From 6ea8f03bf4b7bca2f4db28ea57696584e2560e20 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 26 Jul 2020 19:41:30 +0200 Subject: [PATCH] avcodec/jpeg2000dec: Move reslevelno check before use in case JPEG2000_PGOD_RPCL 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 Reviewed-by: Gautam Ramakrishnan Signed-off-by: Michael Niedermayer --- 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;