Re: No subshell ifnot root, delayed start with no internet connection

[/dev/rob0 <rob0 gmx co uk>]

On Tue, Dec 20, 2016 at 01:13:58PM +0100, Joerg Thuemmler wrote:
> chown("/dev/pts/1", 26, 5)              = -1 EPERM (Operation not permitted)

26 is a strange UID to use.  Most Linux distros allocating new user 
UIDs start at 500 or 1000.  Is the result different when using an 
account created by useradd/adduser [whichever is appropriate for your 
distro]?  Is Apparmor or SELinux in use?

> close(4)                                = 0
> write(2, "Cannot open master side of pty: "..., 69) = 69
> write(1, "\33[?1001s\33[?1002h\33[?1006h", 24) = 24
> write(1, "\33[?2004h", 8)               = 8
>
> the last lines on root's side
> =============================
snip
> chown("/dev/pts/1", 0, 5)               = 0
> chmod("/dev/pts/1", 0620)               = 0
> ioctl(4, TIOCSPTLCK, [0])               = 0
> ioctl(4, SNDCTL_TMR_TIMEBASE or SNDRV_TIMER_IOCTL_NEXT_DEVICE or TCGETS,
> {B38400 opost isig icanon echo ...}) = 0
> ioctl(4, TIOCGPTN, [1])                 = 0
> stat("/dev/pts/1", {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 1), ...}) = 0
> open("/dev/pts/1", O_RDWR)              = 5
>
> seems to me that's normal a user usually should not be allowed to 
> chown or chmod a /dev/pts/... but I don't have a clue, why that's 
> working on other people's machines.

I can't explain the magic of the Linux /dev/pts system, but yours is 
broken, so indeed this is probably better handled in a SuSE forum.

Looking in my own /dev/pts on my laptop, I own all the ptys.  On the 
multiuser system from which I send this mail, I see ptys owned by 
various active users.

The chown should have succeeded, because you would have already owned 
the pty.  The pty should have been created for you.  Which brings to 
mind another possibility of YDIW; are you trying to reallocate a pty 
which was already created by/for the root user?

Another thing to try, a long shot perhaps: leave root's mc running 
and using that /dev/pts/1, try the user's mc in a different terminal.
You should get something X > 1 for the /dev/pts/$X pty.
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