From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753953Ab2LBNzH (ORCPT ); Sun, 2 Dec 2012 08:55:07 -0500 Received: from mail-ee0-f46.google.com ([74.125.83.46]:49757 "EHLO mail-ee0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751441Ab2LBNzD (ORCPT ); Sun, 2 Dec 2012 08:55:03 -0500 From: Christian Lamparter To: Dan Carpenter Subject: Re: [patch] p54: potential signedness issue in p54_parse_rssical() Date: Sun, 2 Dec 2012 14:54:56 +0100 User-Agent: KMail/1.13.7 (Linux/3.7.0-rc5-wl+; KDE/4.8.4; x86_64; ; ) Cc: "John W. Linville" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org References: <20121202103609.GA16078@elgon.mountain> In-Reply-To: <20121202103609.GA16078@elgon.mountain> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201212021454.57147.chunkeey@googlemail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sunday 02 December 2012 11:36:09 Dan Carpenter wrote: > "entries" is unsigned here, so it is never less than zero. In theory, > len could be less than offset so I have added a check for that. > > Signed-off-by: Dan Carpenter Acked-by: Christian Lamparter > diff --git a/drivers/net/wireless/p54/eeprom.c b/drivers/net/wireless/p54/eeprom.c > index 1ef1bfe..d43e374 100644 > --- a/drivers/net/wireless/p54/eeprom.c > +++ b/drivers/net/wireless/p54/eeprom.c > @@ -541,8 +541,9 @@ static int p54_parse_rssical(struct ieee80211_hw *dev, > entries = (len - offset) / > sizeof(struct pda_rssi_cal_ext_entry); > > - if ((len - offset) % sizeof(struct pda_rssi_cal_ext_entry) || > - entries <= 0) { > + if (len < offset || > + (len - offset) % sizeof(struct pda_rssi_cal_ext_entry) || > + entries == 0) { > wiphy_err(dev->wiphy, "invalid rssi database.\n"); > goto err_data; > } >