From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753944Ab3AGJCZ (ORCPT ); Mon, 7 Jan 2013 04:02:25 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:27496 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753688Ab3AGJCW (ORCPT ); Mon, 7 Jan 2013 04:02:22 -0500 Date: Mon, 7 Jan 2013 12:02:10 +0300 From: Dan Carpenter To: masa-korg@dsn.okisemi.com Cc: Arnd Bergmann , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Tomoya MORINAGA Subject: re: add Packet hub driver for Topcliff Platform controller hub Message-ID: <20130107090210.GA20716@elgon.mountain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: ucsinet22.oracle.com [156.151.31.94] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Masayuki Ohtak, The patch cf4ece53460c: "add Packet hub driver for Topcliff Platform controller hub" from Sep 1, 2010, leads to the following warning: drivers/misc/pch_phub.c:596 pch_phub_bin_write() error: buffer overflow 'buf' 4096 <= 15359 Sorry my question is about an old patch. Smatch complains because we only pass a PAGE_SIZE buffer to sysfs files so the test for "if (count > PCH_PHUB_OROM_SIZE) {" makes it think we are overflowing. In fact, count is never more than 4096 so there is no overflow, but I also think that it means only the first 4096 bytes of the firmware gets updated. drivers/misc/pch_phub.c 560 static ssize_t pch_phub_bin_write(struct file *filp, struct kobject *kobj, 561 struct bin_attribute *attr, 562 char *buf, loff_t off, size_t count) 563 { 564 int err; 565 unsigned int addr_offset; 566 int ret; 567 ssize_t rom_size; 568 struct pch_phub_reg *chip = 569 dev_get_drvdata(container_of(kobj, struct device, kobj)); 570 571 ret = mutex_lock_interruptible(&pch_phub_mutex); 572 if (ret) 573 return -ERESTARTSYS; 574 575 if (off > PCH_PHUB_OROM_SIZE) { 576 addr_offset = 0; 577 goto return_ok; 578 } 579 if (count > PCH_PHUB_OROM_SIZE) { ^^^^^^^^^^^^^^^^^^ This is 15359. 580 addr_offset = 0; 581 goto return_ok; 582 } 583 584 chip->pch_phub_extrom_base_address = pci_map_rom(chip->pdev, &rom_size); 585 if (!chip->pch_phub_extrom_base_address) { 586 err = -ENOMEM; 587 goto exrom_map_err; 588 } 589 590 for (addr_offset = 0; addr_offset < count; addr_offset++) { 591 if (PCH_PHUB_OROM_SIZE < off + addr_offset) 592 goto return_ok; 593 594 ret = pch_phub_write_serial_rom(chip, 595 chip->pch_opt_rom_start_address + addr_offset + off, 596 buf[addr_offset]); ^^^^^^^^^^^^^^^^ Smatch complains because "buf" is only 4096 bytes. regards, dan carpenter