Re: [PATCH] accel/ivpu: prevent uninitialized data bug in debugfs

[Wachowski, Karol]

On 25-May-26 9:25, Wachowski, Karol wrote:
> On 25-May-26 9:14, Dan Carpenter wrote:
> > The simple_write_to_buffer() will only initialize data starting from
> > the *pos offset so if it's non-zero then the first part of the buffer
> > uninitialized.  Really, if *pos is non-zero then this code won't work
> > so just check for that at the start of the function.
> >
> > Fixes: 320323d2e545 ("accel/ivpu: Add debugfs interface for setting 
> > HWS priority bands")
> > Signed-off-by: Dan Carpenter <error27@xxxxxxxxx>
> > ---
> >   drivers/accel/ivpu/ivpu_debugfs.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/accel/ivpu/ivpu_debugfs.c b/drivers/accel/ivpu/ 
> > ivpu_debugfs.c
> > index 189dbe94cf14..dc20bc73c6ed 100644
> > --- a/drivers/accel/ivpu/ivpu_debugfs.c
> > +++ b/drivers/accel/ivpu/ivpu_debugfs.c
> > @@ -450,7 +450,7 @@ priority_bands_fops_write(struct file *file, const 
> > char __user *user_buf, size_t
> >       u32 band;
> >       int ret;
> > -    if (size >= sizeof(buf))
> > +    if (*pos != 0 || size >= sizeof(buf))
> >           return -EINVAL;
> >       ret = simple_write_to_buffer(buf, sizeof(buf) - 1, pos, 
> > user_buf, size);
>
> Thanks for submission.
>
> Reviewed-by: Karol Wachowski <karol.wachowski@xxxxxxxxxxxxxxx>

Applied to drm-misc-fixes.