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=-9.8 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, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 1DB7BC004EF for ; Tue, 9 Jul 2019 11:51:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E0B6D214AF for ; Tue, 9 Jul 2019 11:51:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="pEUPLdfB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726025AbfGILvl (ORCPT ); Tue, 9 Jul 2019 07:51:41 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:52844 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725947AbfGILvl (ORCPT ); Tue, 9 Jul 2019 07:51:41 -0400 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x69BnWKa014504; Tue, 9 Jul 2019 11:50:55 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=xtBXsTaJ7dIMqNvrbwXEX92Vq1lmGGW+oyu54odZQc0=; b=pEUPLdfBRoms5xAoDhCqEkMUqR0uWVmyUahw9Zl3O+pgyWQ8l0C/PqTC7FI/1igtx100 GhuB7jhGhb9HhaVZw5Fs7Zc54RqedYAPXcQptenp6AchPjPg8fw8PUsAZNfktFiI+IX8 ovepCSnZ5s4panBc6Wf1pHhK+h/vs+NjUtr8TtQmL/VGK/1zp0ygByQFdDfgd5XIeeAu oKv44wtnx9sn7NpdBDvk9D23WDOn/pUgYH8EFmMFDq6eTIcRmbrSasfCrw08dFIRdRU5 7jq3jycQ9PtZLEA6/glPjLgjoTgxcjJlUcu3V9ozUrqXcXbt/DR7Vh2PdPFWWmI9XdTQ qA== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by userp2120.oracle.com with ESMTP id 2tjm9qksj4-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 09 Jul 2019 11:50:54 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x69Blnl9160141; Tue, 9 Jul 2019 11:50:53 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserp3020.oracle.com with ESMTP id 2tmmh2wve0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 09 Jul 2019 11:50:53 +0000 Received: from abhmp0016.oracle.com (abhmp0016.oracle.com [141.146.116.22]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x69BoqbV023270; Tue, 9 Jul 2019 11:50:52 GMT Received: from dm-oel.no.oracle.com (/10.172.157.165) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 09 Jul 2019 04:50:52 -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 v4] RDMA/core: Fix race when resolving IP address Date: Tue, 9 Jul 2019 13:50:26 +0200 Message-Id: <1562673026-31996-1-git-send-email-dag.moxnes@oracle.com> X-Mailer: git-send-email 1.7.1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9312 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-1907090146 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9312 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-1907090146 Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Use the neighbour lock when copying the MAC address from the 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 torn MAC address: rdma_resolve_addr() rdma_resolve_ip() addr_resolve() addr_resolve_neigh() fetch_ha() dst_fetch_ha() memcpy(dev_addr->dst_dev_addr, n->ha, MAX_ADDR_LEN) and net_ioctl() arp_ioctl() arp_rec_delete() arp_invalidate() neigh_update() __neigh_update() memcpy(&neigh->ha, lladdr, dev->addr_len) 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. Fixes: 51d45974515c ("infiniband: addr: Consolidate code to fetch neighbour hardware address from dst.") Signed-off-by: Dag Moxnes Signed-off-by: Håkon Bugge Reviewed-by: Parav Pandit Signed-off-by: Jason Gunthorpe --- drivers/infiniband/core/addr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/infiniband/core/addr.c b/drivers/infiniband/core/addr.c index 2f7d141598..9b76a8fcdd 100644 --- a/drivers/infiniband/core/addr.c +++ b/drivers/infiniband/core/addr.c @@ -337,7 +337,7 @@ static int dst_fetch_ha(const struct dst_entry *dst, neigh_event_send(n, NULL); ret = -ENODATA; } else { - memcpy(dev_addr->dst_dev_addr, n->ha, MAX_ADDR_LEN); + neigh_ha_snapshot(dev_addr->dst_dev_addr, n, dst->dev); } neigh_release(n); -- 2.20.1