Index: mozilla/gfx/src/shared/gfxImageFrame.cpp
===================================================================
RCS file: /cvsroot/mozilla/gfx/src/shared/gfxImageFrame.cpp,v
retrieving revision 1.26
retrieving revision 1.26.12.1
diff -u -r1.26 -r1.26.12.1
--- gfx/src/shared/gfxImageFrame.cpp	16 Jan 2004 23:28:48 -0000	1.26
+++ gfx/src/shared/gfxImageFrame.cpp	27 Aug 2004 11:02:58 -0000	1.26.12.1
@@ -72,6 +72,13 @@
     return NS_ERROR_FAILURE;
   }
 
+  /* reject over-wide or over-tall images */
+  const PRInt32 k64KLimit = 0x0000FFFF;
+  if ( aWidth > k64KLimit || aHeight > k64KLimit ){
+    NS_ERROR("image too big");
+    return NS_ERROR_FAILURE;
+  }
+
   nsresult rv;
 
   mOffset.MoveTo(aX, aY);
Index: mozilla/gfx/src/windows/nsImageWin.cpp
===================================================================
RCS file: /cvsroot/mozilla/gfx/src/windows/nsImageWin.cpp,v
retrieving revision 3.130.2.1
retrieving revision 3.130.2.1.6.1
diff -u -r3.130.2.1 -r3.130.2.1.6.1
--- gfx/src/windows/nsImageWin.cpp	11 May 2004 21:53:49 -0000	3.130.2.1
+++ gfx/src/windows/nsImageWin.cpp	27 Aug 2004 11:02:58 -0000	3.130.2.1.6.1
@@ -131,6 +131,10 @@
     return NS_ERROR_UNEXPECTED;
   }
 
+  // limit images to 64k pixels on a side (~55 feet on a 100dpi monitor)
+  const PRInt32 k64KLimit = 0x0000FFFF;
+  if (aWidth > k64KLimit || aHeight > k64KLimit)
+      return NS_ERROR_FAILURE;
 
   if (mNumPaletteColors >= 0){
     // If we have a palette
Index: mozilla/modules/libpr0n/decoders/bmp/nsBMPDecoder.cpp
===================================================================
RCS file: /cvsroot/mozilla/modules/libpr0n/decoders/bmp/nsBMPDecoder.cpp,v
retrieving revision 1.24.2.1
retrieving revision 1.24.2.1.6.1
diff -u -r1.24.2.1 -r1.24.2.1.6.1
--- modules/libpr0n/decoders/bmp/nsBMPDecoder.cpp	13 May 2004 22:27:35 -0000	1.24.2.1
+++ modules/libpr0n/decoders/bmp/nsBMPDecoder.cpp	27 Aug 2004 11:02:58 -0000	1.24.2.1.6.1
@@ -274,7 +274,9 @@
             CalcBitShift();
         }
         // BMPs with negative width are invalid
-        if (mBIH.width < 0)
+        // Reject extremely wide images to keep the math sane
+        const PRInt32 k64KWidth = 0x0000FFFF;
+        if (mBIH.width < 0 || mBIH.width > k64KWidth)
             return NS_ERROR_FAILURE;
 
         PRUint32 real_height = (mBIH.height > 0) ? mBIH.height : -mBIH.height;