From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755390AbZLHOEQ (ORCPT ); Tue, 8 Dec 2009 09:04:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755304AbZLHOEP (ORCPT ); Tue, 8 Dec 2009 09:04:15 -0500 Received: from hera.kernel.org ([140.211.167.34]:54548 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755280AbZLHOEO (ORCPT ); Tue, 8 Dec 2009 09:04:14 -0500 Date: Tue, 8 Dec 2009 14:03:32 GMT From: tip-bot for Andi Kleen Cc: linux-kernel@vger.kernel.org, dvhltc@us.ibm.com, akpm@linuxfoundation.org, hpa@zytor.com, mingo@redhat.com, andi@firstfloor.org, peterz@infradead.org, npiggin@suse.de, ak@linux.intel.com, tglx@linutronix.de Reply-To: mingo@redhat.com, hpa@zytor.com, akpm@linuxfoundation.org, dvhltc@us.ibm.com, linux-kernel@vger.kernel.org, andi@firstfloor.org, peterz@infradead.org, npiggin@suse.de, ak@linux.intel.com, tglx@linutronix.de In-Reply-To: <20091208121942.GA21298@basil.fritz.box> References: <20091208121942.GA21298@basil.fritz.box> To: linux-tip-commits@vger.kernel.org Subject: [tip:core/urgent] futex: Take mmap_sem for get_user_pages in fault_in_user_writeable Message-ID: Git-Commit-ID: 722d0172377a5697919b9f7e5beb95165b1dec4e X-Mailer: tip-git-log-daemon MIME-Version: 1.0 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: 722d0172377a5697919b9f7e5beb95165b1dec4e Gitweb: http://git.kernel.org/tip/722d0172377a5697919b9f7e5beb95165b1dec4e Author: Andi Kleen AuthorDate: Tue, 8 Dec 2009 13:19:42 +0100 Committer: Thomas Gleixner CommitDate: Tue, 8 Dec 2009 14:59:36 +0100 futex: Take mmap_sem for get_user_pages in fault_in_user_writeable get_user_pages() must be called with mmap_sem held. Signed-off-by: Andi Kleen Cc: stable@kernel.org Cc: Andrew Morton Cc: Nick Piggin Cc: Darren Hart Cc: Peter Zijlstra LKML-Reference: <20091208121942.GA21298@basil.fritz.box> Signed-off-by: Thomas Gleixner --- kernel/futex.c | 10 ++++++++-- 1 files changed, 8 insertions(+), 2 deletions(-) diff --git a/kernel/futex.c b/kernel/futex.c index fb65e82..d73ef1f 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -304,8 +304,14 @@ void put_futex_key(int fshared, union futex_key *key) */ static int fault_in_user_writeable(u32 __user *uaddr) { - int ret = get_user_pages(current, current->mm, (unsigned long)uaddr, - 1, 1, 0, NULL, NULL); + struct mm_struct *mm = current->mm; + int ret; + + down_read(&mm->mmap_sem); + ret = get_user_pages(current, mm, (unsigned long)uaddr, + 1, 1, 0, NULL, NULL); + up_read(&mm->mmap_sem); + return ret < 0 ? ret : 0; }