From patchwork Mon Jul 8 11:16:24 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Dag Moxnes X-Patchwork-Id: 11034923 X-Patchwork-Delegate: jgg@ziepe.ca Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9D26413BD for ; Mon, 8 Jul 2019 11:17:18 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8DA7A27CEE for ; Mon, 8 Jul 2019 11:17:18 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 78CA0285CB; Mon, 8 Jul 2019 11:17:18 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 05BB527F3E for ; Mon, 8 Jul 2019 11:17:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730409AbfGHLRR (ORCPT ); Mon, 8 Jul 2019 07:17:17 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:39644 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730258AbfGHLRR (ORCPT ); Mon, 8 Jul 2019 07:17:17 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x68BEbUZ144983; Mon, 8 Jul 2019 11:16:54 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : mime-version : content-type : content-transfer-encoding; s=corp-2018-07-02; bh=wyEdXnjJ8jw6sAdU9BtEeTeNAhQPGnvYdqq4Yf+RfmY=; b=EYrfpujejJTqx0+2HHciLdDO2gGPwyoRRmV3E7Nh2ivAl011KySpBHyaPVtBRkkzTTbW uhdORuYHtWrZ1c0PKLoyLwQsz6A0rqrIewH6meH2Z523hDUPBQyQCl+30IBQRjqLju90 P3q31NT3cg0pgKnxrG3qRwaHA2MJ5xuwV+nHRy4/Xb6ix094srK+x1d/R8O3KLk/jeaz sY6bQkSlOplZ90iUa0nmelpzKRDgBI9L0pE3dE0i7xB7V7J4za2pBG4fJQk4mU2xh7Lf fES+O8cbpF7edN5wfSFrNFDnY+XlJlUCuyTv0AAZXotZaV3kEimOK+ivCQqQGI4DomXG hA== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by aserp2120.oracle.com with ESMTP id 2tjkkpdsw8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 08 Jul 2019 11:16:54 +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 x68BD0nE176139; Mon, 8 Jul 2019 11:16:54 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userp3020.oracle.com with ESMTP id 2tjjyk57pc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 08 Jul 2019 11:16:53 +0000 Received: from abhmp0010.oracle.com (abhmp0010.oracle.com [141.146.116.16]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x68BGqmU015176; Mon, 8 Jul 2019 11:16:52 GMT Received: from dm-oel.no.oracle.com (/10.172.157.165) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 08 Jul 2019 04:16:51 -0700 From: Dag Moxnes To: dledford@redhat.com, jgg@ziepe.ca, leon@kernel.org, parav@mellanox.com Cc: linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3] RDMA/core: Fix race when resolving IP address Date: Mon, 8 Jul 2019 13:16:24 +0200 Message-Id: <1562584584-13132-1-git-send-email-dag.moxnes@oracle.com> X-Mailer: git-send-email 1.7.1 MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9311 signatures=668688 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1907080145 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9311 signatures=668688 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1907080145 Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Use neighbour lock when copying MAC address from neighbour data struct in dst_fetch_ha. When not using the lock, it is possible for the function to race with neigh_update, causing it to copy an invalid MAC address. It is possible to provoke this error by calling rdma_resolve_addr in a tight loop, while deleting the corresponding ARP entry in another tight loop. This will cause the race shown it the following sample trace: rdma_resolve_addr() rdma_resolve_ip() addr_resolve() addr_resolve_neigh() fetch_ha() dst_fetch_ha() n->nud_state == NUD_VALID and net_ioctl() arp_ioctl() arp_rec_delete() arp_invalidate() neigh_update() __neigh_update() neigh->nud_state = new; Signed-off-by: Dag Moxnes Signed-off-by: Håkon Bugge Reviewed-by: Parav Pandit --- v1 -> v2: * Modified implementation to improve readability v2 -> v3: * Added sample trace as suggested by Parav Pandit * Added Reviewed-by --- drivers/infiniband/core/addr.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/infiniband/core/addr.c b/drivers/infiniband/core/addr.c index 2f7d141598..51323ffbc5 100644 --- a/drivers/infiniband/core/addr.c +++ b/drivers/infiniband/core/addr.c @@ -333,11 +333,14 @@ static int dst_fetch_ha(const struct dst_entry *dst, if (!n) return -ENODATA; - if (!(n->nud_state & NUD_VALID)) { + read_lock_bh(&n->lock); + if (n->nud_state & NUD_VALID) { + memcpy(dev_addr->dst_dev_addr, n->ha, MAX_ADDR_LEN); + read_unlock_bh(&n->lock); + } else { + read_unlock_bh(&n->lock); neigh_event_send(n, NULL); ret = -ENODATA; - } else { - memcpy(dev_addr->dst_dev_addr, n->ha, MAX_ADDR_LEN); } neigh_release(n);