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,HEADER_FROM_DIFFERENT_DOMAINS,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 54382C76186 for ; Mon, 29 Jul 2019 20:02:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1D9E2205F4 for ; Mon, 29 Jul 2019 20:02:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564430531; bh=fQxvfeb8Oau7nGkThdwi/x3SxOWcDMjxQ9XNvSRw1Rw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=vhwivTyEDkTMlrmG1YNtnnGsZpshifDLqdxf6geRnK27buGAG8etJoA+QyqRqboW1 Iy4uIumIuXTjceW6NdMkw/rDuZzQcX1LO3RKjaq4KsWlHWWuLBSxI3nGlF4BXu92F3 i2DyEltlpGEZf7Gx30T9gCzMKr02bqsmyKZVaS/Y= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390876AbfG2UBK (ORCPT ); Mon, 29 Jul 2019 16:01:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:43108 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390800AbfG2Tvg (ORCPT ); Mon, 29 Jul 2019 15:51:36 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7C88E204EC; Mon, 29 Jul 2019 19:51:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564429896; bh=fQxvfeb8Oau7nGkThdwi/x3SxOWcDMjxQ9XNvSRw1Rw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=znLvocsgLa9YSqIBZTMG5DIwbdEQu2vO7gOaMz+iJnqak2jh3qNxfOfHGjlEutkkW pgPHPbAQp435CD8rtpfRawQfzKtP9AbDCLqykotzOuLnnFsN7CTPGRW79//28N1Gsl xlnxbGUfEBnlqCpRkLos9VKrvll72odLbvWj2aJ4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dag Moxnes , =?UTF-8?q?H=C3=A5kon=20Bugge?= , Jason Gunthorpe , Sasha Levin Subject: [PATCH 5.2 131/215] RDMA/core: Fix race when resolving IP address Date: Mon, 29 Jul 2019 21:22:07 +0200 Message-Id: <20190729190802.158910889@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190729190739.971253303@linuxfoundation.org> References: <20190729190739.971253303@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ 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