From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753837AbbGAXEh (ORCPT ); Wed, 1 Jul 2015 19:04:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41358 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752407AbbGAXE1 (ORCPT ); Wed, 1 Jul 2015 19:04:27 -0400 Date: Thu, 2 Jul 2015 01:03:02 +0200 From: Oleg Nesterov To: Andrew Morton Cc: Benjamin LaHaise , David Rientjes , Hugh Dickins , Jeff Moyer , Kirill Shutemov , Pavel Emelyanov , linux-kernel@vger.kernel.org Subject: [PATCH v2 1/5] mremap: don't leak new_vma if f_op->mremap() fails Message-ID: <20150701230302.GA18021@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150701230244.GA18003@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 move_vma() can't just return if f_op->mremap() fails, we should unmap the new vma like we do if move_page_tables() fails. To avoid the code duplication this patch moves the "move entries back" under the new "if (err)" branch. Signed-off-by: Oleg Nesterov Acked-by: David Rientjes --- mm/mremap.c | 16 +++++++--------- 1 files changed, 7 insertions(+), 9 deletions(-) diff --git a/mm/mremap.c b/mm/mremap.c index a7c93ec..f54a43f 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -276,6 +276,12 @@ static unsigned long move_vma(struct vm_area_struct *vma, moved_len = move_page_tables(vma, old_addr, new_vma, new_addr, old_len, need_rmap_locks); if (moved_len < old_len) { + err = -ENOMEM; + } else if (vma->vm_file && vma->vm_file->f_op->mremap) { + err = vma->vm_file->f_op->mremap(vma->vm_file, new_vma); + } + + if (unlikely(err)) { /* * On error, move entries back from new area to old, * which will succeed since page tables still there, @@ -286,16 +292,8 @@ static unsigned long move_vma(struct vm_area_struct *vma, vma = new_vma; old_len = new_len; old_addr = new_addr; - new_addr = -ENOMEM; + new_addr = err; } else { - if (vma->vm_file && vma->vm_file->f_op->mremap) { - err = vma->vm_file->f_op->mremap(vma->vm_file, new_vma); - if (err < 0) { - move_page_tables(new_vma, new_addr, vma, - old_addr, moved_len, true); - return err; - } - } arch_remap(mm, old_addr, old_addr + old_len, new_addr, new_addr + new_len); } -- 1.5.5.1