Re: [PATCH 1/1] file capabilities: remove cap_task_kill()

["Luiz Fernando N. Capitulino" <lcapitulino@mandriva.com.br>]

Em Fri, 29 Feb 2008 15:26:34 -0600
serge@hallyn.com escreveu:

| Quoting Luiz Fernando N. Capitulino (lcapitulino@mandriva.com.br):
| > Em Thu, 28 Feb 2008 11:38:17 -0600
| > serge@hallyn.com escreveu:
| > 
| > | The original justification for cap_task_kill() was as follows:
| > | 
| > | 	check_kill_permission() does appropriate uid equivalence checks.
| > | 	However with file capabilities it becomes possible for an
| > | 	unprivileged user to execute a file with file capabilities
| > | 	resulting in a more privileged task with the same uid.
| > | 
| > | However now that cap_task_kill() always returns 0 (permission
| > | granted) when p->uid==current->uid, the whole hook is worthless,
| > | and only likely to create more subtle problems in the corner cases
| > | where it might still be called but return -EPERM.  Those cases
| > | are basically when uids are different but euid/suid is equivalent
| > | as per the check in check_kill_permission().
| > | 
| > | This patch removes cap_task_kill().
| > 
| >  2.6.24 seems to have the same bug, what about a rediff for it and
| > submit the patch to -stable team?
| 
| Luiz, could you confirm that the below works?

 Yes, it does.

 Thanks.

-- 
Luiz Fernando N. Capitulino