From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH 2/2] uio: new driver to support PCI MSI-X Date: Tue, 6 Oct 2015 16:58:20 +0300 Message-ID: <20151006164259-mutt-send-email-mst@redhat.com> References: <1443652138-31782-1-git-send-email-stephen@networkplumber.org> <1443652138-31782-3-git-send-email-stephen@networkplumber.org> <20151001104505-mutt-send-email-mst@redhat.com> <20151005215455.GA7608@redhat.com> <20151006013000-mutt-send-email-mst@redhat.com> <561384EF.8020100@cloudius-systems.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: dev@dpdk.org, hjk@hansjkoch.de, gregkh@linux-foundation.org, linux-kernel@vger.kernel.org To: Vlad Zolotarov Return-path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id 70E56E72 for ; Tue, 6 Oct 2015 15:58:25 +0200 (CEST) Content-Disposition: inline In-Reply-To: <561384EF.8020100@cloudius-systems.com> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Tue, Oct 06, 2015 at 11:23:11AM +0300, Vlad Zolotarov wrote: > Michael, how this or any other related patch is related to the problem u r > describing? > The above ability is there for years and if memory serves me > well it was u who wrote uio_pci_generic with this "security flaw". ;) I answered all this already. This patch enables bus mastering, enables MSI or MSI-X, and requires userspace to map the MSI-X table and read/write the config space. This means that a single userspace bug is enough to corrupt kernel memory. uio_pci_generic does not enable bus mastering or MSI, and it might be a good idea to have uio_pci_generic block access to MSI/MSI-X config. -- MST