From patchwork Thu Dec 18 10:20:46 2008 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wei Yongjun X-Patchwork-Id: 14642 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by ozlabs.org (Postfix) with ESMTP id 869DADDF1E for ; Thu, 18 Dec 2008 21:20:09 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751544AbYLRKUF (ORCPT ); Thu, 18 Dec 2008 05:20:05 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751470AbYLRKUE (ORCPT ); Thu, 18 Dec 2008 05:20:04 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:59824 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752128AbYLRKUD (ORCPT ); Thu, 18 Dec 2008 05:20:03 -0500 Received: from tang.cn.fujitsu.com (tang.cn.fujitsu.com [10.167.250.3]) by song.cn.fujitsu.com (Postfix) with ESMTP id 77093170116; Thu, 18 Dec 2008 18:23:45 +0800 (CST) Received: from fnst.cn.fujitsu.com (localhost.localdomain [127.0.0.1]) by tang.cn.fujitsu.com (8.13.1/8.13.1) with ESMTP id mBIANjAf024771; Thu, 18 Dec 2008 18:23:45 +0800 Received: from [10.167.141.76] (unknown [10.167.141.76]) by fnst.cn.fujitsu.com (Postfix) with ESMTP id CE70ED439B; Thu, 18 Dec 2008 18:25:19 +0800 (CST) Message-ID: <494A23FE.6020305@cn.fujitsu.com> Date: Thu, 18 Dec 2008 18:20:46 +0800 From: Wei Yongjun User-Agent: Thunderbird 2.0.0.6 (Windows/20070728) MIME-Version: 1.0 To: David Miller , netdev@vger.kernel.org Subject: [PATCH] net: Fix module refcount leak in kernel_accept() Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The kernel_accept() does not hold the module refcount of newsock->ops->owner, so we need __module_get(newsock->ops->owner) code after call kernel_accept() by hand. In sunrpc, the module refcount is missing to hold. So this cause kernel panic. Used following script to reproduct: while [ 1 ]; do mount -t nfs4 192.168.0.19:/ /mnt touch /mnt/file umount /mnt lsmod | grep ipv6 done This patch fixed the problem by add __module_get(newsock->ops->owner) to kernel_accept(). So we do not need to used __module_get(newsock->ops->owner) in every place when used kernel_accept(). Signed-off-by: Wei Yongjun --- net/bluetooth/rfcomm/core.c | 2 -- net/socket.c | 1 + 2 files changed, 1 insertions(+), 2 deletions(-) diff --git a/net/bluetooth/rfcomm/core.c b/net/bluetooth/rfcomm/core.c index ba537fa..ce68e04 100644 --- a/net/bluetooth/rfcomm/core.c +++ b/net/bluetooth/rfcomm/core.c @@ -1786,8 +1786,6 @@ static inline void rfcomm_accept_connection(struct rfcomm_session *s) if (err < 0) return; - __module_get(nsock->ops->owner); - /* Set our callbacks */ nsock->sk->sk_data_ready = rfcomm_l2data_ready; nsock->sk->sk_state_change = rfcomm_l2state_change; diff --git a/net/socket.c b/net/socket.c index 92764d8..76ba80a 100644 --- a/net/socket.c +++ b/net/socket.c @@ -2307,6 +2307,7 @@ int kernel_accept(struct socket *sock, struct socket **newsock, int flags) } (*newsock)->ops = sock->ops; + __module_get((*newsock)->ops->owner); done: return err;