From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754619AbZG1Px2 (ORCPT ); Tue, 28 Jul 2009 11:53:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754554AbZG1Px1 (ORCPT ); Tue, 28 Jul 2009 11:53:27 -0400 Received: from mgw1.diku.dk ([130.225.96.91]:54744 "EHLO mgw1.diku.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753991AbZG1Px0 (ORCPT ); Tue, 28 Jul 2009 11:53:26 -0400 Date: Tue, 28 Jul 2009 17:53:24 +0200 (CEST) From: Julia Lawall To: avi@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: [PATCH 3/9] virt/kvm: correct error-handling code Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Julia Lawall This code is not executed before file has been initialized to the result of calling eventfd_fget. This function returns an ERR_PTR value in an error case instead of NULL. Thus the test that file is not NULL is always true. A simplified version of the semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // @match exists@ expression x, E; statement S1, S2; @@ x = eventfd_fget(...) ... when != x = E ( * if (x == NULL || ...) S1 else S2 | * if (x == NULL && ...) S1 else S2 ) // Signed-off-by: Julia Lawall --- virt/kvm/eventfd.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c index 99017e8..bb4ebd8 100644 --- a/virt/kvm/eventfd.c +++ b/virt/kvm/eventfd.c @@ -230,7 +230,7 @@ fail: if (eventfd && !IS_ERR(eventfd)) eventfd_ctx_put(eventfd); - if (file && !IS_ERR(file)) + if (!IS_ERR(file)) fput(file); kfree(irqfd);