[FFmpeg-devel] [PATCH v3] avformat/mxfdec: Remove this_partition

[Michael Niedermayer]

Hi

On Wed, Sep 27, 2023 at 01:37:40PM +0200, Tomas Härdin wrote:
> fre 2023-09-22 klockan 21:13 +0200 skrev Michael Niedermayer:
> > Suggested-by: Tomas Härdin <git at haerdin.se>
> > Fixes: 51896/clusterfuzz-testcase-minimized-ffmpeg_dem_MXF_fuzzer-
> > 5130394286817280
> > 
> > Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> > ---
> >  libavformat/mxfdec.c | 28 ++++++++++++++++++----------
> >  1 file changed, 18 insertions(+), 10 deletions(-)
> > 
> > diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
> > index 4846c5d206a..1313f14fa03 100644
> > --- a/libavformat/mxfdec.c
> > +++ b/libavformat/mxfdec.c
> > @@ -102,7 +102,6 @@ typedef struct MXFPartition {
> >      uint64_t previous_partition;
> >      int index_sid;
> >      int body_sid;
> > -    int64_t this_partition;
> >      int64_t essence_offset;         ///< absolute offset of essence
> >      int64_t essence_length;
> >      int32_t kag_size;
> > @@ -727,10 +726,13 @@ static int mxf_read_partition_pack(void *arg,
> > AVIOContext *pb, int tag, int size
> >      UID op;
> >      uint64_t footer_partition;
> >      uint32_t nb_essence_containers;
> > +    uint64_t this_partition;
> >  
> >      if (mxf->partitions_count >= INT_MAX / 2)
> >          return AVERROR_INVALIDDATA;
> >  
> > +    av_assert0(klv_offset >= mxf->run_in);
> > +
> >      tmp_part = av_realloc_array(mxf->partitions, mxf-
> > >partitions_count + 1, sizeof(*mxf->partitions));
> >      if (!tmp_part)
> >          return AVERROR(ENOMEM);
> > @@ -773,7 +775,13 @@ static int mxf_read_partition_pack(void *arg,
> > AVIOContext *pb, int tag, int size
> >      partition->complete = uid[14] > 2;
> >      avio_skip(pb, 4);
> >      partition->kag_size = avio_rb32(pb);
> > -    partition->this_partition = avio_rb64(pb);
> > +    this_partition = avio_rb64(pb);
> > +    if (this_partition != klv_offset - mxf->run_in) {
> > +        av_log(mxf->fc, AV_LOG_WARNING,
> > +               "this_partition %"PRId64" mismatches %"PRId64"\n",
> > +               this_partition, klv_offset - mxf->run_in);
> 
> We might want to error out here, since this means offsets are likely to
> be incorrect across the entire file. We have no files in FATE that
> demonstrate this problem, and it pays to be strict when it comes to
> MXF. This helps people writing new MXF muxers from writing broken ones.

ok, should i ask for a sample here (so we maybe get a sample)
or just error out with this message at AV_LOG_ERROR ?

thx

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

No great genius has ever existed without some touch of madness. -- Aristotle
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