From 1493a952ed236c7339566a8cdd42d314fe3184e7 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michael@niedermayer.cc>
Date: Wed, 25 Sep 2019 01:07:34 +0200
Subject: [PATCH] avcodec/g729_parser: Check block_size

Fixes: Infinite loop
Fixes: 17611/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ACELP_KELVIN_fuzzer-5765134928052224

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 972a0a818ff7a9b33c7f37e08783f4b6082f9aa2)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavcodec/g729_parser.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libavcodec/g729_parser.c b/libavcodec/g729_parser.c
index 9982dbfffc..fc00235d7f 100644
--- a/libavcodec/g729_parser.c
+++ b/libavcodec/g729_parser.c
@@ -52,6 +52,12 @@ static int g729_parse(AVCodecParserContext *s1, AVCodecContext *avctx,
         s->duration   = avctx->frame_size;
     }
 
+    if (!s->block_size) {
+        *poutbuf      = buf;
+        *poutbuf_size = buf_size;
+        return buf_size;
+    }
+
     if (!s->remaining)
         s->remaining = s->block_size;
     if (s->remaining <= buf_size) {