http://bugs.winehq.org/show_bug.cgi?id=3498
--- Comment #25 from Matt Keenan tank.en.mate+winehq@gmail.com 2008-11-01 19:51:26 --- man 2 chown seems to say;
Only a privileged process (Linux: one with the CAP_CHOWN capability) may change the owner of a file. The owner of a file may change the group of the file to any group of which that owner is a member. A privileged process (Linux: with CAP_CHOWN) may change the group arbitrarily.
And my tests confirm this...
Now from memory some POSIX systems allow ordinary users to chown, but I think they are BSD derivatives (it's been a while since I admin'ed any non SVR4 or Linux machines).