[FFmpeg-devel] [PATCH 1/2] avcodec/jpeg2000dec: Handle reducedresno of 32

[Gautam Ramakrishnan]

On Wed, Aug 5, 2020 at 8:43 PM Michael Niedermayer
<michael at niedermayer.cc> wrote:
>
> Fixes: shift exponent 32 is too large for 32-bit type 'int'
> Fixes: 24566/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_JPEG2000_fuzzer-6033783737024512
>
> 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/jpeg2000.h    |  4 ++--
>  libavcodec/jpeg2000dec.c | 24 ++++++++++++------------
>  2 files changed, 14 insertions(+), 14 deletions(-)
>
> diff --git a/libavcodec/jpeg2000.h b/libavcodec/jpeg2000.h
> index 27df43786d..5b0627c3dc 100644
> --- a/libavcodec/jpeg2000.h
> +++ b/libavcodec/jpeg2000.h
> @@ -220,9 +220,9 @@ static inline int ff_jpeg2000_ceildivpow2(int a, int b)
>      return -((-(int64_t)a) >> b);
>  }
>
> -static inline int ff_jpeg2000_ceildiv(int a, int b)
> +static inline int ff_jpeg2000_ceildiv(int a, int64_t b)
>  {
> -    return (a + (int64_t)b - 1) / b;
> +    return (a + b - 1) / b;
>  }
>
>  /* TIER-1 routines */
> diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c
> index dcebe97272..624542c2f8 100644
> --- a/libavcodec/jpeg2000dec.c
> +++ b/libavcodec/jpeg2000dec.c
> @@ -1465,20 +1465,20 @@ static int jpeg2000_decode_packets_po_iteration(Jpeg2000DecoderContext *s, Jpeg2
>                          if (reslevelno >= codsty->nreslevels)
>                              continue;
>
> -                        trx0 = ff_jpeg2000_ceildiv(tile->coord[0][0], s->cdx[compno] << reducedresno);
> -                        try0 = ff_jpeg2000_ceildiv(tile->coord[1][0], s->cdy[compno] << reducedresno);
> +                        trx0 = ff_jpeg2000_ceildiv(tile->coord[0][0], (int64_t)s->cdx[compno] << reducedresno);
> +                        try0 = ff_jpeg2000_ceildiv(tile->coord[1][0], (int64_t)s->cdy[compno] << reducedresno);
>
>                          if (!(y % ((uint64_t)s->cdy[compno] << (rlevel->log2_prec_height + reducedresno)) == 0 ||
> -                             (y == tile->coord[1][0] && (try0 << reducedresno) % (1U << (reducedresno + rlevel->log2_prec_height)))))
> +                             (y == tile->coord[1][0] && ((int64_t)try0 << reducedresno) % (1ULL << (reducedresno + rlevel->log2_prec_height)))))
>                              continue;
>
>                          if (!(x % ((uint64_t)s->cdx[compno] << (rlevel->log2_prec_width + reducedresno)) == 0 ||
> -                             (x == tile->coord[0][0] && (trx0 << reducedresno) % (1U << (reducedresno + rlevel->log2_prec_width)))))
> +                             (x == tile->coord[0][0] && ((int64_t)trx0 << reducedresno) % (1ULL << (reducedresno + rlevel->log2_prec_width)))))
>                              continue;
>
>                          // check if a precinct exists
> -                        prcx   = ff_jpeg2000_ceildiv(x, s->cdx[compno] << reducedresno) >> rlevel->log2_prec_width;
> -                        prcy   = ff_jpeg2000_ceildiv(y, s->cdy[compno] << reducedresno) >> rlevel->log2_prec_height;
> +                        prcx   = ff_jpeg2000_ceildiv(x, (int64_t)s->cdx[compno] << reducedresno) >> rlevel->log2_prec_width;
> +                        prcy   = ff_jpeg2000_ceildiv(y, (int64_t)s->cdy[compno] << reducedresno) >> rlevel->log2_prec_height;
>                          prcx  -= ff_jpeg2000_ceildivpow2(comp->coord_o[0][0], reducedresno) >> rlevel->log2_prec_width;
>                          prcy  -= ff_jpeg2000_ceildivpow2(comp->coord_o[1][0], reducedresno) >> rlevel->log2_prec_height;
>
> @@ -1543,20 +1543,20 @@ static int jpeg2000_decode_packets_po_iteration(Jpeg2000DecoderContext *s, Jpeg2
>                          Jpeg2000ResLevel *rlevel = comp->reslevel + reslevelno;
>                          int trx0, try0;
>
> -                        trx0 = ff_jpeg2000_ceildiv(tile->coord[0][0], s->cdx[compno] << reducedresno);
> -                        try0 = ff_jpeg2000_ceildiv(tile->coord[1][0], s->cdy[compno] << reducedresno);
> +                        trx0 = ff_jpeg2000_ceildiv(tile->coord[0][0], (int64_t)s->cdx[compno] << reducedresno);
> +                        try0 = ff_jpeg2000_ceildiv(tile->coord[1][0], (int64_t)s->cdy[compno] << reducedresno);
>
>                          if (!(y % ((uint64_t)s->cdy[compno] << (rlevel->log2_prec_height + reducedresno)) == 0 ||
> -                             (y == tile->coord[1][0] && (try0 << reducedresno) % (1U << (reducedresno + rlevel->log2_prec_height)))))
> +                             (y == tile->coord[1][0] && ((int64_t)try0 << reducedresno) % (1ULL << (reducedresno + rlevel->log2_prec_height)))))
>                               continue;
>
>                          if (!(x % ((uint64_t)s->cdx[compno] << (rlevel->log2_prec_width + reducedresno)) == 0 ||
> -                             (x == tile->coord[0][0] && (trx0 << reducedresno) % (1U << (reducedresno + rlevel->log2_prec_width)))))
> +                             (x == tile->coord[0][0] && ((int64_t)trx0 << reducedresno) % (1ULL << (reducedresno + rlevel->log2_prec_width)))))
>                               continue;
>
>                          // check if a precinct exists
> -                        prcx   = ff_jpeg2000_ceildiv(x, s->cdx[compno] << reducedresno) >> rlevel->log2_prec_width;
> -                        prcy   = ff_jpeg2000_ceildiv(y, s->cdy[compno] << reducedresno) >> rlevel->log2_prec_height;
> +                        prcx   = ff_jpeg2000_ceildiv(x, (int64_t)s->cdx[compno] << reducedresno) >> rlevel->log2_prec_width;
> +                        prcy   = ff_jpeg2000_ceildiv(y, (int64_t)s->cdy[compno] << reducedresno) >> rlevel->log2_prec_height;
>                          prcx  -= ff_jpeg2000_ceildivpow2(comp->coord_o[0][0], reducedresno) >> rlevel->log2_prec_width;
>                          prcy  -= ff_jpeg2000_ceildivpow2(comp->coord_o[1][0], reducedresno) >> rlevel->log2_prec_height;
>
> --
> 2.17.1
>
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Looks Good to Me

-- 
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Gautam |