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@niedermayer.cc>

diff --git a/libavcodec/qdm2.c b/libavcodec/qdm2.c
index 1e91f477e8f12aa2241edc708a3a865b23d07a34..eaffb36dcc08a879be32b950df19a9181e825d34 100644 (file)
--- 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;
     }