On 04/30/2015 08:55 AM, Stephen Smalley wrote:
> On 04/30/2015 05:41 AM, Inamdar Sharif wrote:
>> Hi Guys,
>>
>> I just came across the change
>> https://android.googlesource.com/kernel/common/+/ba733f9857b966459316d0cd33b8da2e22f62d7d
>>
>>  
>>
>> These are some of the questions:
>>
>> 1)What level of security this can provide?? Can anyone explain me with
>> an example?
> 
> See http://marc.info/?l=selinux&m=142861645215267&w=2
> 
>> 2)Also do we have any policy changes which would be required??
> 
> In order to use this mechanism, you need to update the target policy
> version to 30 (either change the default POLICYVERS to 30 in
> external/sepolicy/Android.mk or override it on the make command-line or
> in your BoardConfig) and you need to write allow rules with ioctl
> command whitelists.  Otherwise, nothing changes by default.
> 
>> Currently we have “ioctl” as the generic permission , so this means that
>> with this we have to specify which ioctl which source can
>> access??(correct me if I am wrong)
> 
> The ioctl whitelists are only applied if specified in policy; if no
> whitelist is specified for a given (domain, type, class) triple, then it
> only checks the existing ioctl generic permission.  So you can apply the
> ioctl whitelisting selectively.
> 
>> Also doing this will not add to the policy ??
> 
> Not sure what you mean, but you have to add allow rules with ioctl
> whitelists if you want to control them at that granularity.  But you
> still must be allowed ioctl permission in the first place, or no access
> will be granted.  So this mechanism can only further restrict ioctl
> access to specific whitelists; it never allows something that would have
> been denied.

Also, note that there have been a couple of bug fixes to the original
kernel patch so you'll want to cherry-pick those as well if using this
mechanism.

And you will need a version of libsepol and checkpolicy that supports
policy version 30.  Those changes have been applied on AOSP master and
to the upstream selinux repository.



_______________________________________________
Seandroid-list mailing list
[email protected]
To unsubscribe, send email to [email protected].
To get help, send an email containing "help" to 
[email protected].

Reply via email to