Shared memory permissions question

[Joost Bekkers]

On Tue, Aug 16, 2005 at 04:51:15PM +0400, Dmitry Agaphonov wrote:
> Hello,
> 
> 
> I have user A from group G creating shared memory M with permissions
> 0060.  After this, A fails to attach M due to permission denied.
> However, another user B from the same group G successfully attaches M.
> User A manages to attach only if permissions 0600 added for M.
> 
> Why the system disregards group permissions for user A?  Is it correct
> behaviour?
> 
> This is happening on FreeBSD 4.11-STABLE.
> 

This is normal&correct behaviour.

Access if granted on a best match basis:

if user==owner then only user rights are applied
elseif user is member of group then only group rights are applied
else only 'other' rights are applied.

-- 
greetz Joost
joost at jodocus.org