[FFmpeg-devel] [PATCH 1/3] avcodec/aacdec_template: Fix undefined integer overflow in apply_tns()

[Michael Niedermayer]

On Sun, Jul 02, 2017 at 01:33:16PM +0200, Michael Niedermayer wrote:
> On Sun, Jul 02, 2017 at 01:14:31PM +0200, wm4 wrote:
> > On Sun,  2 Jul 2017 04:28:54 +0200
> > Michael Niedermayer <michael at niedermayer.cc> wrote:
> > 
> > > Fixes: runtime error: signed integer overflow: -2147483648 - 1202286525 cannot be represented in type 'int'
> > > Fixes: 2071/clusterfuzz-testcase-minimized-6036414271586304
> > > 
> > > 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/aac_defines.h     | 2 ++
> > >  libavcodec/aacdec_template.c | 5 +++--
> > >  2 files changed, 5 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/libavcodec/aac_defines.h b/libavcodec/aac_defines.h
> > > index 3c79a8a4a1..ee4c73a87d 100644
> > > --- a/libavcodec/aac_defines.h
> > > +++ b/libavcodec/aac_defines.h
> > > @@ -35,6 +35,7 @@
> > >  #define AAC_RENAME(x)       x ## _fixed
> > >  #define AAC_RENAME_32(x)    x ## _fixed_32
> > >  typedef int                 INTFLOAT;
> > > +typedef unsigned            SUINTFLOAT;
> > >  typedef int64_t             INT64FLOAT;
> > >  typedef int16_t             SHORTFLOAT;
> > >  typedef SoftFloat           AAC_FLOAT;
> > > @@ -83,6 +84,7 @@ typedef int                 AAC_SIGNE;
> > >  #define AAC_RENAME(x)       x
> > >  #define AAC_RENAME_32(x)    x
> > >  typedef float               INTFLOAT;
> > > +typedef float               SUINTFLOAT;
> > 
> > Not more of this damn shit.
> 
> i dont think i understand your comment
> 
> The code is templated and uses largely the INTFLOAT data type
> which is either signed int or float depending on if the code is build
> for the fixed point or floating point decoder
> 
> to fix the undefined behavior in the fixed point decoder a type which
> is unsigned int is the obvious choice.
> Such type must be float in the floating point decoder.
> 
> This patch adds such type.
> 
> do you object to fixing the issue ?
> do you want to suggest a different solution ?

over a week passed, noone replied.
Is everyone ok with patch 1/3 ?
does someone object to it ?
does anyone have a better solution ?

If noone replies, i will apply this patch, i do not want to leave
undefined behavior in the codebase.

Thanks

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

It is dangerous to be right in matters on which the established authorities
are wrong. -- Voltaire
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 181 bytes
Desc: Digital signature
URL: <http://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20170711/c85ae5de/attachment.sig>