From patchwork Wed Jul 11 11:48:20 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislav Kinsbursky X-Patchwork-Id: 170440 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 [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 0ACDD2C01D3 for ; Wed, 11 Jul 2012 21:49:13 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757339Ab2GKLsx (ORCPT ); Wed, 11 Jul 2012 07:48:53 -0400 Received: from mailhub.sw.ru ([195.214.232.25]:48154 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753554Ab2GKLsw (ORCPT ); Wed, 11 Jul 2012 07:48:52 -0400 Received: from localhost6.localdomain6 ([10.30.20.35]) by relay.sw.ru (8.13.4/8.13.4) with ESMTP id q6BBmYPQ024771; Wed, 11 Jul 2012 15:48:35 +0400 (MSK) Subject: [RFC PATCH] tun: don't zeroize sock->file on detach To: davem@davemloft.net From: Stanislav Kinsbursky Cc: netdev@vger.kernel.org, ruanzhijie@hotmail.com, linux-kernel@vger.kernel.org Date: Wed, 11 Jul 2012 15:48:20 +0400 Message-ID: <20120711114753.24395.53193.stgit@localhost6.localdomain6> User-Agent: StGit/0.15 MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This is a fix for bug, introduced in 3.4 kernel by commit 1ab5ecb90cb6a3df1476e052f76a6e8f6511cb3d, which, among other things, replaced simple sock_put() by sk_release_kernel(). Below is sequence, which leads to oops for non-persistent devices: tun_chr_close() tun_detach() <== tun->socket.file = NULL tun_free_netdev() sk_release_sock() sock_release(sock->file == NULL) iput(SOCK_INODE(sock)) <== dereference on NULL pointer This patch just removes zeroing of socket's file from __tun_detach(). sock_release() will do this. Signed-off-by: Stanislav Kinsbursky Acked-by: Eric Dumazet Acked-by: Yuchung Cheng --- drivers/net/tun.c | 1 - 1 files changed, 0 insertions(+), 1 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 987aeef..c1639f3 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -185,7 +185,6 @@ static void __tun_detach(struct tun_struct *tun) netif_tx_lock_bh(tun->dev); netif_carrier_off(tun->dev); tun->tfile = NULL; - tun->socket.file = NULL; netif_tx_unlock_bh(tun->dev); /* Drop read queue */