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=-8.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 72CEDC10F14 for ; Thu, 10 Oct 2019 05:20:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4C79C2190F for ; Thu, 10 Oct 2019 05:20:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570684832; bh=OjsgxPp6g+K1tFbCY+kL0wFsiuNuwU5K3PbXoj4jLJE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=kC79R3eyzUJ2n17Ft1q7HvhJVX22BPL2iiX/1h0txBhDZG/IIx7fSKrunyP8bwYi2 diWmK55Pa3xz71XlvzXoDhTbs+9iasGDL4IPKoFgJrXU9aZEOYpdwWBhi4HMKVMGZA Oj41HmvyRpkNxytyFTcRk9h1hKBxFVupxiPYBu28= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728388AbfJJFU3 (ORCPT ); Thu, 10 Oct 2019 01:20:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:55746 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726612AbfJJFU2 (ORCPT ); Thu, 10 Oct 2019 01:20:28 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 99A4120659; Thu, 10 Oct 2019 05:20:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570684828; bh=OjsgxPp6g+K1tFbCY+kL0wFsiuNuwU5K3PbXoj4jLJE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=sc4iSPZ/mNe+m5vif9BPR7tZwp8Tg8nuta2n72t5jpWVATAp1RYAVodrXBs8blK9Z b/ijt0CZYvkeqzNHhjeo7BRT3/qzDf9TYh+RfRv0lZCfX9dmCinGcVHFbddvzjGBDY ltAxXmXLDEdR/5gQioNmIdYE2kIn3YsR8ryPxGV4= Date: Thu, 10 Oct 2019 07:20:25 +0200 From: Greg Kroah-Hartman To: Yizhuo Cc: Alan Stern , Kai-Heng Feng , Mathias Nyman , Thinh Nguyen , Douglas Anderson , Nicolas Saenz Julienne , Jan-Marek Glogowski , Mathieu Malaterre , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] USB: core: Fix potental Null Pointer dereference Message-ID: <20191010052025.GA235874@kroah.com> References: <20191010010205.25739-1-yzhai003@ucr.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191010010205.25739-1-yzhai003@ucr.edu> User-Agent: Mutt/1.12.2 (2019-09-21) Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Wed, Oct 09, 2019 at 06:02:02PM -0700, Yizhuo wrote: > Inside function usb_device_is_owned(), usb_hub_to_struct_hub() > could return NULL but there's no check before its dereference, > which is potentially unsafe. > > Signed-off-by: Yizhuo > --- > drivers/usb/core/hub.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c > index 236313f41f4a..8d628c8e0c1b 100644 > --- a/drivers/usb/core/hub.c > +++ b/drivers/usb/core/hub.c > @@ -1977,7 +1977,7 @@ bool usb_device_is_owned(struct usb_device *udev) > if (udev->state == USB_STATE_NOTATTACHED || !udev->parent) > return false; > hub = usb_hub_to_struct_hub(udev->parent); > - return !!hub->ports[udev->portnum - 1]->port_owner; > + return hub && !!hub->ports[udev->portnum - 1]->port_owner; How can hub ever not be valid? thanks, greg k-h