From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756470Ab1LERwm (ORCPT ); Mon, 5 Dec 2011 12:52:42 -0500 Received: from terminus.zytor.com ([198.137.202.10]:58881 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753601Ab1LERwl (ORCPT ); Mon, 5 Dec 2011 12:52:41 -0500 Date: Mon, 5 Dec 2011 09:52:17 -0800 From: tip-bot for Ludwig Nussel Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, torvalds@linux-foundation.org, akpm@linux-foundation.org, tglx@linutronix.de, ludwig.nussel@suse.de, harvey.harrison@gmail.com, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, tglx@linutronix.de, ludwig.nussel@suse.de, harvey.harrison@gmail.com, mingo@elte.hu In-Reply-To: <201111152246.pAFMklOB028527@wpaz5.hot.corp.google.com> References: <201111152246.pAFMklOB028527@wpaz5.hot.corp.google.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/mm] x86: Fix mmap random address range Git-Commit-ID: 9af0c7a6fa860698d080481f24a342ba74b68982 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.6 (terminus.zytor.com [127.0.0.1]); Mon, 05 Dec 2011 09:52:23 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 9af0c7a6fa860698d080481f24a342ba74b68982 Gitweb: http://git.kernel.org/tip/9af0c7a6fa860698d080481f24a342ba74b68982 Author: Ludwig Nussel AuthorDate: Tue, 15 Nov 2011 14:46:46 -0800 Committer: Ingo Molnar CommitDate: Mon, 5 Dec 2011 17:07:23 +0100 x86: Fix mmap random address range On x86_32 casting the unsigned int result of get_random_int() to long may result in a negative value. On x86_32 the range of mmap_rnd() therefore was -255 to 255. The 32bit mode on x86_64 used 0 to 255 as intended. The bug was introduced by 675a081 ("x86: unify mmap_{32|64}.c") in January 2008. Signed-off-by: Ludwig Nussel Cc: Linus Torvalds Cc: harvey.harrison@gmail.com Cc: "H. Peter Anvin" Cc: Harvey Harrison Signed-off-by: Andrew Morton Link: http://lkml.kernel.org/r/201111152246.pAFMklOB028527@wpaz5.hot.corp.google.com Signed-off-by: Ingo Molnar --- arch/x86/mm/mmap.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c index 4b5ba85..845df68 100644 --- a/arch/x86/mm/mmap.c +++ b/arch/x86/mm/mmap.c @@ -75,9 +75,9 @@ static unsigned long mmap_rnd(void) */ if (current->flags & PF_RANDOMIZE) { if (mmap_is_ia32()) - rnd = (long)get_random_int() % (1<<8); + rnd = get_random_int() % (1<<8); else - rnd = (long)(get_random_int() % (1<<28)); + rnd = get_random_int() % (1<<28); } return rnd << PAGE_SHIFT; }