Re: [RESEND PATCH v2] media: mtk-jpeg: Fix use after free bug due to uncanceled work

[Alexandre Mergnat]

On 18/07/2023 05:07, Zheng Hacker wrote:
> Friendly ping
>
> Zheng Hacker <hackerzheng666@xxxxxxxxx> 于2023年7月16日周日 00:08写道：
> > Hi,
> >
> > This issue has not been resolved for a long time. Is there anyone who can help?
> >
> > Best regards,
> > Zheng
> >
> > Alexandre Mergnat <amergnat@xxxxxxxxxxxx> 于2023年7月7日周五 22:11写道：
> > > On 07/07/2023 11:24, Zheng Wang wrote:
> > > > In mtk_jpeg_probe, &jpeg->job_timeout_work is bound with
> > > > mtk_jpeg_job_timeout_work. Then mtk_jpeg_dec_device_run
> > > > and mtk_jpeg_enc_device_run may be called to start the
> > > > work.
> > > > If we remove the module which will call mtk_jpeg_remove
> > > > to make cleanup, there may be a unfinished work. The
> > > > possible sequence is as follows, which will cause a
> > > > typical UAF bug.
> > > >
> > > > Fix it by canceling the work before cleanup in the mtk_jpeg_remove
> > > >
> > > > CPU0                  CPU1
> > > >
> > > >                       |mtk_jpeg_job_timeout_work
> > > > mtk_jpeg_remove     |
> > > >     v4l2_m2m_release  |
> > > >       kfree(m2m_dev); |
> > > >                       |
> > > >                       | v4l2_m2m_get_curr_priv
> > > >                       |   m2m_dev->curr_ctx //use
> > >
> > > Reviewed-by: Alexandre Mergnat <amergnat@xxxxxxxxxxxx>
> > >
> > > --
> > > Regards,
> > > Alexandre

Hi Zheng,

If you asking me to merge patch, sorry but I can't, I'm just a reviewer. 
I invite you to ping the maintainers directly:

Bin Liu <bin.liu@xxxxxxxxxxxx> (supporter:MEDIATEK JPEG DRIVER)
Mauro Carvalho Chehab <mchehab@xxxxxxxxxx> (maintainer:MEDIA INPUT 
INFRASTRUCTURE (V4L/DVB))
Matthias Brugger <matthias.bgg@xxxxxxxxx> (maintainer:ARM/Mediatek SoC 
support)

Otherwise, I misunderstood what you asking me. If so, can you rephrase 
your question please?

--
Regards,
Alexandre