From: Derek Buitenhuis <derek.buitenhuis@gmail.com>
Date: Mon, 15 Dec 2014 22:59:08 +0000 (-0500)
Subject: snow_dwt: Don't try and free members of non-existent arrays
X-Git-Tag: android-x86-6.0-r1~1392
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=402a61c9197b6d1199e3f12c41a99924b5811cfe;p=android-x86%2Fexternal-ffmpeg.git

snow_dwt: Don't try and free members of non-existent arrays

If allocation fails earlier on, and the next frame is processed,
the slice buffer could be left in a state where line and data_stack
have already been freed, or are otherwise null pointers.

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
---

diff --git a/libavcodec/snow_dwt.c b/libavcodec/snow_dwt.c
index 5b890e01b5..986a6b904c 100644
--- a/libavcodec/snow_dwt.c
+++ b/libavcodec/snow_dwt.c
@@ -91,6 +91,10 @@ void ff_slice_buffer_release(slice_buffer *buf, int line)
 void ff_slice_buffer_flush(slice_buffer *buf)
 {
     int i;
+
+    if (!buf->line)
+        return;
+
     for (i = 0; i < buf->line_count; i++)
         if (buf->line[i])
             ff_slice_buffer_release(buf, i);
@@ -101,8 +105,9 @@ void ff_slice_buffer_destroy(slice_buffer *buf)
     int i;
     ff_slice_buffer_flush(buf);
 
-    for (i = buf->data_count - 1; i >= 0; i--)
-        av_freep(&buf->data_stack[i]);
+    if (buf->data_stack)
+        for (i = buf->data_count - 1; i >= 0; i--)
+            av_freep(&buf->data_stack[i]);
     av_freep(&buf->data_stack);
     av_freep(&buf->line);
 }