Subject: Re: Accessing user-land memory without safe functions
To: Jonathan Corbet <corbet@lwn.net>
References: <5660AC06.8080300@eng.utah.edu> <20151203171237.73877893@lwn.net>
Cc: linux-kernel@vger.kernel.org
From: Scotty Bauer <sbauer@eng.utah.edu>
Message-ID: <5660DF1B.6070307@eng.utah.edu>
Date: Thu, 3 Dec 2015 17:32:27 -0700
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101
 Thunderbird/38.3.0
MIME-Version: 1.0
In-Reply-To: <20151203171237.73877893@lwn.net>
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1534
Lines: 44

Hi Jon,

Thanks for the response.

Here is one such example, although benign due to the
function being called with CAP_SYS_ADMIN. I'll work on patches for some of the
other issues and send those soon as well.

https://lkml.org/lkml/2015/12/1/566


On 12/03/2015 05:12 PM, Jonathan Corbet wrote:
> On Thu, 3 Dec 2015 13:54:30 -0700
> Scotty Bauer <sbauer@eng.utah.edu> wrote:
> 
>> Since I've seen this a couple times now I'm wondering if my
>> understanding of touching user-land memory is flawed.
>>
>> For the above example Ioctl, the proper way to get access to those fields
>> through the safe copy_from_user or get_user() functions, correct?
>>
>> I'm wondering if I should submit patches to fix the issues I've found,
>> but now I'm doubting whether they're really issues at all.
> 
> They sound like bugs to me, though it would be easier to say for sure with
> a pointer to a specific function in the kernel source.  Please point
> something out, or, perhaps better, send a patch fixing one of them.
> 
> Thanks,
> 
> jon
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
> 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/