From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757568Ab3KHP4N (ORCPT ); Fri, 8 Nov 2013 10:56:13 -0500 Received: from mx1.redhat.com ([209.132.183.28]:64401 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756024Ab3KHP4L (ORCPT ); Fri, 8 Nov 2013 10:56:11 -0500 Date: Fri, 8 Nov 2013 16:57:35 +0100 From: Oleg Nesterov To: Ingo Molnar Cc: Anton Arapov , David Smith , "Frank Ch. Eigler" , Srikar Dronamraju , linux-kernel@vger.kernel.org Subject: [PATCH 1/1] uprobes: Fix the wrong usage of current->utask in uprobe_copy_process() Message-ID: <20131108155735.GB26611@redhat.com> References: <20131108155714.GA26611@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131108155714.GA26611@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit aa59c53fd459 "uprobes: Change uprobe_copy_process() to dup xol_area" has a stupid typo, we need to setup t->utask->vaddr but the code wrongly uses current->utask. Even with this bug dup_xol_work() works "in practice", but only because get_unmapped_area(NULL, TASK_SIZE - PAGE_SIZE) likely returns the same address every time. Signed-off-by: Oleg Nesterov --- kernel/events/uprobes.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 26fdd65..847201f 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1446,7 +1446,7 @@ void uprobe_copy_process(struct task_struct *t, unsigned long flags) if (!work) return uprobe_warn(t, "dup xol area"); - utask->vaddr = area->vaddr; + t->utask->vaddr = area->vaddr; init_task_work(work, dup_xol_work); task_work_add(t, work, true); } -- 1.5.5.1