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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 81F2BC76188 for ; Fri, 19 Jul 2019 04:01:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 53747218A6 for ; Fri, 19 Jul 2019 04:01:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563508892; bh=T9m1EC5vw6Ony5vr7aqVEUoO4PYsNMhEV4akTk7qcXU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=z9Ytos77pjNGAAiyuZNkKisioE8vF2b1AxmSPhZnLxs95U/gDEsoLwHlzB8hWM+FZ fp3nLWwr/pys6D+/0OWuJqgQq2hRSDic21AAuYnP5V8Is71Gn+IlChMukspFudEANs VKAG1sX/Jw52HlM1dE5R7Vqp/JFjcdGhHam0gjUg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729472AbfGSEBb (ORCPT ); Fri, 19 Jul 2019 00:01:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:33092 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729404AbfGSEBY (ORCPT ); Fri, 19 Jul 2019 00:01:24 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 33FDB21851; Fri, 19 Jul 2019 04:01:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563508883; bh=T9m1EC5vw6Ony5vr7aqVEUoO4PYsNMhEV4akTk7qcXU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Up6PljohJ9Evk4434M3BpHN+mI+ufgfOEycmVO1hlEKZPRBMca87OEPYAA3lA8Cqc 4Lmb+tp35ekcwSjI33EjIB+gzLVTsCuS1zOTsVXTKhEZBT5A3SOpDjqAUxQW/iWiJD 9lSJFy008oo+sarcSc7qOqLekyvGA4CIW0CeK934= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Dag Moxnes , =?UTF-8?q?H=C3=A5kon=20Bugge?= , Jason Gunthorpe , Sasha Levin , linux-rdma@vger.kernel.org Subject: [PATCH AUTOSEL 5.2 134/171] RDMA/core: Fix race when resolving IP address Date: Thu, 18 Jul 2019 23:56:05 -0400 Message-Id: <20190719035643.14300-134-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190719035643.14300-1-sashal@kernel.org> References: <20190719035643.14300-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dag Moxnes [ Upstream commit d8d9ec7dc5abbb3f11d866e983c4984f5c2de9d6 ] 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: Jason Gunthorpe Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin --- 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 2f7d14159841..9b76a8fcdd24 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