Thank you, Frank
Fixed by v2
On Mon, Apr 22, 2024 at 12:34 AM Frank Plowman <p...@frankplowman.com>
wrote:
> On 21/04/2024 15:52, Nuo Mi wrote:
> > For some error bitstreams, a CTU belongs to two slices/entry points.
> > If the decoder initializes and submmits the CTU task twice, it may crash
> the program
> > or cause it to enter an infinite loop.
> >
> > Reported-by: Frank Plowman <p...@frankplowman.com>
> > ---
> > libavcodec/vvc/dec.c | 7 +++++--
> > libavcodec/vvc/thread.c | 43 ++++++++++++++++++++++++++++-------------
> > libavcodec/vvc/thread.h | 2 +-
> > 3 files changed, 36 insertions(+), 16 deletions(-)
> >
> > diff --git a/libavcodec/vvc/dec.c b/libavcodec/vvc/dec.c
> > index 6aeec27eaf..4f7d184e43 100644
> > --- a/libavcodec/vvc/dec.c
> > +++ b/libavcodec/vvc/dec.c
> > @@ -893,10 +893,13 @@ static int wait_delayed_frame(VVCContext *s,
> AVFrame *output, int *got_output)
> >
> > static int submit_frame(VVCContext *s, VVCFrameContext *fc, AVFrame
> *output, int *got_output)
> > {
> > - int ret;
> > + int ret = ff_vvc_frame_submit(s, fc);
> > + if (ret < 0)
> > + return ret;
> > +
> > s->nb_frames++;
> > s->nb_delayed++;
> > - ff_vvc_frame_submit(s, fc);
> > +
> > if (s->nb_delayed >= s->nb_fcs) {
> > if ((ret = wait_delayed_frame(s, output, got_output)) < 0)
> > return ret;
> > diff --git a/libavcodec/vvc/thread.c b/libavcodec/vvc/thread.c
> > index 01c3ff75b1..3b27811db2 100644
> > --- a/libavcodec/vvc/thread.c
> > +++ b/libavcodec/vvc/thread.c
> > @@ -124,11 +124,17 @@ static void task_init(VVCTask *t, VVCTaskStage
> stage, VVCFrameContext *fc, const
> > atomic_store(&t->target_inter_score, 0);
> > }
> >
> > -static void task_init_parse(VVCTask *t, SliceContext *sc, EntryPoint
> *ep, const int ctu_idx)
> > +static int task_init_parse(VVCTask *t, SliceContext *sc, EntryPoint
> *ep, const int ctu_idx)
> > {
> > + if (t->sc) {
> > + // the task already inited, error bitstream
> > + return AVERROR_INVALIDDATA;
> > + }
> > t->sc = sc;
> > t->ep = ep;
> > t->ctu_idx = ctu_idx;
> > +
> > + return 0;
> > }
> >
> > static uint8_t task_add_score(VVCTask *t, const VVCTaskStage stage)
> > @@ -758,24 +764,35 @@ static void submit_entry_point(VVCContext *s,
> VVCFrameThread *ft, SliceContext *
> > frame_thread_add_score(s, ft, t->rx, t->ry, VVC_TASK_STAGE_PARSE);
> > }
> >
> > -void ff_vvc_frame_submit(VVCContext *s, VVCFrameContext *fc)
> > +int ff_vvc_frame_submit(VVCContext *s, VVCFrameContext *fc)
> > {
> > VVCFrameThread *ft = fc->ft;
> >
> > - for (int i = 0; i < fc->nb_slices; i++) {
> > - SliceContext *sc = fc->slices[i];
> > - for (int j = 0; j < sc->nb_eps; j++) {
> > - EntryPoint *ep = sc->eps + j;
> > - for (int k = ep->ctu_start; k < ep->ctu_end; k++) {
> > - const int rs = sc->sh.ctb_addr_in_curr_slice[k];
> > - VVCTask *t = ft->tasks + rs;
> > -
> > - task_init_parse(t, sc, ep, k);
> > - check_colocation(s, t);
> > + // We'll handle this in two passes:
> > + // Pass 0 to initialize tasks with parser, this will help detect
> bit stream error
> > + // Pass 1 to shedule location check and submit the entry point
> > + for (int pass = 0; pass < 2; pass++) {
> > + for (int i = 0; i < fc->nb_slices; i++) {
> > + SliceContext *sc = fc->slices[i];
> > + for (int j = 0; j < sc->nb_eps; j++) {
> > + EntryPoint *ep = sc->eps + j;
> > + for (int k = ep->ctu_start; k < ep->ctu_end; k++) {
> > + const int rs = sc->sh.ctb_addr_in_curr_slice[k];
> > + VVCTask *t = ft->tasks + rs;
> > + if (pass) {
> > + check_colocation(s, t);
> > + } else {
> > + const int ret = task_init_parse(t, sc, ep, k);
> > + if (ret < 0)
> > + return ret;
> > + }
> > + }
> > + if (pass)
> > + submit_entry_point(s, ft, sc, ep);
> > }
> > - submit_entry_point(s, ft, sc, ep);
> > }
> > }
> > + return 0;
> > }
> >
> > int ff_vvc_frame_wait(VVCContext *s, VVCFrameContext *fc)
> > diff --git a/libavcodec/vvc/thread.h b/libavcodec/vvc/thread.h
> > index 55bb4ea244..8ac59b2ecf 100644
> > --- a/libavcodec/vvc/thread.h
> > +++ b/libavcodec/vvc/thread.h
> > @@ -30,7 +30,7 @@ void ff_vvc_executor_free(struct AVExecutor **e);
> >
> > int ff_vvc_frame_thread_init(VVCFrameContext *fc);
> > void ff_vvc_frame_thread_free(VVCFrameContext *fc);
> > -void ff_vvc_frame_submit(VVCContext *s, VVCFrameContext *fc);
> > +int ff_vvc_frame_submit(VVCContext *s, VVCFrameContext *fc);
> > int ff_vvc_frame_wait(VVCContext *s, VVCFrameContext *fc);
> >
> > #endif // AVCODEC_VVC_THREAD_H
>
> This patch fixes most of the fuzz bitstreams I have which enter infinite
> loops, but also introduces a regression, turning some other bitstreams
> which were okay before into infinite loops.
>
> --
> Frank
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