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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 50397C169C4 for ; Mon, 11 Feb 2019 16:56:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1653721B69 for ; Mon, 11 Feb 2019 16:56:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727707AbfBKQ4Q (ORCPT ); Mon, 11 Feb 2019 11:56:16 -0500 Received: from metis.ext.pengutronix.de ([85.220.165.71]:34825 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726366AbfBKQ4Q (ORCPT ); Mon, 11 Feb 2019 11:56:16 -0500 Received: from kresse.hi.pengutronix.de ([2001:67c:670:100:1d::2a]) by metis.ext.pengutronix.de with esmtp (Exim 4.89) (envelope-from ) id 1gtEsI-0001OV-SV; Mon, 11 Feb 2019 17:56:06 +0100 Message-ID: <1549904165.2546.14.camel@pengutronix.de> Subject: Re: [PATCH v2 1/2] pci: imx6: avoid dereferencing program counter from user mode From: Lucas Stach To: Stefan Agner , hongxing.zhu@nxp.com Cc: robin.murphy@arm.com, tpiepho@impinj.com, linux@armlinux.org.uk, leonard.crestez@nxp.com, andrew.smirnov@gmail.com, festevam@gmail.com, lorenzo.pieralisi@arm.com, bhelgaas@google.com, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Date: Mon, 11 Feb 2019 17:56:05 +0100 In-Reply-To: <20181204132733.14422-1-stefan@agner.ch> References: <20181204132733.14422-1-stefan@agner.ch> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6-1+deb9u1 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::2a X-SA-Exim-Mail-From: l.stach@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-pci@vger.kernel.org Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Am Dienstag, den 04.12.2018, 14:27 +0100 schrieb Stefan Agner: > The custom fault handler is currently only meant to handle kernel > mode bus faults. Exit in case the abort happened in user mode. > > Signed-off-by: Stefan Agner Reviewed-by: Lucas Stach > --- >  drivers/pci/controller/dwc/pci-imx6.c | 10 ++++++++-- >  1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c > index 69f86234f7c0..54a29e441303 100644 > --- a/drivers/pci/controller/dwc/pci-imx6.c > +++ b/drivers/pci/controller/dwc/pci-imx6.c > @@ -270,8 +270,14 @@ static int imx6q_pcie_abort_handler(unsigned long addr, >   unsigned int fsr, struct pt_regs *regs) >  { >   unsigned long pc = instruction_pointer(regs); > - unsigned long instr = *(unsigned long *)pc; > - int reg = (instr >> 12) & 15; > + unsigned long instr; > + int reg; > + > + if (user_mode(regs)) > + return 1; > + > + instr = *(unsigned long *)pc; > + reg = (instr >> 12) & 15; >   >   /* >    * If the instruction being executed was a read,