From patchwork Wed Apr 6 23:06:23 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bruce Fields X-Patchwork-Id: 691261 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id p36N6ZxP031146 for ; Wed, 6 Apr 2011 23:06:38 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756953Ab1DFXGd (ORCPT ); Wed, 6 Apr 2011 19:06:33 -0400 Received: from fieldses.org ([174.143.236.118]:39839 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756762Ab1DFXGc (ORCPT ); Wed, 6 Apr 2011 19:06:32 -0400 Received: from bfields by fieldses.org with local (Exim 4.72) (envelope-from ) id 1Q7bo0-0001jE-Ey; Wed, 06 Apr 2011 19:06:32 -0400 From: "J. Bruce Fields" To: linux-nfs@vger.kernel.org Cc: "J. Bruce Fields" Subject: [PATCH 4/7] svcrpc: close connection if client sends short packet Date: Wed, 6 Apr 2011 19:06:23 -0400 Message-Id: <1302131186-6578-5-git-send-email-bfields@redhat.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1302131186-6578-1-git-send-email-bfields@redhat.com> References: <1302131186-6578-1-git-send-email-bfields@redhat.com> Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Wed, 06 Apr 2011 23:06:39 +0000 (UTC) If the client sents a record too short to contain even the beginning of the rpc header, then just close the connection. The current code drops the record data and continues. I don't see the point. It's a hopeless situation and simpler just to cut off the connection completely. Signed-off-by: J. Bruce Fields --- net/sunrpc/svcsock.c | 21 +++++++-------------- 1 files changed, 7 insertions(+), 14 deletions(-) diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index 2053259..9d72a79 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -949,6 +949,9 @@ static int svc_tcp_recv_record(struct svc_sock *svsk, struct svc_rqst *rqstp) } } + if (svsk->sk_reclen < 8) + goto err_delete; /* client is nuts. */ + /* Check whether enough data is available */ len = svc_recv_available(svsk); if (len < 0) @@ -1052,20 +1055,10 @@ static int svc_tcp_recvfrom(struct svc_rqst *rqstp) vec[0] = rqstp->rq_arg.head[0]; vlen = PAGE_SIZE; - /* - * We have enough data for the whole tcp record. Let's try and read the - * first 8 bytes to get the xid and the call direction. We can use this - * to figure out if this is a call or a reply to a callback. If - * sk_reclen is < 8 (xid and calldir), then this is a malformed packet. - * In that case, don't bother with the calldir and just read the data. - * It will be rejected in svc_process. - */ - if (len >= 8) { - len = svc_process_calldir(svsk, rqstp, &req, vec); - if (len < 0) - goto err_again; - vlen -= 8; - } + len = svc_process_calldir(svsk, rqstp, &req, vec); + if (len < 0) + goto err_again; + vlen -= 8; pnum = 1; while (vlen < svsk->sk_reclen - 8) {