On Mon, Jul 27, 2020 at 3:16 AM Michael Niedermayer <mich...@niedermayer.cc> wrote: > > Fixes: division by zero > Fixes: > 24201/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_JPEG2000_fuzzer-5665813827420160 > Fixes: > 24245/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_JPEG2000_fuzzer-6285831682392064 > > Found-by: continuous fuzzing process > https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg > Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> > --- > libavcodec/jpeg2000dec.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c > index a470cf47da..b168e52db6 100644 > --- a/libavcodec/jpeg2000dec.c > +++ b/libavcodec/jpeg2000dec.c > @@ -1401,12 +1401,12 @@ static int > jpeg2000_decode_packets_po_iteration(Jpeg2000DecoderContext *s, Jpeg2 > if (!s->cdx[compno] || !s->cdy[compno]) > return AVERROR_INVALIDDATA; > > - trx0 = ff_jpeg2000_ceildiv(tile->coord[0][0], > s->cdx[compno] << reducedresno); > - try0 = ff_jpeg2000_ceildiv(tile->coord[1][0], > s->cdy[compno] << reducedresno); > - > 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); > + > 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))))) > continue; > -- > 2.17.1 > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
Looks good to me. I guess the division by zero happens because shifting by reducedresno overflows? -- ------------- Gautam | _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
