Index: svgalib-1.4.3/src/fbdev.c
===================================================================
--- svgalib-1.4.3.orig/src/fbdev.c	2011-01-06 14:24:59.000000000 +0100
+++ svgalib-1.4.3/src/fbdev.c	2011-01-06 14:27:39.000000000 +0100
@@ -141,9 +141,17 @@
 	if (page != oldpage)
 	{
 //		munmap(BANKED_MEM_POINTER, __svgalib_banked_mem_size);
-		mmap(BANKED_MEM_POINTER, __svgalib_banked_mem_size,
+		long size = __svgalib_banked_mem_size;
+		long offs = page * __svgalib_banked_mem_size;
+		if (size + offs > __svgalib_linear_mem_size)
+		   size = __svgalib_linear_mem_size - offs;
+		if (size <= 0) {
+		   fprintf (stderr, "invalid page %i requested", page);
+		}
+
+		mmap(BANKED_MEM_POINTER, size,
 		     PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED,
-		     fbdev_fd, page * __svgalib_banked_mem_size);
+		     fbdev_fd, offs);
 		oldpage = page;
 	}
 }