File CVE-2018-19873.patch of Package A_tw-libqt4

Author:     Eirik Aavitsland <eirik.aavitsland@qt.io>
AuthorDate: 2018-09-04 11:08:06 +0200
Commit:     Eirik Aavitsland <eirik.aavitsland@qt.io>
CommitDate: 2018-09-11 06:36:34 +0000

bmp image handler: check for out of range image size

Make the decoder fail early to avoid spending time and memory on
attempting to decode a corrupt image file.

Change-Id: I874e04f3b43122d73f8e58c7a5bcc4a741b68264
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

--- qt-everywhere-opensource-src-4.8.7.orig/src/gui/image/qbmphandler.cpp
+++ qt-everywhere-opensource-src-4.8.7/src/gui/image/qbmphandler.cpp
@@ -181,6 +181,8 @@ static bool read_dib_infoheader(QDataStr
     if (!(comp == BMP_RGB || (nbits == 4 && comp == BMP_RLE4) ||
         (nbits == 8 && comp == BMP_RLE8) || ((nbits == 16 || nbits == 32) && comp == BMP_BITFIELDS)))
          return false;                                // weird compression type
+    if (bi.biWidth < 0 || quint64(bi.biWidth) * qAbs(bi.biHeight) > 16384 * 16384)
+        return false;
 
     return true;
 }