[FFmpeg-devel] [PATCH 4/6] avcodec/rv60dec: Check NEXT/LAST availability

[Michael Niedermayer]

Hi Peter

On Sun, Dec 08, 2024 at 06:35:21PM +1100, Peter Ross wrote:
> On Sun, Dec 08, 2024 at 04:57:01AM +0100, Michael Niedermayer wrote:
> > Fixes: NULL ptr use
> > Fixes: 378634700/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_RV60_fuzzer-5008344043028480
> > 
> > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> > Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> > ---
> >  libavcodec/rv60dec.c | 17 +++++++++++++----
> >  1 file changed, 13 insertions(+), 4 deletions(-)
> > 
> > diff --git a/libavcodec/rv60dec.c b/libavcodec/rv60dec.c
> > index 4cc71dcd6ee..528f91acf05 100644
> > --- a/libavcodec/rv60dec.c
> > +++ b/libavcodec/rv60dec.c
> > @@ -1745,15 +1745,24 @@ static int decode_cu_r(RV60Context * s, AVFrame * frame, ThreadContext * thread,
> >              bx = mv_x << 2;
> >              by = mv_y << 2;
> >  
> > +            if (!(mv.mvref&2)) {
> 
> hi michael. please insert some space around the & symbol
> 
> > +                if (!s->last_frame[LAST_PIC]->data[0]) {
> > +                    av_log(s->avctx, AV_LOG_ERROR, "missing reference frame\n");
> > +                    return AVERROR_INVALIDDATA;
> > +                }
> > +            }
> > +            if (mv.mvref & 6) {
> > +                if (!s->last_frame[NEXT_PIC]->data[0]) {
> > +                    av_log(s->avctx, AV_LOG_ERROR, "missing reference frame\n");
> > +                    return AVERROR_INVALIDDATA;
> > +                }
> > +            }
> > +
> >              switch (mv.mvref) {
> >              case MVREF_REF0:
> >                  mc(s, frame->data, frame->linesize, s->last_frame[LAST_PIC], bx, by, bw, bh, mv.f_mv, 0);
> >                  break;
> >              case MVREF_REF1:
> > -                if (!s->last_frame[NEXT_PIC]->data[0]) {
> > -                    av_log(s->avctx, AV_LOG_ERROR, "missing reference frame\n");
> > -                    return AVERROR_INVALIDDATA;
> > -                }
> >                  mc(s, frame->data, frame->linesize, s->last_frame[NEXT_PIC], bx, by, bw, bh, mv.f_mv, 0);
> >                  break;
> >              case MVREF_BREF:
> 
> suggest also setting enum MVREF_NONE = 0 higher up in the file, so it is clear
> to readers these enums are ordered deliberately.
> 
> enum MVRefEnum {
>       MVREF_NONE = 0
>       MVREF_REF0,

will apply with these changes

thx

[...]

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Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

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