From c3ef24d9baf63f8c8794dfb2ef7192a64b586526 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michael@niedermayer.cc>
Date: Sat, 13 Jul 2019 19:57:21 +0200
Subject: [PATCH] avformat/vividas: Check buffer size before allocation

Fixes: out of array access
Fixes: 15365/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-5716153105645568

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavformat/vividas.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavformat/vividas.c b/libavformat/vividas.c
index c0d39f0a6f..184d24f374 100644
--- a/libavformat/vividas.c
+++ b/libavformat/vividas.c
@@ -251,6 +251,9 @@ static uint8_t *read_sb_block(AVIOContext *src, unsigned *size,
         *key = tmpkey;
     }
 
+    if (n < 8)
+        return NULL;
+
     buf = av_malloc(n);
     if (!buf)
         return NULL;