Fix Crash: Loading Huge Images.

When loading huge images (30k) blender crashed with a buffer overflow.
The reason is that determine the length of a buffer was done in 32bit
precision and afterwards stored in 64 bit precision.

This patch adds a new function to do the correct calculation in 64bit.
It should be added to other sections in blender as well. But that should
be tested on a per case situation.

1 files changed, 11 insertions, 0 deletions

diff --git a/source/blender/imbuf/IMB_imbuf.h b/source/blender/imbuf/IMB_imbuf.h
index 6e8bed148d5..daa3dbd1f1a 100644
--- a/source/blender/imbuf/IMB_imbuf.h
+++ b/source/blender/imbuf/IMB_imbuf.h
@@ -201,6 +201,17 @@ bool addzbuffloatImBuf(struct ImBuf *ibuf);
 size_t IMB_get_size_in_memory(struct ImBuf *ibuf);
 
 /**
+ * \brief Get the length of the rect of the given image buffer in terms of pixels.
+ *
+ * This is the width * the height of the image buffer.
+ * This function is preferred over `ibuf->x * ibuf->y` due to overflow issues when
+ * working with large resolution images (30kx30k).
+ *
+ * \attention Defined in allocimbuf.c
+ */
+size_t IMB_get_rect_len(const struct ImBuf *ibuf);
+
+/**
  *
  * \attention Defined in rectop.c
  */