Re: [patch] [SCSI] bnx2i: use strlcpy() instead of memcpy() for strings

From: Dan Carpenter <dan.carpenter@oracle.com>
To: David Laight <David.Laight@ACULAB.COM>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>,
	Barak Witkowski <barak@broadcom.com>,
	Eddie Wai <eddie.wai@broadcom.com>,
	Michael Chan <mchan@broadcom.com>,
	linux-scsi@vger.kernel.org, netdev@vger.kernel.org,
	"David S. Miller" <davem@davemloft.net>
Subject: Re: [patch] [SCSI] bnx2i: use strlcpy() instead of memcpy() for strings
Date: Mon, 2 Jul 2012 13:48:43 +0300	[thread overview]
Message-ID: <20120702104843.GB4519@mwanda> (raw)
In-Reply-To: <AE90C24D6B3A694183C094C60CF0A2F6026B6F6F@saturn3.aculab.com>

On Mon, Jul 02, 2012 at 11:09:19AM +0100, David Laight wrote:
> > Subject: [patch] [SCSI] bnx2i: use strlcpy() instead of memcpy() for
> strings
> > 
> > DRV_MODULE_VERSION here is "2.7.2.2" which is only 8 chars but we copy
> > 12 bytes from the stack so it's a small information leak.
> > 
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > ---
> > This was just added to linux-next yesterday, but I'm not sure 
> > which tree it came from.
> > 
> > diff --git a/drivers/scsi/bnx2i/bnx2i_init.c 
> > b/drivers/scsi/bnx2i/bnx2i_init.c
> > index 7729a52..b17637a 100644
> > --- a/drivers/scsi/bnx2i/bnx2i_init.c
> > +++ b/drivers/scsi/bnx2i/bnx2i_init.c
> > @@ -400,7 +400,7 @@ int bnx2i_get_stats(void *handle)
> >  	if (!stats)
> >  		return -ENOMEM;
> >  
> > -	memcpy(stats->version, DRV_MODULE_VERSION,
> sizeof(stats->version));
> > +	strlcpy(stats->version, DRV_MODULE_VERSION,
> sizeof(stats->version));
> >  	memcpy(stats->mac_add1 + 2, hba->cnic->mac_addr, ETH_ALEN);
> 
> Doesn't that leak the original contents of the last bytes of
> stats->version instead?

I'm pretty sure we set those to zero in bnx2x_handle_drv_info_req().

regards,
dan carpenter