[ILUG] /etc/fstab -what is /dev/pts ?

[Kenn Humborg]

> Could anyone tell me what the /dev/pts filesystem is in my 
> /etc/fstab file? Every time my system boots it complains 
> about /dev/pts not being supported by the kernel. Also what 
> is the /proc line in my /etc/fstab file for? If i remove it 
> and reboot it seems to prevent me from connecting to my ISP?

It's part of the pseudo terminal support.  Psuedo terminals
are used by remote login programs such as ssh and telnet,
by xterms and xterm-lookalikes.  Don't know why it would be
breaking your ISP connection.  Perhaps the ppp dialer uses
them.

To fix it, answer yes to CONFIG_DEVPTS_FS when doing a 
'make config' and re-compile your kernel.

> /etc/fstab:
> 
> /dev/hdc        /mnt/cdrom      iso9660
> user,exec,dev,suid,ro,noauto,gid=502,owner 0 0
> /dev/fd0        /mnt/floppy     ext2  
> user,exec,dev,suid,rw,noauto,gid=502,owner 0 0

Are you _really_ sure about these lines?  'user' means
that anybody can mount and unmount floppies and CDs.
'exec' means that you can run programs from floppies
and CDs.  That's all fine...

But 'dev' and 'suid'????   'dev' means that device
files on a floppy or CD will work.  'suid' means that
setuid bits on executables on a floppy or CD will 
be honoured.  Someone could do this on their own machine:

# mke2fs /dev/fd0
# mount -t ext2 /dev/fd0 /mnt/floppy
# mknod /mnt/hda b 3 0
# chmod 777 /mnt/floppy/hda
# cp /bin/bash /mnt/floppy
# chown root.root /mnt/floppy/bash
# chmod u+s /mnt/floppy/bash
# umount /mnt/floppy

Then they mount that disk on your machine and they 
can use /mnt/floppy/hda (instead of /dev/hda) and get
full access to your hard disk.  Or they could just run
/mnt/floppy/bash and have a root shell.

Later,
Kenn