Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932585Ab2HIMyg (ORCPT ); Thu, 9 Aug 2012 08:54:36 -0400 Received: from mailhub.sw.ru ([195.214.232.25]:11756 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932262Ab2HIMyf (ORCPT ); Thu, 9 Aug 2012 08:54:35 -0400 Subject: [PATCH] tun: don't zeroize sock->file on detach To: davem@davemloft.net From: Stanislav Kinsbursky Cc: dhowells@redhat.com, netdev@vger.kernel.org, rick.jones2@hp.com, ycheng@google.com, linux-kernel@vger.kernel.org Date: Thu, 09 Aug 2012 16:50:40 +0400 Message-ID: <20120809124436.5156.26944.stgit@localhost.localdomain> User-Agent: StGit/0.16 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1549 Lines: 44 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. Cc: stable@vger.kernel.org Reported-by: Ruan Zhijie Tested-by: Ruan Zhijie Acked-by: Al Viro Acked-by: Eric Dumazet Acked-by: Yuchung Cheng Signed-off-by: Stanislav Kinsbursky --- drivers/net/tun.c | 1 - 1 files changed, 0 insertions(+), 1 deletions(-) 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 */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/