From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161413Ab2GLRNO (ORCPT ); Thu, 12 Jul 2012 13:13:14 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34494 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161398Ab2GLRNL (ORCPT ); Thu, 12 Jul 2012 13:13:11 -0400 Date: Thu, 12 Jul 2012 19:10:20 +0200 From: Oleg Nesterov To: Ingo Molnar , Peter Zijlstra , Srikar Dronamraju Cc: Ananth N Mavinakayanahalli , Anton Arapov , Hugh Dickins , linux-kernel@vger.kernel.org Subject: [PATCH 2/4] uprobes: fix register_for_each_vma()->vma_address() check Message-ID: <20120712171020.GA25500@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120712170934.GA25455@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 1. register_for_each_vma() checks that vma_address() == vaddr but this is not enough. We should also ensure that vaddr >= vm_start, find_vma() guarantees "vaddr < vm_end" only. 2. After the prevous changes, register_for_each_vma() is the only reason why vma_address() has to return loff_t, all other users know that we have the valid mapping at this offset and thus the overflow is not possible. Change the code to use vaddr_to_offset() instead, imho this looks more clean/understandable and now we can change vma_address(). 3. While at it, remove the unnecessary type-cast. Signed-off-by: Oleg Nesterov --- kernel/events/uprobes.c | 9 +++++---- 1 files changed, 5 insertions(+), 4 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 5c87042..734e199 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -823,12 +823,13 @@ static int register_for_each_vma(struct uprobe *uprobe, bool is_register) goto free; down_write(&mm->mmap_sem); - vma = find_vma(mm, (unsigned long)info->vaddr); - if (!vma || !valid_vma(vma, is_register)) + vma = find_vma(mm, info->vaddr); + if (!vma || !valid_vma(vma, is_register) || + vma->vm_file->f_mapping->host != uprobe->inode) goto unlock; - if (vma->vm_file->f_mapping->host != uprobe->inode || - vma_address(vma, uprobe->offset) != info->vaddr) + if (vma->vm_start > info->vaddr || + vaddr_to_offset(vma, info->vaddr) != uprobe->offset) goto unlock; if (is_register) { -- 1.5.5.1