From mboxrd@z Thu Jan  1 00:00:00 1970
From: srinivas.kandagatla@linaro.org (Srinivas Kandagatla)
Date: Wed, 07 Oct 2015 14:18:47 +0100
Subject: [PATCH v2 1/3] nvmem: core: make default user binary file
 root-access only
In-Reply-To: <20151007125531.GA7962@kroah.com>
References: <1444215536-10783-1-git-send-email-srinivas.kandagatla@linaro.org>
 <1444215647-10836-1-git-send-email-srinivas.kandagatla@linaro.org>
 <20151007125531.GA7962@kroah.com>
Message-ID: <56151BB7.5090407@linaro.org>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org



On 07/10/15 13:55, Greg KH wrote:
> On Wed, Oct 07, 2015 at 12:00:47PM +0100, Srinivas Kandagatla wrote:
>> As required by many providers like at24/at25/mxs-ocotp/qfprom and may be
>> other providers would want to allow root-only to read the nvmem content.
>> So making the defaults to be root-only access would address the request
>> and also provide flexibility to providers to specify there own permissions
>> on top of the root-only using the perm flag in nvmem_config.
>
> Eeek, no, don't mess with different permissions, that's not ok, be
> consistent and only allow root write access, that's why we have static
> build-time checks to ensure you get this correct and do not accidentally
> let a "normal" user access to things they shouldn't have access to.
Thanks for your inputs,

Code as it is in mainline would provide a write permission to root-only 
and read to all the group.

Fixing/removing the group read permissions should stop normal user 
accessing the binary file.


--srini
>
>> Making this dynamic did cut down lot of static binary attributes in the
>> code.
>
> Nothing wrong with static binary attributes, please use them instead.
>
> thanks,
>
> greg k-h
>