From 18e17d3a7a6f2b2835638b1e963b7adb458a309b Mon Sep 17 00:00:00 2001
From: Albert Astals Cid <aacid@kde.org>
Date: Tue, 29 Jan 2019 12:39:52 +0100
Subject: [PATCH] tga: Don't support more than 8 alpha bits

Fixes undefined left shift with negative values

oss-fuzz/12764
---
 src/imageformats/tga.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/imageformats/tga.cpp b/src/imageformats/tga.cpp
index 9217bed..2ca9d1d 100644
--- a/src/imageformats/tga.cpp
+++ b/src/imageformats/tga.cpp
@@ -186,6 +186,10 @@ static bool LoadTGA(QDataStream &s, const TgaHeader &tga, QImage &img)
     // However alpha exists only in the 32 bit format.
     if ((tga.pixel_size == 32) && (tga.flags & 0xf)) {
         img = QImage(tga.width, tga.height, QImage::Format_ARGB32);
+
+        if (numAlphaBits > 8) {
+            return false;
+        }
     }
 
     uint pixel_size = (tga.pixel_size / 8);