[FFmpeg-devel] [PATCH 5/5] avcodec/mpeg4videodec: Check bps (VOL header) before VOP for studio profile

[Michael Niedermayer]

Fixes: runtime error: shift exponent -1 is negative
Fixes: 7486/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MPEG4_fuzzer-4977380939530240

Fixes: runtime error: index 36 out of bounds for type 'const uint8_t [32]'
Fixes: 7566/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MPEG4_fuzzer-6536620682510336

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/mpeg4videodec.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/libavcodec/mpeg4videodec.c b/libavcodec/mpeg4videodec.c
index 33cdc7a1b2..ada5cdc6fa 100644
--- a/libavcodec/mpeg4videodec.c
+++ b/libavcodec/mpeg4videodec.c
@@ -3217,9 +3217,13 @@ end:
         s->low_delay = 1;
     s->avctx->has_b_frames = !s->low_delay;
 
-    if (s->studio_profile)
+    if (s->studio_profile) {
+        if (!s->avctx->bits_per_raw_sample) {
+            av_log(s->avctx, AV_LOG_ERROR, "Missing VOL header\n");
+            return AVERROR_INVALIDDATA;
+        }
         return decode_studio_vop_header(ctx, gb);
-    else
+    } else
         return decode_vop_header(ctx, gb);
 }
 
-- 
2.17.0