Index: uspace/drv/bus/isa/i8237.c
===================================================================
--- uspace/drv/bus/isa/i8237.c	(revision 1ec394e1b85d3ac70c0b5a99aebcdc0acdaa9b6f)
+++ uspace/drv/bus/isa/i8237.c	(revision f6992dfcf86bf7c23550d57afc78b3d6d4a5ca30)
@@ -338,4 +338,8 @@
 	if ((channel > 0) && (channel < 4) && (pa >= (1 << 20)))
 		return EINVAL;
+
+	/* Buffers cannot cross 64K page boundaries */
+	if ((pa & 0xffff0000) !=  ((pa + size) & 0xffff0000))
+		return EINVAL;
 	
 	fibril_mutex_lock(&guard);