From patchwork Wed May 16 12:39:33 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Wang X-Patchwork-Id: 914596 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 40mDXl63pxz9s2R for ; Wed, 16 May 2018 22:39:51 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752482AbeEPMjl (ORCPT ); Wed, 16 May 2018 08:39:41 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:35610 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752205AbeEPMjj (ORCPT ); Wed, 16 May 2018 08:39:39 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 3233C81663C4; Wed, 16 May 2018 12:39:39 +0000 (UTC) Received: from jason-ThinkPad-T450s.redhat.com (ovpn-12-64.pek2.redhat.com [10.72.12.64]) by smtp.corp.redhat.com (Postfix) with ESMTP id DB6772166BAD; Wed, 16 May 2018 12:39:35 +0000 (UTC) From: Jason Wang To: netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: xiyou.wangcong@gmail.com, avagin@virtuozzo.com, mst@redhat.com, Jason Wang Subject: [PATCH net] tuntap: fix use after free during release Date: Wed, 16 May 2018 20:39:33 +0800 Message-Id: <1526474373-16685-1-git-send-email-jasowang@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Wed, 16 May 2018 12:39:39 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Wed, 16 May 2018 12:39:39 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'jasowang@redhat.com' RCPT:'' Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org After commit b196d88aba8a ("tun: fix use after free for ptr_ring") we need clean up tx ring during release(). But unfortunately, it tries to do the cleanup blindly after socket were destroyed which will lead another use-after-free. Fix this by doing the cleanup before dropping the last reference of the socket in __tun_detach(). Reported-by: Andrei Vagin Acked-by: Andrei Vagin Fixes: b196d88aba8a ("tun: fix use after free for ptr_ring") Signed-off-by: Jason Wang --- drivers/net/tun.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 9fbbb32..d45ac37 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -729,6 +729,7 @@ static void __tun_detach(struct tun_file *tfile, bool clean) } if (tun) xdp_rxq_info_unreg(&tfile->xdp_rxq); + ptr_ring_cleanup(&tfile->tx_ring, tun_ptr_free); sock_put(&tfile->sk); } } @@ -3245,7 +3246,6 @@ static int tun_chr_close(struct inode *inode, struct file *file) struct tun_file *tfile = file->private_data; tun_detach(tfile, true); - ptr_ring_cleanup(&tfile->tx_ring, tun_ptr_free); return 0; }