--- linux/arch/i386/kernel/process.c	2004-04-14 09:41:14.000000000 +0400
+++ linux/arch/i386/kernel/process.c	2004-05-07 14:54:13.000000000 +0400
@@ -292,8 +292,12 @@
 
 	/* The process may have allocated an io port bitmap... nuke it. */
 	if (unlikely(NULL != tsk->thread.io_bitmap_ptr)) {
+		int cpu = get_cpu();
+		struct tss_struct *tss = init_tss + cpu;
 		kfree(tsk->thread.io_bitmap_ptr);
 		tsk->thread.io_bitmap_ptr = NULL;
+		tss->io_bitmap_base = INVALID_IO_BITMAP_OFFSET;
+		put_cpu();
 	}
 }