[OpenIndiana-discuss] Solaris privileges and seteuid()

[Jim Klimov]

2012-08-21 2:18, Gordon Ross пишет:
> On Fri, Aug 17, 2012 at 5:44 AM, Frank Lahm <franklahm at gmail.com> wrote:
>> 2012/8/17 James Relph <james at themacplace.co.uk>:
> [...]
>>>
>>> Thanks very much for that confirmation, really doesn't seem obvious in a lot of the documentation!  I don't have a system handy to test today (will do over the weekend) but I'll try and get a better idea of how that works over the weekend (in particular after a reboot, what UID/GID will a file/folder show (ie. with ls) until the same user logs in again and the new ephemeral mapping is created?).
>>
>> ephemeral ids break setuid/seteuid because they are not static on a
>> _running_ system. They may change anytime. Thus any POSIX compliant
>> application relying on these functions for privileges can not use
>> them.
>
> Really?  Where is your evidence?  I don't think I've ever seen one
> change except after a reboot.


As a wild guess (no evidence and no code reading):
* Can this happen upon restart of idmap daemon (i.e. state stored
   only in RAM)?
* Upon an ungraceful crash (as in kill -9 due to memory leaks,
   which I saw piling up over 1-2 months, with the daemon consuming
   about 3Gb of memory and then a CPU core sometimes, on SXCE 117)?

 From what I've seen, it uses an embedded SQL database which may
store the mappings and survive even reboots, but I have no idea
how really sturdy and reliable that mechanism is, especially in
modern revisions.

//Jim