Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756180AbaJCVo4 (ORCPT ); Fri, 3 Oct 2014 17:44:56 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:45353 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756062AbaJCVnY (ORCPT ); Fri, 3 Oct 2014 17:43:24 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kees Cook , Baoquan He , Vivek Goyal , "Rafael J. Wysocki" , Wei Yongjun , Pavel Machek , Linus Torvalds , Ingo Molnar Subject: [PATCH 3.16 216/357] x86/kaslr: Avoid the setup_data area when picking location Date: Fri, 3 Oct 2014 14:30:02 -0700 Message-Id: <20141003212940.013998664@linuxfoundation.org> X-Mailer: git-send-email 2.1.2 In-Reply-To: <20141003212933.458851516@linuxfoundation.org> References: <20141003212933.458851516@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kees Cook commit 0cacbfbeb5077b63d5d3cf6df88b14ac12ad584b upstream. The KASLR location-choosing logic needs to avoid the setup_data list memory areas as well. Without this, it would be possible to have the ASLR position stomp on the memory, ultimately causing the boot to fail. Signed-off-by: Kees Cook Tested-by: Baoquan He Cc: Vivek Goyal Cc: Rafael J. Wysocki Cc: Wei Yongjun Cc: Pavel Machek Cc: Linus Torvalds Link: http://lkml.kernel.org/r/20140911161931.GA12001@www.outflux.net Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/boot/compressed/aslr.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) --- a/arch/x86/boot/compressed/aslr.c +++ b/arch/x86/boot/compressed/aslr.c @@ -183,12 +183,27 @@ static void mem_avoid_init(unsigned long static bool mem_avoid_overlap(struct mem_vector *img) { int i; + struct setup_data *ptr; for (i = 0; i < MEM_AVOID_MAX; i++) { if (mem_overlaps(img, &mem_avoid[i])) return true; } + /* Avoid all entries in the setup_data linked list. */ + ptr = (struct setup_data *)(unsigned long)real_mode->hdr.setup_data; + while (ptr) { + struct mem_vector avoid; + + avoid.start = (u64)ptr; + avoid.size = sizeof(*ptr) + ptr->len; + + if (mem_overlaps(img, &avoid)) + return true; + + ptr = (struct setup_data *)(unsigned long)ptr->next; + } + return false; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/