From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9BF7DC47404 for ; Mon, 7 Oct 2019 06:13:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6F86920867 for ; Mon, 7 Oct 2019 06:13:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="b6Z6RJnw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727253AbfJGGNZ (ORCPT ); Mon, 7 Oct 2019 02:13:25 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:51516 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726202AbfJGGNZ (ORCPT ); Mon, 7 Oct 2019 02:13:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=pfP6drXPoprKVpMZwbtJ9L/Nw9mUyKupJm/GF1sbNHc=; b=b6Z6RJnwPHq7I9g1QevfL56ut uLNea6ljrTVw7c49cfta16/0gOL8KpdOovhRpL3/2GP0rT29ZMiZ/LvJXsdaEn3HV6q3L4rNTDQI3 c+wgg2BG2w4YI7OGepeWYJrSXu0iQENetmCOZ2CNh6qBppccaZQzPm72Ple6H3A1dyTR62NF6Ama7 roHumnpoIHKVkuaCeiTRCSTPSRWtsUtH2EmBlALDWG2Fy1nDlFU7xIt085E15UemeOyU5seWJ9Ael sbgLTsY17kFOx7WvlFoLutLMSuWaoYzYiuXWMSerHROaRg4brFgURyQheim/CFoxHtogJghBd6YZ4 8orT/mAxw==; Received: from hch by bombadil.infradead.org with local (Exim 4.92.2 #3 (Red Hat Linux)) id 1iHMGq-00080T-UU; Mon, 07 Oct 2019 06:13:24 +0000 Date: Sun, 6 Oct 2019 23:13:24 -0700 From: Christoph Hellwig To: Alan Mikhak Cc: linux-kernel@vger.kernel.org, martin.petersen@oracle.com, alexios.zavras@intel.com, ming.lei@redhat.com, gregkh@linuxfoundation.org, tglx@linutronix.de, jgg@ziepe.ca, christophe.leroy@c-s.fr, palmer@sifive.com, paul.walmsley@sifive.com Subject: Re: [PATCH] scatterlist: Validate page before calling PageSlab() Message-ID: <20191007061324.GB17978@infradead.org> References: <1569885755-10947-1-git-send-email-alan.mikhak@sifive.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1569885755-10947-1-git-send-email-alan.mikhak@sifive.com> User-Agent: Mutt/1.12.1 (2019-06-15) 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 30, 2019 at 04:22:35PM -0700, Alan Mikhak wrote: > From: Alan Mikhak > > Modify sg_miter_stop() to validate the page pointer > before calling PageSlab(). This check prevents a crash > that will occur if PageSlab() gets called with a page > pointer that is not backed by page struct. > > A virtual address obtained from ioremap() for a physical > address in PCI address space can be assigned to a > scatterlist segment using the public scatterlist API > as in the following example: As Jason pointed out that is not a valid use of scatterlist. What are you trying to do here at a higher level?