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Subjectchvt issue
HI all
I was reading vt driver
and I saw
/*
* To have permissions to do most of the vt ioctls, we either have
* to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
*/
perm = 0;
if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
perm = 1;

(lines 382-388 - drivers/char/vt_ioctl.c)

After reading the comment I thinked I can change vt
from one of my own to another one of mine.

so I opened vc/2 and vc/3 and a pts/0
$ w
01:26:45 up 1:33, 5 users, load average: 0,84, 0,66, 0,97
USER TTY LOGIN@ IDLE JCPU PCPU WHAT
alx vc/2 01:07 18:51 0.00s 0.00s -bash
alx vc/3 01:25 48.00s 0.00s 0.00s -bash
alx :0 23:55 ?xdm? 4:21 0.84s gnome-session
alx pts/0 01:22 0.00s 0.08s 0.00s w

I went to vc/3 and I did
$ tty
/dev/vc/3
$ chvt 2
as i expected I changed my tty to 2
after that I tryied to do the same from pts/0
and

$ tty
/dev/pts/0
$ chvt 2
chvt: VT_ACTIVATE: Operation not permitted
$

After that I went in vc/2
and I did
$ chvt 12
after that i was watching at my syslog writing messages...
I tryed the same from pts/0
and
$ chvt 12
Couldnt get a file descriptor referring to the console

So, there are some things I couldn't get about virtual terminal ioctls
and fd...
please note that use chvt having CAP_SYS_TTY_CONFIG (root) works fine.

Is it possible to change terminal from an unprivileged user ?

THanks in advance
for the time you'll spend answering me.

Alessandro
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