avcodec/ituh263dec: Make the condition for the studio slice start code match between...
authorMichael Niedermayer <michael@niedermayer.cc>
Sat, 14 Sep 2019 16:31:40 +0000 (18:31 +0200)
committerMichael Niedermayer <michael@niedermayer.cc>
Sat, 28 Sep 2019 16:35:27 +0000 (18:35 +0200)
If they mismatch an infinite loop can occur
Fixes: Timeout (infinite loop)
Fixes: 17043/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MPEG4_fuzzer-5695051748868096

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
libavcodec/ituh263dec.c

index afc786b..c37f872 100644 (file)
@@ -222,7 +222,7 @@ int ff_h263_resync(MpegEncContext *s){
             get_bits(&s->gb, 8);
         }
 
-        if (show_bits_long(&s->gb, 32) == SLICE_START_CODE)
+        if (get_bits_left(&s->gb) >= 32 && show_bits_long(&s->gb, 32) == SLICE_START_CODE)
             return get_bits_count(&s->gb);
         else
             return -1;