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=-6.9 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 2F117C04A6B for ; Fri, 10 May 2019 09:14:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0AA3B21479 for ; Fri, 10 May 2019 09:14:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727225AbfEJJOe (ORCPT ); Fri, 10 May 2019 05:14:34 -0400 Received: from metis.ext.pengutronix.de ([85.220.165.71]:44587 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727094AbfEJJOe (ORCPT ); Fri, 10 May 2019 05:14:34 -0400 Received: from lupine.hi.pengutronix.de ([2001:67c:670:100:3ad5:47ff:feaf:1a17] helo=lupine) by metis.ext.pengutronix.de with esmtp (Exim 4.89) (envelope-from ) id 1hP1bs-0004X1-DN; Fri, 10 May 2019 11:14:32 +0200 Message-ID: <1557479671.7859.2.camel@pengutronix.de> Subject: Re: [PATCH] reset: fix potential null pointer dereference on pointer dev From: Philipp Zabel To: Colin King Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org, Bartosz Golaszewski Date: Fri, 10 May 2019 11:14:31 +0200 In-Reply-To: <20190509160036.19433-1-colin.king@canonical.com> References: <20190509160036.19433-1-colin.king@canonical.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6-1+deb9u1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 2001:67c:670:100:3ad5:47ff:feaf:1a17 X-SA-Exim-Mail-From: p.zabel@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Colin, [added Bartosz to Cc:] On Thu, 2019-05-09 at 17:00 +0100, Colin King wrote: > From: Colin Ian King > > Pointer dev is being dereferenced when passed to the inlined > functon dev_name, however, dev is later being null checked. > Thus there is a potential null pointer dereference on a null > dev. Fix this by performing the null check on dev before > dereferencing it. > > Addresses-Coverity: ("Dereference before null check") > Fixes: 6691dffab0ab ("reset: add support for non-DT systems") > Signed-off-by: Colin Ian King > --- > drivers/reset/core.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/reset/core.c b/drivers/reset/core.c > index 81ea77cba123..83f1a1d5ee67 100644 > --- a/drivers/reset/core.c > +++ b/drivers/reset/core.c > @@ -691,12 +691,13 @@ __reset_control_get_from_lookup(struct device *dev, const char *con_id, > { > const struct reset_control_lookup *lookup; > struct reset_controller_dev *rcdev; > - const char *dev_id = dev_name(dev); > + const char *dev_id; > struct reset_control *rstc = NULL; > > if (!dev) > return ERR_PTR(-EINVAL); Thank you for the patch. I think this check should be removed instead, though, as __reset_control_get_from_lookup is only ever called from __reset_control_get, right after checking dev->of_node. So dev can not be NULL here. regards Philipp