From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3A9E7C33CB7 for ; Fri, 31 Jan 2020 06:57:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0BE6F20705 for ; Fri, 31 Jan 2020 06:57:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="RpxuJWwR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728105AbgAaG5P (ORCPT ); Fri, 31 Jan 2020 01:57:15 -0500 Received: from userp2130.oracle.com ([156.151.31.86]:43546 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726127AbgAaG5O (ORCPT ); Fri, 31 Jan 2020 01:57:14 -0500 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id 00V6sLVf081667; Fri, 31 Jan 2020 06:57:00 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : mime-version : content-type; s=corp-2019-08-05; bh=tiB4iq2Q8i2SRPr5AGcPm2GpvYmtOgewas625ubrIEk=; b=RpxuJWwR6mcIF3f/8LYbzt0xCyuxrP28iIObRiNxaPOIMhVCKgHq2PG9hQtarfeFrxWV oSGJ6UF+gwiav5ES1sQX6pGRnVWifn8ULUCeMgn/u5kylg91sKt7Ja3Qphx5ZkyXO5/H ch+7c/xODwYZgIYrce2fbpQ7325YylLQdcfm+QRIqar4DtMLDcEhZMMuGHFmG+U5vps2 0kI7PmEOoNDHRAJy//guCcoSSQWwxisPtnNP64OjylUgJC0LU4t2NhUlziVqErZsCfxP 7eNQUydZY5eovz7YgJyHa+OfENndryd9vWZlYB0iC0WMG2fZOs+AKDyK4ONiKvxNcMlt rQ== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by userp2130.oracle.com with ESMTP id 2xrd3urfuh-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 31 Jan 2020 06:57:00 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id 00V6rarj118647; Fri, 31 Jan 2020 06:57:00 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userp3020.oracle.com with ESMTP id 2xva6pwdqt-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 31 Jan 2020 06:57:00 +0000 Received: from abhmp0020.oracle.com (abhmp0020.oracle.com [141.146.116.26]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 00V6uuJ5015354; Fri, 31 Jan 2020 06:56:57 GMT Received: from kili.mountain (/129.205.23.165) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 30 Jan 2020 22:56:56 -0800 Date: Fri, 31 Jan 2020 09:56:47 +0300 From: Dan Carpenter To: Jamal Hadi Salim Cc: Cong Wang , Jiri Pirko , "David S. Miller" , Jakub Kicinski , Mohit Bhasi , "Mohit P. Tahiliani" , "V. Saicharan" , Gautam Ramakrishnan , netdev@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: [PATCH net] net: sched: prevent a use after free Message-ID: <20200131065647.joonbg3wzcw26x3b@kili.mountain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Mailer: git-send-email haha only kidding User-Agent: NeoMutt/20170113 (1.7.2) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9516 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=896 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1911140001 definitions=main-2001310061 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9516 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=960 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1911140001 definitions=main-2001310061 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The code calls kfree_skb(skb); and then re-uses "skb" on the next line. Let's re-order these lines to solve the problem. Fixes: ec97ecf1ebe4 ("net: sched: add Flow Queue PIE packet scheduler") Signed-off-by: Dan Carpenter --- net/sched/sch_fq_pie.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/sched/sch_fq_pie.c b/net/sched/sch_fq_pie.c index bbd0dea6b6b9..78472e0773e9 100644 --- a/net/sched/sch_fq_pie.c +++ b/net/sched/sch_fq_pie.c @@ -349,9 +349,9 @@ static int fq_pie_change(struct Qdisc *sch, struct nlattr *opt, while (sch->q.qlen > sch->limit) { struct sk_buff *skb = fq_pie_qdisc_dequeue(sch); - kfree_skb(skb); len_dropped += qdisc_pkt_len(skb); num_dropped += 1; + kfree_skb(skb); } qdisc_tree_reduce_backlog(sch, num_dropped, len_dropped); -- 2.11.0