avcodec/rasc: Check input size in decode_fint()

Fixes: Timeout (11sec -> 42ms)
Fixes: 18287/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_RASC_fuzzer-5637866331308032
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/rasc.c b/libavcodec/rasc.c
index 21fc43f325c761a8f0fec0cd5b87d9baaa75f9e4..cdf20a6db9a55d7804687f28af4084a152f13e1b 100644 (file)
--- a/libavcodec/rasc.c
+++ b/libavcodec/rasc.c
@@ -124,6 +124,8 @@ static int decode_fint(AVCodecContext *avctx,
         clear_plane(avctx, s->frame1);
         return 0;
     }
+    if (bytestream2_get_bytes_left(gb) < 72)
+        return AVERROR_INVALIDDATA;
 
     bytestream2_skip(gb, 8);
     w = bytestream2_get_le32(gb);