From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751046AbdE1IPw (ORCPT ); Sun, 28 May 2017 04:15:52 -0400 Received: from bombadil.infradead.org ([65.50.211.133]:57637 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751022AbdE1IPv (ORCPT ); Sun, 28 May 2017 04:15:51 -0400 Date: Sun, 28 May 2017 01:15:41 -0700 From: Christoph Hellwig To: Kees Cook Cc: kernel-hardening@lists.openwall.com, "David S . Miller" , Laura Abbott , x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 08/20] randstruct: Whitelist NIU struct page overloading Message-ID: <20170528081541.GE22193@infradead.org> References: <1495829844-69341-1-git-send-email-keescook@chromium.org> <1495829844-69341-9-git-send-email-keescook@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1495829844-69341-9-git-send-email-keescook@chromium.org> User-Agent: Mutt/1.8.0 (2017-02-23) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 26, 2017 at 01:17:12PM -0700, Kees Cook wrote: > The NIU ethernet driver intentionally stores a page struct pointer on > top of the "mapping" field. Whitelist this case: > > drivers/net/ethernet/sun/niu.c: In function ‘niu_rx_pkt_ignore’: > drivers/net/ethernet/sun/niu.c:3402:10: note: found mismatched ssa struct pointer types: ‘struct page’ and ‘struct address_space’ > > *link = (struct page *) page->mapping; > ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > Cc: David S. Miller > Signed-off-by: Kees Cook The driver really needs to stop doing this anyway. It would be good to send this out to linux-mm and netdev to come up with a better scheme.