lkml.org 
[lkml]   [2017]   [Apr]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] usb: chipidea: udc: fix NULL pointer dereference if udc_start failed
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"

\
 
 \ /
  Last update: 2017-04-26 10:31    [W:0.060 / U:0.016 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site