From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx01-fr.bfs.de ([193.174.231.67]:18165 "EHLO mx01-fr.bfs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751106AbbKZMWD (ORCPT ); Thu, 26 Nov 2015 07:22:03 -0500 Message-ID: <5656F95C.60107@bfs.de> (sfid-20151126_132208_869280_152C1223) Date: Thu, 26 Nov 2015 13:21:48 +0100 From: walter harms Reply-To: wharms@bfs.de MIME-Version: 1.0 To: Dan Carpenter CC: Stanislaw Gruszka , Helmut Schaa , Kalle Valo , linux-wireless@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [patch] rt2x00: type bug in _rt2500usb_register_read() References: <20151126115523.GD10556@mwanda> In-Reply-To: <20151126115523.GD10556@mwanda> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: Am 26.11.2015 12:55, schrieb Dan Carpenter: > This code causes a static checker bug. > > drivers/net/wireless/ralink/rt2x00/rt2500usb.c:232 _rt2500usb_register_read() > warn: passing casted pointer 'value' to 'rt2500usb_register_read()' 32 vs 16. > > If the low 16 bits were initialized to zero then this code would only be > a problem on big endian systems. But in this case this is case the low > 16 bits are never initialized. This is called from a function which is > created using a macro: > > RT2X00DEBUGFS_OPS(csr, "0x%.8x\n", u32); > > We end up copying uninitialized data to the user which is bogus and an > information leak. > > Signed-off-by: Dan Carpenter > --- > Not tested. Perhaps we should just remove this code since it has never > worked. > > diff --git a/drivers/net/wireless/ralink/rt2x00/rt2500usb.c b/drivers/net/wireless/ralink/rt2x00/rt2500usb.c > index b50d873..d26018f 100644 > --- a/drivers/net/wireless/ralink/rt2x00/rt2500usb.c > +++ b/drivers/net/wireless/ralink/rt2x00/rt2500usb.c > @@ -229,7 +229,10 @@ static void _rt2500usb_register_read(struct rt2x00_dev *rt2x00dev, > const unsigned int offset, > u32 *value) > { > - rt2500usb_register_read(rt2x00dev, offset, (u16 *)value); > + u16 tmp; > + > + rt2500usb_register_read(rt2x00dev, offset, &tmp); > + *value = tmp; > } > perhaps, cleaning *value would be sufficient ? Avoiding the need for a tmp var. *value = 0 rt2500usb_register_read(rt2x00dev, offset, (u16 *)value); re, wh > static void _rt2500usb_register_write(struct rt2x00_dev *rt2x00dev, > -- > To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >