Re: Network hang after c3f1010b30f7fc611139cfb702a8685741aa6827 with CIPSO & Smack

[Casey Schaufler <casey@schaufler-ca.com>]

On 7/6/2016 9:28 AM, David Ahern wrote:
> On 7/5/16 6:31 PM, Casey Schaufler wrote:
>> On 7/5/2016 5:49 PM, David Ahern wrote:
>>> On 7/5/16 5:38 PM, Casey Schaufler wrote:
>>>> I have encountered a system hang with my Smack
>>>> networking tests that bisects to the change below.
>>>> I can't say that I have any idea why the change
>>>> would impact the Smack processing, but there appears
>>>> to be some serious packet processing going on. The
>>>> Smack code is using CIPSO on the loopback interface.
>>>> The test is supposed to verify that labels can be
>>>> set on the packets using CIPSO. Unlabeled packets
>>>> do not appear to be impacted. I do not know if SELinux
>>>> is affected, and if not, why not. Smack and SELinux
>>>> use CIPSO differently.
>>>
>>> What are the commands to repeat the test?
>>>
>> There is a tar file attached with the tests.
>> Put the etc/smack/user file into /etc/smack/user.
>> In the tools-2012 directory run make to build
>> the tools. The test in question is called
>> testnetworking.sh and needs to be run as root.
>> You will need to configure Smack in the kernel,
>> of course.
>>
>
> I understand Paul's point and glad to see the changes are not causing issues with his SELinux testing.
>
> I have tried to reproduce the lockup you are seeing but not successful. I am using a jessie based VM with latest net-next kernel.
>
> root@kenny-jessie3:~/smack/tools-2012# zcat /proc/config.gz | grep SMACK
> CONFIG_SECURITY_SMACK=y
> CONFIG_SECURITY_SMACK_BRINGUP=y
> CONFIG_SECURITY_SMACK_NETFILTER=y
> # CONFIG_DEFAULT_SECURITY_SMACK is not set

CONFIG_DEFAULT_SECURITY_SMACK needs to be set.

>
> root@kenny-jessie3:~/smack/tools-2012# bash -x ./testnetworking.sh
> <no lockup>
>
> Send me your kernel config. Perhaps I do not have some config enabled.
>