[FFmpeg-cvslog] avcodec/notchlc: Check uncompressed size against input for LZ4

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Tue Oct 13 22:44:21 2020 +0200| [51002362c4ed301e54cea1597666cd5cc9a134f3] | committer: Michael Niedermayer

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 at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=51002362c4ed301e54cea1597666cd5cc9a134f3
---

 libavcodec/notchlc.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/libavcodec/notchlc.c b/libavcodec/notchlc.c
index 3f7079da70..d13ce3193c 100644
--- 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)