Re: [FFmpeg-devel] [PATCH 2/4] avformat/mxfdec: Check count in mxf_read_strong_ref_array()

["Tomas Härdin" <tjoppen@acc.umu.se>]

sön 2022-03-20 klockan 15:06 +0100 skrev Michael Niedermayer:
> On Sun, Mar 20, 2022 at 02:05:41PM +0100, Tomas Härdin wrote:
> > lör 2022-03-19 klockan 23:50 +0100 skrev Michael Niedermayer:
> [...]
> > > 
> > > 
> > > > 
> > > > > +
> > > > > +    //avio_read() used int
> > > > > +    if (c > INT_MAX / sizeof(UID))
> > > > > +        return AVERROR_PATCHWELCOME;
> > > > > +    *count = c;
> > > > > +
> > > > 
> > > > This should already be caught by av_calloc(), no?
> > > 
> > > the API as in the documentation of av_calloc() does not gurantee
> > > this. 
> > 
> > Yes it does:
> > 
> >   The allocated memory will have size `size * nmemb` bytes.
> >   [...]
> >   `NULL` if the block cannot be allocated
> 
> void *av_calloc(size_t nmemb, size_t size)
> size_t can be larger than int, so size * nmemb may be larger than
> INT_MAX

Crap, you're right. This also brings to mind the question why
packages_count etc are int rather than unsigned or uint32_t..

Patch is OK then

/Tomas

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