[FFmpeg-cvslog] avcodec/hevc_mp4toannexb_bsf: Check nalu_size

[Michael Niedermayer]

ffmpeg | branch: release/2.8 | Michael Niedermayer <michael at niedermayer.cc> | Sun Apr 19 18:24:55 2020 +0200| [a1c51c0713c11769bc64110e337a397b71df4f40] | committer: Michael Niedermayer

avcodec/hevc_mp4toannexb_bsf: Check nalu_size

Fixes: Timeout (29sec -> 5ms)
Fixes: 20237/clusterfuzz-testcase-minimized-ffmpeg_BSF_HEVC_MP4TOANNEXB_fuzzer-5165615044362240

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit ae2537f53e8ebfa36345241b5b70c0b1aef66dd2)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=a1c51c0713c11769bc64110e337a397b71df4f40
---

 libavcodec/hevc_mp4toannexb_bsf.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/libavcodec/hevc_mp4toannexb_bsf.c b/libavcodec/hevc_mp4toannexb_bsf.c
index 93fc5ed650..bcf845d688 100644
--- a/libavcodec/hevc_mp4toannexb_bsf.c
+++ b/libavcodec/hevc_mp4toannexb_bsf.c
@@ -161,6 +161,11 @@ static int hevc_mp4toannexb_filter(AVBitStreamFilterContext *bsfc,
         for (i = 0; i < ctx->length_size; i++)
             nalu_size = (nalu_size << 8) | bytestream2_get_byte(&gb);
 
+        if (nalu_size < 2) {
+            ret = AVERROR_INVALIDDATA;
+            goto fail;
+        }
+
         nalu_type = (bytestream2_peek_byte(&gb) >> 1) & 0x3f;
 
         /* prepend extradata to IRAP frames */