avcodec/mpeg4videodec: Check bps (VOL header) before VOP for studio profile
authorMichael Niedermayer <michael@niedermayer.cc>
Sun, 29 Apr 2018 18:28:46 +0000 (20:28 +0200)
committerMichael Niedermayer <michael@niedermayer.cc>
Thu, 17 May 2018 00:23:06 +0000 (02:23 +0200)
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@niedermayer.cc>
libavcodec/mpeg4videodec.c

index 33cdc7a..ada5cdc 100644 (file)
@@ -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);
 }