Re: [PATCH] staging: media: atomisp: add missing mutex lock in atomisp_s_fmt_cap

[Abdelrahman Fekry]

Hi Andy,

On Wed, Jul 16, 2025 at 11:11 AM Andy Shevchenko
<andy.shevchenko@xxxxxxxxx> wrote:
>
> On Wed, Jul 16, 2025 at 4:42 AM Abdelrahman Fekry
> <abdelrahmanfekry375@xxxxxxxxx> wrote:
> >
> > The function atomisp_set_fmt() modifies shared device state and expects
> > callers to hold the isp->mutex for synchronization. While most internal
> > callers correctly lock the mutex before invoking atomisp_set_fmt(), the
> > V4L2 ioctl handler atomisp_s_fmt_cap() does not.
> >
> > This results in an unsafe execution path for VIDIOC_S_FMT ioctls
> > (e.g. via v4l2-ctl), where shared structures such as pipe->pix and
> > pipe->frame_info may be modified concurrently without proper protection.
> >
> > - Fix this by explicitly locking isp->mutex in atomisp_s_fmt_cap().
>
> If it's a fix, please add the Fixes tag.
>
will do , thanks.
> ...
>
> > -       return atomisp_set_fmt(vdev, f);
> > +       mutex_lock(&isp->mutex);
> > +       ret = atomisp_set_fmt(vdev, f);
> > +       mutex_unlock(&isp->mutex);
>
> Side note: Can you consider switching the driver to use cleanup.h
> (guard()(), scoped_guard(), __free(), etc)?
will look at it .

Would you please look at this patch series [1] , it hasn't got any feedback
and i have more work that builds on it.

> --
> With Best Regards,
> Andy Shevchenko

Link: https://lore.kernel.org/all/20250712191325.132666-1-abdelrahmanfekry375@xxxxxxxxx/
[1]
Best Regards,
Abdelrahman Fekry