assigned_user_credentials = pr_stapdev

assigned_user_credentials = pr_stapdev

[Henrik /KaarPoSoft]

Dear all,

Systemtap version 2.1.

I have created a small systemtap script and compiled with "stap 
--privilege=stapsys".
As root, I can "staprun" the script just fine.

As root I have installed the script in "/lib/modules/`uname -r`/systemtap".

If I try "staprun" as a user in groups staprun and stapsys (but NOT 
stapdev), I get this error message:
ERROR: Your privilege credentials (stapdev) are insufficient to run this 
module (stapsys required).

I find this a bit strange, as the user is NOT a member of stapdev as 
claimed, but the user IS a member of stapsys as required.

The above scenario was working way back with systemtap version 1.8, but 
is now failing with 2.1.

I looked at commit 429a4963, which introduced this around line 756 in 
staprun/staprun_funcs.c:
   if (assigned_user_credentials)
     assigned_user_credentials = pr_stapdev;

If I change this to
     assigned_user_credentials |= pr_stapdev;
the above scenario works like a charm.

As I have very limited knowledge of systemtap, I would appreciate your 
comments on this workaround.

Am I doing something wrong, and should use a different combination of 
privileges and groups?
Or is there really a problem with systemtap?
And if there IS a problem, is the above workaround the correct solution?

Any help on this would be most appreciated...

/Henrik

Re: assigned_user_credentials = pr_stapdev

[Dave Brolley]

Hi Henrik,

This certainly appears to be a bug of some kind. I will investigate but, 
in the mean time, please take the time to create an official bug report. 
See http://sourceware.org/systemtap/wiki/HowToReportBugs for assistance.

Thanks for reporting this,
Dave

On 02/24/2013 11:52 AM, Henrik /KaarPoSoft wrote:
> Dear all,
>
> Systemtap version 2.1.
>
> I have created a small systemtap script and compiled with "stap 
> --privilege=stapsys".
> As root, I can "staprun" the script just fine.
>
> As root I have installed the script in "/lib/modules/`uname 
> -r`/systemtap".
>
> If I try "staprun" as a user in groups staprun and stapsys (but NOT 
> stapdev), I get this error message:
> ERROR: Your privilege credentials (stapdev) are insufficient to run 
> this module (stapsys required).
>
> I find this a bit strange, as the user is NOT a member of stapdev as 
> claimed, but the user IS a member of stapsys as required.
>
> The above scenario was working way back with systemtap version 1.8, 
> but is now failing with 2.1.
>
> I looked at commit 429a4963, which introduced this around line 756 in 
> staprun/staprun_funcs.c:
>   if (assigned_user_credentials)
>     assigned_user_credentials = pr_stapdev;
>
> If I change this to
>     assigned_user_credentials |= pr_stapdev;
> the above scenario works like a charm.
>
> As I have very limited knowledge of systemtap, I would appreciate your 
> comments on this workaround.
>
> Am I doing something wrong, and should use a different combination of 
> privileges and groups?
> Or is there really a problem with systemtap?
> And if there IS a problem, is the above workaround the correct solution?
>
> Any help on this would be most appreciated...
>
> /Henrik
>
>
>

Re: assigned_user_credentials = pr_stapdev

[Henrik /KaarPoSoft]

http://sourceware.org/bugzilla/show_bug.cgi?id=15193

On 02/25/2013 04:57 PM, Dave Brolley wrote:
> Hi Henrik,
>
> This certainly appears to be a bug of some kind. I will investigate but,
> in the mean time, please take the time to create an official bug report.
> See http://sourceware.org/systemtap/wiki/HowToReportBugs for assistance.
>
> Thanks for reporting this,
> Dave
>
> On 02/24/2013 11:52 AM, Henrik /KaarPoSoft wrote:
>> [...]
>> If I try "staprun" as a user in groups staprun and stapsys (but NOT
>> stapdev), I get this error message:
>> ERROR: Your privilege credentials (stapdev) are insufficient to run
>> this module (stapsys required).
>>
>> I find this a bit strange, as the user is NOT a member of stapdev as
>> claimed, but the user IS a member of stapsys as required.
>> [...]