (efi.runtime_supported_mask) { /* * Since we process only one efi_runtime_service() at a time, an -- 2.17.1