Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754176AbdDJQq3 (ORCPT ); Mon, 10 Apr 2017 12:46:29 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:34968 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754158AbdDJQq0 (ORCPT ); Mon, 10 Apr 2017 12:46:26 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chuck Lever , "J. Bruce Fields" , Sasha Levin Subject: [PATCH 4.9 075/152] svcauth_gss: Close connection when dropping an incoming message Date: Mon, 10 Apr 2017 18:42:07 +0200 Message-Id: <20170410164203.994556387@linuxfoundation.org> X-Mailer: git-send-email 2.12.2 In-Reply-To: <20170410164159.934755016@linuxfoundation.org> References: <20170410164159.934755016@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2969 Lines: 94 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chuck Lever [ Upstream commit 4d712ef1db05c3aa5c3b690a50c37ebad584c53f ] S5.3.3.1 of RFC 2203 requires that an incoming GSS-wrapped message whose sequence number lies outside the current window is dropped. The rationale is: The reason for discarding requests silently is that the server is unable to determine if the duplicate or out of range request was due to a sequencing problem in the client, network, or the operating system, or due to some quirk in routing, or a replay attack by an intruder. Discarding the request allows the client to recover after timing out, if indeed the duplication was unintentional or well intended. However, clients may rely on the server dropping the connection to indicate that a retransmit is needed. Without a connection reset, a client can wait forever without retransmitting, and the workload just stops dead. I've reproduced this behavior by running xfstests generic/323 on an NFSv4.0 mount with proto=rdma and sec=krb5i. To address this issue, have the server close the connection when it silently discards an incoming message due to a GSS sequence number problem. There are a few other places where the server will never reply. Change those spots in a similar fashion. Signed-off-by: Chuck Lever Signed-off-by: J. Bruce Fields Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/sunrpc/auth_gss/svcauth_gss.c | 2 +- net/sunrpc/svc.c | 14 +++++++++----- 2 files changed, 10 insertions(+), 6 deletions(-) --- a/net/sunrpc/auth_gss/svcauth_gss.c +++ b/net/sunrpc/auth_gss/svcauth_gss.c @@ -1548,7 +1548,7 @@ complete: ret = SVC_COMPLETE; goto out; drop: - ret = SVC_DROP; + ret = SVC_CLOSE; out: if (rsci) cache_put(&rsci->h, sn->rsc_cache); --- a/net/sunrpc/svc.c +++ b/net/sunrpc/svc.c @@ -1155,8 +1155,7 @@ svc_process_common(struct svc_rqst *rqst case SVC_DENIED: goto err_bad_auth; case SVC_CLOSE: - if (test_bit(XPT_TEMP, &rqstp->rq_xprt->xpt_flags)) - svc_close_xprt(rqstp->rq_xprt); + goto close; case SVC_DROP: goto dropit; case SVC_COMPLETE: @@ -1246,7 +1245,7 @@ svc_process_common(struct svc_rqst *rqst sendit: if (svc_authorise(rqstp)) - goto dropit; + goto close; return 1; /* Caller can now send it */ dropit: @@ -1254,11 +1253,16 @@ svc_process_common(struct svc_rqst *rqst dprintk("svc: svc_process dropit\n"); return 0; + close: + if (test_bit(XPT_TEMP, &rqstp->rq_xprt->xpt_flags)) + svc_close_xprt(rqstp->rq_xprt); + dprintk("svc: svc_process close\n"); + return 0; + err_short_len: svc_printk(rqstp, "short len %Zd, dropping request\n", argv->iov_len); - - goto dropit; /* drop request */ + goto close; err_bad_rpc: serv->sv_stats->rpcbadfmt++;