diff -urNp x-ref/mm/filemap.c x/mm/filemap.c
--- x-ref/mm/filemap.c	2003-01-14 02:59:26.000000000 +0100
+++ x/mm/filemap.c	2003-01-14 03:00:14.000000000 +0100
@@ -1571,7 +1571,7 @@ static ssize_t generic_file_direct_IO(in
 	chunk_size = KIO_MAX_ATOMIC_IO << 10;
 
 	retval = -EINVAL;
-	if ((offset & blocksize_mask) || (count & blocksize_mask))
+	if ((offset & blocksize_mask) || (count & blocksize_mask) || ((unsigned long) buf & blocksize_mask))
 		goto out_free;
 	if (!mapping->a_ops->direct_IO)
 		goto out_free;