From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759455AbXKBRzA (ORCPT ); Fri, 2 Nov 2007 13:55:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754029AbXKBRyx (ORCPT ); Fri, 2 Nov 2007 13:54:53 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:43120 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753615AbXKBRyw (ORCPT ); Fri, 2 Nov 2007 13:54:52 -0400 Date: Fri, 2 Nov 2007 10:37:58 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Roland Dreier Subject: [patch 4/9] IB/uverbs: Fix checking of userspace object ownership Message-ID: <20071102173758.GE6378@kroah.com> References: <20071102173359.709442489@mini.kroah.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="ib-uverbs-fix-checking-of-userspace-object-ownership.patch" In-Reply-To: <20071102173733.GA6378@kroah.com> User-Agent: Mutt/1.5.16 (2007-06-09) X-Bad-Reply: References and In-Reply-To but no 'Re:' in Subject. Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 2.6.22-stable review patch. If anyone has any objections, please let us know. ------------------ From: Roland Dreier Upstream as cbfb50e6e2e9c580848c0f51d37c24cdfb1cb704 Commit 9ead190b ("IB/uverbs: Don't serialize with ib_uverbs_idr_mutex") rewrote how userspace objects are looked up in the uverbs module's idrs, and introduced a severe bug in the process: there is no checking that an operation is being performed by the right process any more. Fix this by adding the missing check of uobj->context in __idr_get_uobj(). Apparently everyone is being very careful to only touch their own objects, because this bug was introduced in June 2006 in 2.6.18, and has gone undetected until now. Signed-off-by: Roland Dreier Signed-off-by: Greg Kroah-Hartman --- drivers/infiniband/core/uverbs_cmd.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/drivers/infiniband/core/uverbs_cmd.c +++ b/drivers/infiniband/core/uverbs_cmd.c @@ -147,8 +147,12 @@ static struct ib_uobject *__idr_get_uobj spin_lock(&ib_uverbs_idr_lock); uobj = idr_find(idr, id); - if (uobj) - kref_get(&uobj->ref); + if (uobj) { + if (uobj->context == context) + kref_get(&uobj->ref); + else + uobj = NULL; + } spin_unlock(&ib_uverbs_idr_lock); return uobj; --