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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 0132AC433E0 for ; Wed, 1 Jul 2020 11:58:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CC79320780 for ; Wed, 1 Jul 2020 11:58:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593604716; bh=nDHkQnF3GE7LeSK4D2XQD+Jb5LeVxf5LtuLUx72bPl0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=SJ21j36WwdT/x81vEeQXSlAP6HF//1fxS6K5R1GMksGyqWBBXdnY1fgvy/ilJtolG ojr0Dx5nzrXnC2CHnpjCoBg6IAIuxQTrGB6tUVO5ke5k/vYCvwgiEuBFI/LQB0s0Gl JPSKieMA+oAD23PPwxanrw+fNY936hWuDc8flcGg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730471AbgGAL6g (ORCPT ); Wed, 1 Jul 2020 07:58:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:47434 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730133AbgGAL6f (ORCPT ); Wed, 1 Jul 2020 07:58:35 -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 1B7342067D; Wed, 1 Jul 2020 11:58:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593604715; bh=nDHkQnF3GE7LeSK4D2XQD+Jb5LeVxf5LtuLUx72bPl0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=UQcpx0io+u/a7HSMAtKB8tJpIHuA9tVGeE/1lhqC+fzTxXp/XFbgQWyziKZCMUo4V 9OmPXcF+enzCZDJ7tdbDXIq4TLpdl1kiP+3Fm8W6H/jzJqqM0PqwUVP/kzwmM7HC3u ALCWydllZlvVZhfCIR7+pO9v/EQ96aN/uME61ewI= Date: Wed, 1 Jul 2020 13:58:21 +0200 From: Greg Kroah-Hartman To: Chunfeng Yun Cc: Felipe Balbi , Matthias Brugger , Markus Elfring , linux-usb@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [V2 PATCH] usb: mtu3: fix NULL pointer dereference Message-ID: <20200701115821.GA2184169@kroah.com> References: <1593502942-24455-1-git-send-email-chunfeng.yun@mediatek.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1593502942-24455-1-git-send-email-chunfeng.yun@mediatek.com> Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Tue, Jun 30, 2020 at 03:42:22PM +0800, Chunfeng Yun wrote: > Some pointers are dereferenced before successful checks. > > Reported-by: Markus Elfring > Signed-off-by: Chunfeng Yun > --- > v2: nothing changed, but abandon another patch > --- > drivers/usb/mtu3/mtu3_gadget.c | 25 ++++++++++++++++++------- > 1 file changed, 18 insertions(+), 7 deletions(-) > > diff --git a/drivers/usb/mtu3/mtu3_gadget.c b/drivers/usb/mtu3/mtu3_gadget.c > index f93732e..1689ca8 100644 > --- a/drivers/usb/mtu3/mtu3_gadget.c > +++ b/drivers/usb/mtu3/mtu3_gadget.c > @@ -332,14 +332,21 @@ static int mtu3_gadget_queue(struct usb_ep *ep, > > static int mtu3_gadget_dequeue(struct usb_ep *ep, struct usb_request *req) > { > - struct mtu3_ep *mep = to_mtu3_ep(ep); > - struct mtu3_request *mreq = to_mtu3_request(req); > + struct mtu3_ep *mep; > + struct mtu3_request *mreq; > struct mtu3_request *r; > + struct mtu3 *mtu; > unsigned long flags; > int ret = 0; > - struct mtu3 *mtu = mep->mtu; > > - if (!ep || !req || mreq->mep != mep) > + if (!ep || !req) > + return -EINVAL; How will either of those ever be NULL? The kernel will not call this function with either of them being NULL, right? > + > + mep = to_mtu3_ep(ep); > + mtu = mep->mtu; > + > + mreq = to_mtu3_request(req); > + if (mreq->mep != mep) > return -EINVAL; > > dev_dbg(mtu->dev, "%s : req=%p\n", __func__, req); > @@ -373,8 +380,8 @@ static int mtu3_gadget_dequeue(struct usb_ep *ep, struct usb_request *req) > */ > static int mtu3_gadget_ep_set_halt(struct usb_ep *ep, int value) > { > - struct mtu3_ep *mep = to_mtu3_ep(ep); > - struct mtu3 *mtu = mep->mtu; > + struct mtu3_ep *mep; > + struct mtu3 *mtu; > struct mtu3_request *mreq; > unsigned long flags; > int ret = 0; > @@ -382,6 +389,9 @@ static int mtu3_gadget_ep_set_halt(struct usb_ep *ep, int value) > if (!ep) > return -EINVAL; Same here, how can that ever happen? > > + mep = to_mtu3_ep(ep); > + mtu = mep->mtu; > + > dev_dbg(mtu->dev, "%s : %s...", __func__, ep->name); > > spin_lock_irqsave(&mtu->lock, flags); > @@ -422,11 +432,12 @@ static int mtu3_gadget_ep_set_halt(struct usb_ep *ep, int value) > /* Sets the halt feature with the clear requests ignored */ > static int mtu3_gadget_ep_set_wedge(struct usb_ep *ep) > { > - struct mtu3_ep *mep = to_mtu3_ep(ep); > + struct mtu3_ep *mep; > > if (!ep) > return -EINVAL; Again, same here. thanks, greg k-h