Subject: Re: [patch] eicon: make buffer larger

From: Dan Carpenter <[email-masked]>
Date: Wed, 6 Oct 2010 10:31:17 +0200

On Wed, Oct 06, 2010 at 10:21:02AM +0200, Armin Schindler wrote:
> On Wed, 6 Oct 2010, Dan Carpenter wrote:
>> On Wed, Oct 06, 2010 at 09:25:44AM +0200, Armin Schindler wrote:
>>> On Mon, 4 Oct 2010, Dan Carpenter wrote:
>>>> In diva_mnt_add_xdi_adapter() we do this:
>>>>  strcpy (clients[id].drvName,     tmp);
>>>>  strcpy (clients[id].Dbg.drvName, tmp);
>>>>
>>>> The "clients[id].drvName" is a 128 character buffer and
>>>> "clients[id].Dbg.drvName" was originally a 16 character buffer but I've
>>>> changed it to 128 as well.  We don't actually use 128 characters but we
>>>> do use more than 16.
>>>
>>> I don't see any reason for that change. The driver names here do not use
>>> more than 16 characters and when filled, the length is checked anyway.
>>> Please avoid changing the size of that structure.
>>>
>>
>> drivers/isdn/hardware/eicon/debug.c diva_mnt_add_xdi_adapter()
>>   874      sprintf (tmp, "ADAPTER:%d SN:%u-%d",
>>                           12345678 90123 45 67
>>
>> 	That's a minimum 17 characters.
>>
>>   875               (int)logical,
>>   876               serial & 0x00ffffff,
>>   877               (byte)(((serial & 0xff000000) >> 24) + 1));
>>   878    } else {
>>   879      sprintf (tmp, "ADAPTER:%d SN:%u", (int)logical, serial);
>>   880    }
>
> this is tmp with a bigger size. It seems you are mixing the sizes of  
> drvName and tmp.
>

What I mean is that later on we use strcpy() to copy "tmp" into
"clients[id].Dbg.drvName"

   927    strcpy (clients[id].drvName,     tmp);
   928    strcpy (clients[id].Dbg.drvName, tmp);
                               ^
                    this buffer is only 16 chars

regards,
dan carpenter

> Armin