[FFmpeg-cvslog] avcodec/rasc: Check frame before clearing

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Thu Dec  3 23:41:10 2020 +0100| [380a3a0adfae7aa898d2ec8a5b0d5cd949a11111] | committer: Michael Niedermayer

avcodec/rasc: Check frame before clearing

Fixes: null pointer dereference
Fixes: 27737/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_RASC_fuzzer-5769028685266944

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=380a3a0adfae7aa898d2ec8a5b0d5cd949a11111
---

 libavcodec/rasc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavcodec/rasc.c b/libavcodec/rasc.c
index cdf20a6db9..706940bf5f 100644
--- a/libavcodec/rasc.c
+++ b/libavcodec/rasc.c
@@ -70,6 +70,9 @@ static void clear_plane(AVCodecContext *avctx, AVFrame *frame)
     RASCContext *s = avctx->priv_data;
     uint8_t *dst = frame->data[0];
 
+    if (!dst)
+        return;
+
     for (int y = 0; y < avctx->height; y++) {
         memset(dst, 0, avctx->width * s->bpp);
         dst += frame->linesize[0];