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=-6.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 CA033C43381 for ; Tue, 19 Mar 2019 13:11:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9014A213F2 for ; Tue, 19 Mar 2019 13:11:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=skidata.com header.i=@skidata.com header.b="V4rtM+Am" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727018AbfCSNL0 (ORCPT ); Tue, 19 Mar 2019 09:11:26 -0400 Received: from mail1.skidata.com ([91.230.2.99]:45039 "EHLO mail1.skidata.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726464AbfCSNL0 (ORCPT ); Tue, 19 Mar 2019 09:11:26 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=skidata.com; i=@skidata.com; q=dns/txt; s=selector1; t=1553001085; x=1584537085; h=subject:to:cc:references:from:message-id:date: mime-version:in-reply-to:content-transfer-encoding; bh=YZ4J5UTncLJ/PTFt2yYwAjChO7oWMvH/+rMsTnRSgfw=; b=V4rtM+AmerDXPPGQIeVtvjSqr6XaqAIG2LBM0vwmVgUpYkOtd/0Mue79 FbCjwInPRAvGKWJXEHuZ6U7Efhdrw0BV8xJ0xvAGjKYbVxOycB6fFDlFr Auppo1Atvax65Z06Yve1+F3vC60+8F++1qLNA9dVjgh/Lsa4xZ/Vg7LuM xpd7UPIvEd8Ab+o50kG4jl85/d+yTd94zwl6i2edPih8qW1F8G4MLpu4M J8j6cPt5NKXEZ7PQKFnaY757lbI9wmRxlfZJHD4m7ZG6C+Fh169HrLkON yTyOmVgX0ieZY2T4k03Zoz9RT8z07oIpvegTkJCSoLMMELfmKauJBN9zQ Q==; IronPort-SDR: 5j2gXmfIar4y/PK4X+4aMPH0oLHne63aFz8r1AihWn59PVIvIuiYdsJYaat5I7hg1rSjjyQl0T iVQmYhbo47DUcX8Ousg9Pr8sl7+eqmkl69PMMkL3zIR6UamJFjK+kuIwDekHG5K0uaGZPPcHah Oiz9p4mXVnSucZSlrPuM6CKwFhoHj7kyn73v0/bhQqbRlJFwJWfCrw6LDs4nEaxcsmNWx9HTgF 40LzYNyWzlRrlSrA1JiP4oHNb0eYs4SKdSGbLlmq1rOVWhlHSY/uF1DICln9UrI4SVcPo38ml7 zag= X-IronPort-AV: E=Sophos;i="5.58,498,1544482800"; d="scan'208";a="15841402" Subject: Re: [PATCH] usb: usb251xb: fix to avoid potential NULL pointer dereference To: Aditya Pakki CC: , Greg Kroah-Hartman , , References: <20190318235605.11055-1-pakki001@umn.edu> From: Richard Leitner Message-ID: <3579fc19-dde7-968b-3918-39f1cc4ee3bc@skidata.com> Date: Tue, 19 Mar 2019 14:11:23 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.1 MIME-Version: 1.0 In-Reply-To: <20190318235605.11055-1-pakki001@umn.edu> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.111.22] X-ClientProxiedBy: sdex5srv.skidata.net (192.168.111.83) To sdex5srv.skidata.net (192.168.111.83) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 19/03/2019 00:56, Aditya Pakki wrote: > of_match_device in usb251xb_probe can fail and returns a NULL pointer. > The patch avoids a potential NULL pointer dereference in this scenario. > > Signed-off-by: Aditya Pakki > --- > drivers/usb/misc/usb251xb.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/usb/misc/usb251xb.c b/drivers/usb/misc/usb251xb.c > index 4d72b7d1d383..fe5266dc8864 100644 > --- a/drivers/usb/misc/usb251xb.c > +++ b/drivers/usb/misc/usb251xb.c > @@ -612,6 +612,8 @@ static int usb251xb_probe(struct usb251xb *hub) > dev); > int err; > > + if (!of_id) > + return -ENODEV; Hi Aditya, thanks for finding this issue! Nonetheless I'd prefer to change this to not return here but rather do something like: if (np && of_id) { So we still may bring up the hub in its default config in scenarios without dt/of... Any comments/objections on that? regards;Richard.L > if (np) { > err = usb251xb_get_ofdata(hub, > (struct usb251xb_data *)of_id->data); >