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=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 92F29C43381 for ; Wed, 27 Mar 2019 18:22:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6518F21738 for ; Wed, 27 Mar 2019 18:22:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553710955; bh=81JqgWMFB869y/ri47/4vbTXKaXsKq3lhQfG4oVPJcg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=lbDY2oGP0NR3UXBusGtaM21HVoPCh/qNnqIS/OTOUzsRspwIGAel3b8jXiY4ePXcz orGO+NP8oUyqTzVEYc1RuJ3a25q0RH4vgMynyEbwYFbyLWxXsYcuSQlcKhodnbiLIE 9Y97+xE7GwB0E7/204w3YSuEtGtxSHz5jMQiGjD0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391031AbfC0SWe (ORCPT ); Wed, 27 Mar 2019 14:22:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:40700 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390573AbfC0SWd (ORCPT ); Wed, 27 Mar 2019 14:22:33 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (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 8EEBF2147C; Wed, 27 Mar 2019 18:22:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553710952; bh=81JqgWMFB869y/ri47/4vbTXKaXsKq3lhQfG4oVPJcg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0dAZ6V8jWYnGH/ZX6z9mDJxPhrViVBiOPDYT5mxDY6j0BhfmB/EF4PK2WsANqYqzB gL9gl5EKLZTd/l123VjpT0+DFt+KHCMnGc2veya1JQHdVraorfVIUHNhREk839sVRM 7KgLgLFFS5iMB3FQx1qwEOzG3N3VP87z8tG2VvSk= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ard Biesheuvel , AKASHI Takahiro , Alexander Graf , Bjorn Andersson , Borislav Petkov , Heinrich Schuchardt , Jeffrey Hugo , Lee Jones , Leif Lindholm , Linus Torvalds , Matt Fleming , Peter Jones , Peter Zijlstra , Thomas Gleixner , linux-efi@vger.kernel.org, Ingo Molnar , Sasha Levin Subject: [PATCH AUTOSEL 4.9 62/87] efi/memattr: Don't bail on zero VA if it equals the region's PA Date: Wed, 27 Mar 2019 14:20:15 -0400 Message-Id: <20190327182040.17444-62-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190327182040.17444-1-sashal@kernel.org> References: <20190327182040.17444-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Ard Biesheuvel [ Upstream commit 5de0fef0230f3c8d75cff450a71740a7bf2db866 ] The EFI memory attributes code cross-references the EFI memory map with the more granular EFI memory attributes table to ensure that they are in sync before applying the strict permissions to the regions it describes. Since we always install virtual mappings for the EFI runtime regions to which these strict permissions apply, we currently perform a sanity check on the EFI memory descriptor, and ensure that the EFI_MEMORY_RUNTIME bit is set, and that the virtual address has been assigned. However, in cases where a runtime region exists at physical address 0x0, and the virtual mapping equals the physical mapping, e.g., when running in mixed mode on x86, we encounter a memory descriptor with the runtime attribute and virtual address 0x0, and incorrectly draw the conclusion that a runtime region exists for which no virtual mapping was installed, and give up altogether. The consequence of this is that firmware mappings retain their read-write-execute permissions, making the system more vulnerable to attacks. So let's only bail if the virtual address of 0x0 has been assigned to a physical region that does not reside at address 0x0. Signed-off-by: Ard Biesheuvel Acked-by: Sai Praneeth Prakhya Cc: AKASHI Takahiro Cc: Alexander Graf Cc: Bjorn Andersson Cc: Borislav Petkov Cc: Heinrich Schuchardt Cc: Jeffrey Hugo Cc: Lee Jones Cc: Leif Lindholm Cc: Linus Torvalds Cc: Matt Fleming Cc: Peter Jones Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Fixes: 10f0d2f577053 ("efi: Implement generic support for the Memory ...") Link: http://lkml.kernel.org/r/20190202094119.13230-4-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin --- drivers/firmware/efi/memattr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/firmware/efi/memattr.c b/drivers/firmware/efi/memattr.c index 236004b9a50d..9faa09e7c31f 100644 --- a/drivers/firmware/efi/memattr.c +++ b/drivers/firmware/efi/memattr.c @@ -93,7 +93,7 @@ static bool entry_is_valid(const efi_memory_desc_t *in, efi_memory_desc_t *out) if (!(md->attribute & EFI_MEMORY_RUNTIME)) continue; - if (md->virt_addr == 0) { + if (md->virt_addr == 0 && md->phys_addr != 0) { /* no virtual mapping has been installed by the stub */ break; } -- 2.19.1