From patchwork Fri Feb 28 12:14:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 206506 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 30BCDC3F2D3 for ; Fri, 28 Feb 2020 12:14:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F37132087F for ; Fri, 28 Feb 2020 12:14:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582892073; bh=yTXR/aWTRf31QuLVSWpsZDTg2cGIQ6ZDOSL3SMzock8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=xa9UTONoQ8QmqWOojVQORxByHh+jV826Dpz0vADglT6JV9Yo8YmyB3nkYFvqFRcUf zDk0TtBCrhZI3e4tHrOEYQ8gqTyw7FDI275aIqS9k0HWOs1mGcnaDFD66+sBXB9F76 PzgMUdnG3yEiIYzIBh1EyGibHmv+5cTo+2QHZJE8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726867AbgB1MO3 (ORCPT ); Fri, 28 Feb 2020 07:14:29 -0500 Received: from mail.kernel.org ([198.145.29.99]:45526 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725802AbgB1MO1 (ORCPT ); Fri, 28 Feb 2020 07:14:27 -0500 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 5EB2A246B0; Fri, 28 Feb 2020 12:14:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582892067; bh=yTXR/aWTRf31QuLVSWpsZDTg2cGIQ6ZDOSL3SMzock8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=w07DWlvLoPCwL0fRxHx/IgzLfCPPIjb58njjlVnP5imFJV5GIi/s5SG2dtLxv+4Ia EAvM20IQCwbRDgKgIFLFJ7/BXJwGZ3n0ZUbIbHbTUA6tgzDMXZMUoYS3ONFUW9RLWg w/5pAX4gy8MS1RYnbpZY6CNt6dvRQ9R5aMoCSng8= From: Ard Biesheuvel To: linux-efi@vger.kernel.org, Ingo Molnar , Thomas Gleixner Cc: Ard Biesheuvel , linux-kernel@vger.kernel.org, David Hildenbrand , Heinrich Schuchardt , Tom Lendacky Subject: [PATCH 6/6] efi: mark all EFI runtime services as unsupported on non-EFI boot Date: Fri, 28 Feb 2020 13:14:08 +0100 Message-Id: <20200228121408.9075-7-ardb@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200228121408.9075-1-ardb@kernel.org> References: <20200228121408.9075-1-ardb@kernel.org> Sender: linux-efi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-efi@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 41269a95ff85..d1746a579c99 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -300,12 +300,12 @@ 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