[FFmpeg-devel] [PATCH 01/11] libavformat/mxfdec.c: klv_read_packet: Properly check klv_decode_ber_length return value.

[Alexis Ballier]

On Wed, 21 Oct 2015 23:31:29 +0200
Tomas Härdin <tomas.hardin at codemill.se> wrote:

> On Wed, 2015-10-21 at 18:00 +0200, Alexis Ballier wrote:
> > klv_decode_ber_length cannot return -1, but can return
> > AVERROR_INVALIDDATA. Store its return value in a signed integer
> > (instead of unsigned KLVPacket.length) and forward the error
> > appropriately. --- libavformat/mxfdec.c | 6 ++++--
> >  1 file changed, 4 insertions(+), 2 deletions(-)
> > 
> > diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
> > index 00d420b..94a953b 100644
> > --- a/libavformat/mxfdec.c
> > +++ b/libavformat/mxfdec.c
> > @@ -366,13 +366,15 @@ static int mxf_read_sync(AVIOContext *pb,
> > const uint8_t *key, unsigned size) 
> >  static int klv_read_packet(KLVPacket *klv, AVIOContext *pb)
> >  {
> > +    int64_t len;
> >      if (!mxf_read_sync(pb, mxf_klv_key, 4))
> >          return AVERROR_INVALIDDATA;
> >      klv->offset = avio_tell(pb) - 4;
> >      memcpy(klv->key, mxf_klv_key, 4);
> >      avio_read(pb, klv->key + 4, 12);
> > -    klv->length = klv_decode_ber_length(pb);
> > -    return klv->length == -1 ? -1 : 0;
> > +    len = klv_decode_ber_length(pb);
> > +    klv->length = FFMAX(len, 0);
> > +    return FFMIN(len, 0);
> >  }  
> 
> Can't klv_read_packet() return int64_t instead?

you mean change the return type and return klv->length ?
that might work, but note that what I'm trying to fix is
klv_read_packet setting length to (unsigned)AVERROR_INVALIDDATA, i.e.,
something close to 2^64, and returning 0.
I don't see any problem by doing that, so it is as you prefer.