From 697160366fd101898ef0caeac96234a64137eaad Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michael@niedermayer.cc>
Date: Mon, 13 Jul 2015 19:10:59 +0200
Subject: [PATCH] avcodec/vp3: check current_frame before accessing it
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Fixes null pointer dereference
Fixes: b15eb06e0111e94bc59123c86db7aff9_signal_sigsegv_a0500f_45_320vp3.nsv with allocation limit  536870912

Found-by: Samuel Groß, Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavcodec/vp3.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libavcodec/vp3.c b/libavcodec/vp3.c
index 005f043b0f..2492026cb6 100644
--- a/libavcodec/vp3.c
+++ b/libavcodec/vp3.c
@@ -1947,6 +1947,8 @@ static int vp3_update_thread_context(AVCodecContext *dst, const AVCodecContext *
     }
 
     if (s != s1) {
+        if (!s->current_frame.f)
+            return AVERROR(ENOMEM);
         // init tables if the first frame hasn't been decoded
         if (!s->current_frame.f->data[0]) {
             int y_fragment_count, c_fragment_count;