From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966266AbcIHJve (ORCPT ); Thu, 8 Sep 2016 05:51:34 -0400 Received: from terminus.zytor.com ([198.137.202.10]:39998 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758734AbcIHJv2 (ORCPT ); Thu, 8 Sep 2016 05:51:28 -0400 Date: Thu, 8 Sep 2016 02:50:27 -0700 From: tip-bot for Wei Yang Message-ID: Cc: peterz@infradead.org, hpa@zytor.com, tglx@linutronix.de, keescook@chromium.org, mingo@kernel.org, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, dvlasenk@redhat.com, richard.weiyang@gmail.com, jpoimboe@redhat.com, bp@alien8.de, brgerst@gmail.com, luto@kernel.org Reply-To: linux-kernel@vger.kernel.org, richard.weiyang@gmail.com, dvlasenk@redhat.com, bp@alien8.de, jpoimboe@redhat.com, luto@kernel.org, brgerst@gmail.com, hpa@zytor.com, peterz@infradead.org, keescook@chromium.org, tglx@linutronix.de, torvalds@linux-foundation.org, mingo@kernel.org In-Reply-To: <1471657213-31817-1-git-send-email-richard.weiyang@gmail.com> References: <1471657213-31817-1-git-send-email-richard.weiyang@gmail.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/boot] x86/e820: Fix very large 'size' handling boundary condition Git-Commit-ID: 3ec979658e5cc0fab86a42af79a650299e4d7135 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 3ec979658e5cc0fab86a42af79a650299e4d7135 Gitweb: http://git.kernel.org/tip/3ec979658e5cc0fab86a42af79a650299e4d7135 Author: Wei Yang AuthorDate: Sat, 20 Aug 2016 01:40:13 +0000 Committer: Ingo Molnar CommitDate: Thu, 8 Sep 2016 09:11:14 +0200 x86/e820: Fix very large 'size' handling boundary condition The (start, size) tuple represents a range [start, start + size - 1], which means "start" and "start + size - 1" should be compared to see whether the range overflows. For example, a range with (start, size): (0xffffffff fffffff0, 0x00000000 00000010) represents [0xffffffff fffffff0, 0xffffffff ffffffff] ... would be judged overflow in the original code, while actually it is not. This patch fixes this and makes sure it still works when size is zero. Signed-off-by: Wei Yang Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Kees Cook Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: yinghai@kernel.org Link: http://lkml.kernel.org/r/1471657213-31817-1-git-send-email-richard.weiyang@gmail.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/e820.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index 621b501..871f186 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -388,11 +388,11 @@ static int __init __append_e820_map(struct e820entry *biosmap, int nr_map) while (nr_map) { u64 start = biosmap->addr; u64 size = biosmap->size; - u64 end = start + size; + u64 end = start + size - 1; u32 type = biosmap->type; /* Overflow in 64 bits? Ignore the memory map. */ - if (start > end) + if (start > end && likely(size)) return -1; e820_add_region(start, size, type);