From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753248Ab2ITHLR (ORCPT ); Thu, 20 Sep 2012 03:11:17 -0400 Received: from cantor2.suse.de ([195.135.220.15]:34187 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750819Ab2ITHLQ (ORCPT ); Thu, 20 Sep 2012 03:11:16 -0400 Date: Thu, 20 Sep 2012 01:11:34 -0600 From: John Jolly To: linux-kernel@vger.kernel.org Cc: Venkat Venkatsubra , netdev@vger.kernel.org Subject: [PATCH] rds: Error on offset mismatch if not loopback Message-ID: <20120920071134.GF14393@linux-tkdk.sfcn.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Attempting an rds connection from the IP address of an IPoIB interface to itself causes a kernel panic due to a BUG_ON() being triggered. Making the test less strict allows rds-ping to work without crashing the machine. A local unprivileged user could use this flaw to crash the sytem. --- net/rds/ib_send.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/net/rds/ib_send.c b/net/rds/ib_send.c index e590949..7920c85 100644 --- a/net/rds/ib_send.c +++ b/net/rds/ib_send.c @@ -544,7 +544,7 @@ int rds_ib_xmit(struct rds_connection *conn, struct rds_message *rm, int flow_controlled = 0; int nr_sig = 0; - BUG_ON(off % RDS_FRAG_SIZE); + BUG_ON(!conn->c_loopback && off % RDS_FRAG_SIZE); BUG_ON(hdr_off != 0 && hdr_off != sizeof(struct rds_header)); /* Do not send cong updates to IB loopback */ -- 1.7.7