[FFmpeg-cvslog] avcodec/qdm2: Check checksum_size for 0

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Mon Jun 24 01:01:04 2019 +0200| [7b2ebf89a411d957ca999f1e7a919ff617fbfd56] | committer: Michael Niedermayer

avcodec/qdm2: Check checksum_size for 0

Fixes: Infinite loop
Fixes: 15337/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_QDM2_fuzzer-5757428949319680

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=7b2ebf89a411d957ca999f1e7a919ff617fbfd56
---

 libavcodec/qdm2.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavcodec/qdm2.c b/libavcodec/qdm2.c
index 1e91f477e8..eaffb36dcc 100644
--- a/libavcodec/qdm2.c
+++ b/libavcodec/qdm2.c
@@ -1704,8 +1704,8 @@ static av_cold int qdm2_decode_init(AVCodecContext *avctx)
     s->group_size = bytestream2_get_be32(&gb);
     s->fft_size = bytestream2_get_be32(&gb);
     s->checksum_size = bytestream2_get_be32(&gb);
-    if (s->checksum_size >= 1U << 28) {
-        av_log(avctx, AV_LOG_ERROR, "data block size too large (%u)\n", s->checksum_size);
+    if (s->checksum_size >= 1U << 28 || !s->checksum_size) {
+        av_log(avctx, AV_LOG_ERROR, "data block size invalid (%u)\n", s->checksum_size);
         return AVERROR_INVALIDDATA;
     }