From 493dc7bb12ab0cc503fc81a6a3a86df6a7cee676 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michael@niedermayer.cc>
Date: Mon, 8 May 2017 15:17:31 +0200
Subject: [PATCH] avcodec/dvbsubdec: check region dimensions

Fixes: 1408/clusterfuzz-testcase-minimized-6529985844084736
Fixes: integer overflow

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 0075d9eced22839fa4f7a6eaa02155803ccae3e6)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavcodec/dvbsubdec.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/libavcodec/dvbsubdec.c b/libavcodec/dvbsubdec.c
index 097597ed91..b56103f899 100644
--- a/libavcodec/dvbsubdec.c
+++ b/libavcodec/dvbsubdec.c
@@ -23,6 +23,7 @@
 #include "get_bits.h"
 #include "bytestream.h"
 #include "libavutil/colorspace.h"
+#include "libavutil/imgutils.h"
 #include "libavutil/opt.h"
 
 #define DVBSUB_PAGE_SEGMENT     0x10
@@ -1138,6 +1139,7 @@ static void dvbsub_parse_region_segment(AVCodecContext *avctx,
     DVBSubObject *object;
     DVBSubObjectDisplay *display;
     int fill;
+    int ret;
 
     if (buf_size < 10)
         return;
@@ -1164,6 +1166,12 @@ static void dvbsub_parse_region_segment(AVCodecContext *avctx,
     region->height = AV_RB16(buf);
     buf += 2;
 
+    ret = av_image_check_size(region->width, region->height, 0, avctx);
+    if (ret < 0) {
+        region->width= region->height= 0;
+        return;
+    }
+
     if (region->width * region->height != region->buf_size) {
         av_free(region->pbuf);