missing copy_from_user check in mixcom driver.

diff -urpN --exclude-from=/home/davej/.exclude bk-linus/drivers/net/wan/comx-hw-mixcom.c linux-2.5/drivers/net/wan/comx-hw-mixcom.c
@@ -763,7 +763,10 @@ static int mixcom_write_proc(struct file
 		return -ENOMEM;
 	}
 
-	copy_from_user(page, buffer, count = min_t(unsigned long, count, PAGE_SIZE));
+	if (copy_from_user(page, buffer, count = min_t(unsigned long, count, PAGE_SIZE))) {
+		free_page((unsigned long)page);
+		return -EFAULT;
+	}
 	if (*(page + count - 1) == '\n') {
 		*(page + count - 1) = 0;
 	}