romfs and su
 

hi all,

i am working actually on a custom ColdFire MCF5307 board,
uClinux version 2.6.36.2 (angelo@angel7) (gcc version 4.2.4) #45 PREEMPT Mon Feb 14 09:50:19 CET 2011


I have 2 users, root and test, and 2 groups, also root and test. Login works properly for both.
I tried tinylogin "su" and busybox "su", but there is no way to "su root" from "test".

i get "initgroups: Operation not permitted"

I also tried busybox.conf and [SUID] section, enabling SUID/SGID handling in the config,

[SUID]
su = ssx root.root


but trying to "su root" i have now a different permission error, this time by "setresgid", and still cannot su root.

Seems that "su" application must have "setuid" bit set (+s), but romfs don't allow this.
So i suspect using "su root" with romfs is not possible.

Every help is appreciated.

regards,
angelo