avcodec/notchlc: Check uncompressed size against input for LZ4

Fixes: OOM
Fixes: 26168/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_NOTCHLC_fuzzer-6019839015256064
Equation is based on LZ4_COMPRESSBOUND from lz4.h
Suggested-by: Paul
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/notchlc.c b/libavcodec/notchlc.c
index 3f7079da7057a11f328509ff329b5be28627182c..d13ce3193c928acb61c719a0c20ee9e40a7ee4bf 100644 (file)
--- a/libavcodec/notchlc.c
+++ b/libavcodec/notchlc.c
@@ -490,6 +490,11 @@ static int decode_frame(AVCodecContext *avctx,
 
         bytestream2_init(gb, s->lzf_buffer, uncompressed_size);
     } else if (s->format == 1) {
+        unsigned remaining = bytestream2_get_bytes_left(gb);
+
+        if (remaining > 0x7E000000U || remaining + remaining/255 + 16 < uncompressed_size)
+            return AVERROR_INVALIDDATA;
+
         av_fast_padded_malloc(&s->uncompressed_buffer, &s->uncompressed_size,
                               uncompressed_size);
         if (!s->uncompressed_buffer)