From: Peter Chen <peter.chen@nxp.com>
To: Jisheng Zhang <jszhang@marvell.com>
Cc: Stefan Wahren <stefan.wahren@i2se.com>,
"gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH] usb: chipidea: udc: fix NULL pointer dereference if udc_start failed
Date: Wed, 26 Apr 2017 17:05:02 +0800 [thread overview]
Message-ID: <20170426090502.GB4375@b29397-desktop> (raw)
In-Reply-To: <20170426162526.7c8ef827@xhacker>
On Wed, Apr 26, 2017 at 04:25:26PM +0800, Jisheng Zhang wrote:
> On Tue, 25 Apr 2017 17:21:59 +0200
> Stefan Wahren <stefan.wahren@i2se.com> wrote:
>
> > Am 25.04.2017 um 11:20 schrieb Peter Chen:
> > >
> > >>>> diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
> > >>>> index f88e9157fad0..60a786c87c06 100644
> > >>>> --- a/drivers/usb/chipidea/udc.c
> > >>>> +++ b/drivers/usb/chipidea/udc.c
> > >>>> @@ -1984,6 +1984,7 @@ static void udc_id_switch_for_host(struct
> > >>>> ci_hdrc *ci) int ci_hdrc_gadget_init(struct ci_hdrc *ci) {
> > >>>> struct ci_role_driver *rdrv;
> > >>>> + int ret;
> > >>>>
> > >>>> if (!hw_read(ci, CAP_DCCPARAMS, DCCPARAMS_DC))
> > >>>> return -ENXIO;
> > >>>> @@ -1996,7 +1997,10 @@ int ci_hdrc_gadget_init(struct ci_hdrc *ci)
> > >>>> rdrv->stop = udc_id_switch_for_host;
> > >>>> rdrv->irq = udc_irq;
> > >>>> rdrv->name = "gadget";
> > >>>> - ci->roles[CI_ROLE_GADGET] = rdrv;
> > >>>>
> > >>>> - return udc_start(ci);
> > >>>> + ret = udc_start(ci);
> > >>>> + if (!ret)
> > >>>> + ci->roles[CI_ROLE_GADGET] = rdrv;
> > >>>> +
> > >>>> + return ret;
> > >>>> }
> > >>>> --
> > >>> Thanks for fixing it. In fact, we'd better return failure if ret &&
> > >>> ret != -ENXIO at probe, it stands for initialization for host or
> > >>> gadget has failed.
> > >>>
> > >> I got your meaning. I'll cook v2. I don't have preference, since either one can fix the
> > >> issue.
> > >>
> > > Both are needed, you don't need to send this one again. Only a new one, thanks.
> >
> > I'm not sure how easy it is to reproduce the issue.
>
> It's easy to reproduce it (100%) on arm64 platforms after commit
> 1dccb598df549 ("arm64: simplify dma_get_ops"). This commit could
> make all dma related operations failed, then udc_start() would fail
> with -ENOMEM.
>
> On other platforms, it's not easy.
>
> >
> > Shouldn't make a Fixes tag sense at least?
>
> maybe 3f124d233e97 ("usb: chipidea: add role init and destroy APIs"
I will cc stable, thanks.
--
Best Regards,
Peter Chen
prev parent reply other threads:[~2017-04-26 9:25 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-24 12:35 [PATCH] usb: chipidea: udc: fix NULL pointer dereference if udc_start failed Jisheng Zhang
2017-04-25 8:29 ` Peter Chen
2017-04-25 9:11 ` Jisheng Zhang
2017-04-25 9:20 ` Peter Chen
2017-04-25 15:21 ` Stefan Wahren
2017-04-26 8:25 ` Jisheng Zhang
2017-04-26 9:05 ` Peter Chen [this message]
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