Re: [PATCH] stm: ltdc: fix two incorrect NULL checks on list iterator

[Philippe CORNU]

On 3/28/22 14:37, Raphael Gallais-Pou wrote:
> Hello Xiaomeng
>
> On 3/27/22 07:53, Xiaomeng Tong wrote:
> > The two bugs are here:
> > 	if (encoder) {
> > 	if (bridge && bridge->timings)
> >
> > The list iterator value 'encoder/bridge' will *always* be set and
> > non-NULL by drm_for_each_encoder()/list_for_each_entry(), so it is
> > incorrect to assume that the iterator value will be NULL if the
> > list is empty or no element is found.
> >
> > To fix the bug, use a new variable '*_iter' as the list iterator,
> > while use the old variable 'encoder/bridge' as a dedicated pointer
> > to point to the found element.
> >
> > Cc: stable@xxxxxxxxxxxxxxx
> > Fixes: 99e360442f223 ("drm/stm: Fix bus_flags handling")
> > Signed-off-by: Xiaomeng Tong <xiam0nd.tong@xxxxxxxxx>
> > ---
> >   drivers/gpu/drm/stm/ltdc.c | 16 ++++++++++------
> >   1 file changed, 10 insertions(+), 6 deletions(-)
>
>
> Thanks for your fix
>
> Acked-by: Raphael Gallais-Pou <raphael.gallais-pou@xxxxxxxxxxx>
>
>
> Raphaël Gallais-Pou

Applied on drm-misc-next.
Many thanks for your patch,
Philippe :-)