Very Computer

by **Mark T. Gra** » Fri, 27 Oct 1995 04:00:00

Quote:
>Can somebody please tell me how a user other than root can mount floppy
>disks? It kinda sucks having to switch to root everytime I want to mount
>anything. Also, more than one person uses my Linux machine and I don't
>want to have to give them the root password so they can use the floppy
>and CD-ROM drives.

>Thanks ...

>Arcadio

You need to configure your /etc/fstab file (see man fstab), here's a copy of
mine:
/dev/hdb2 swap swap defaults 1 1
/dev/hdb3 / ext2 defaults 1 1
/dev/hda1 /dosc msdos defaults 1 1
/dev/hdb1 /dosd msdos defaults 1 1
/dev/hdc /cdrom iso9660 defaults,user,ro,noauto 0 0
/dev/fd0 /dosa msdos user,noauto 0 0
/dev/fd0 /fd0 ext2 user,noauto 0 0
none /proc proc defaults 1 1
Using this a user can mount a cdrom by mount /cdrom a dos floppy by
mount /dosa and an ext2 floppy by mount /fd0 (no need for to specify
device or file type -- )

by **Lars Gullik Bj?nn** » Fri, 27 Oct 1995 04:00:00

> > Can somebody please tell me how a user other than root can mount floppy
> > disks? It kinda sucks having to switch to root everytime I want to mount
> > anything. Also, more than one person uses my Linux machine and I don't
> > want to have to give them the root password so they can use the floppy
> > and CD-ROM drives.

> > Thanks ...

> > Arcadio

> the command is su
> try to read the man page of su command
> --

No, this is the same solution he probaly is using.

The correct solution is to edit /etc/fstab
and add user? after the floppy (/dev/fd0) line.
(sorry do not trust my example read the man pages for fstab an mount)

------------------------------------------------------------------------------
Lars Gullik Bj?nnes |
Web: http://www.ifi.uio.no/~larsbj | Brainstorms feed on my mind!

------------------------------------------------------------------------------

by **~ZIO BUDD** » Fri, 27 Oct 1995 04:00:00

Quote:> Can somebody please tell me how a user other than root can mount floppy
> disks? It kinda sucks having to switch to root everytime I want to mount
> anything. Also, more than one person uses my Linux machine and I don't
> want to have to give them the root password so they can use the floppy
> and CD-ROM drives.
> Thanks ...
> Arcadio

the command is su
try to read the man page of su command
--

http://www.dsi.unimi.it/Users/Students/moreld/home.html
Student at the Computer Science Department of University of Milan...

Ask me for questions about LINUX and Games for PC, and see my home page
Tel. 02/2139959 ... Chiedere di Davide Michel

by **Casey C Zac** » Sat, 28 Oct 1995 04:00:00

Quote:> Use mtools.
> You need to
> chgrp floppy /usr/bin/mtools
> chmod g+s /usr/bin/mtools
> before it works for other users than root.

Yeah, but that's only for msdos floppies.
--
__
/ ` _.._ _ . ,__________________.

._| `~~~~~~~~~~~~~~~~~~'

by **Tahoma M. Toelk** » Sat, 28 Oct 1995 04:00:00

> > > Can somebody please tell me how a user other than root can mount floppy
> > > disks? It kinda sucks having to switch to root everytime I want to mount
> > > anything. Also, more than one person uses my Linux machine and I don't
> > > want to have to give them the root password so they can use the floppy
> > > and CD-ROM drives.

> > > Thanks ...

> > > Arcadio

> > the command is su
> > try to read the man page of su command
> > --

> No, this is the same solution he probaly is using.

> The correct solution is to edit /etc/fstab
> and add user? after the floppy (/dev/fd0) line.
> (sorry do not trust my example read the man pages for fstab an mount)

If there are multiple users, you should realize that this method
presents a large security risk. It would, however, require that the
would-be abuser be physically at the machine and understand Unix
filesystems.

--
---------------------------------------------------------------
| Tahoma M. Toelkes | 100% Micro$loth-free computing. |

---------------------------------------------------------------

by **Michal Spalins** » Sun, 29 Oct 1995 04:00:00

My /etc/group file contains the line

floppy::11:root,mspal,rjb,praczka,jasiak

As far as I can remember adding this line was all I had to do to
make the floppy drives accessible to the non-root users.

Good Luck!
Michal Spalinski.

by **Arcadio Alivio Since** » Sun, 29 Oct 1995 04:00:00

: If there are multiple users, you should realize that this method
: presents a large security risk. It would, however, require that the
: would-be abuser be physically at the machine and understand Unix
: filesystems.

This one guy said that he created a "floppy" group. People who
belong to this group can mount/umount. Then he gave people he trusted
membership to the "floppy" group. That sounds like a good solution to
the security problem.

Arcadio

by **Jim Elg** » Sun, 29 Oct 1995 04:00:00

>My /etc/group file contains the line
>floppy::11:root,mspal,rjb,praczka,jasiak
>As far as I can remember adding this line was all I had to do to
>make the floppy drives accessible to the non-root users.
>Good Luck!
>Michal Spalinski.

A neat way to let "normal" users mount floppies is by
including the "user" option in /etc/fstab. My floppy entry
looks like:

/dev/fd0 /mnt msdos noauto,user 1 1

Typing "man 8 mount" gives a complete list of available
options.

by **Lars Gullik Bj?nn** » Sun, 29 Oct 1995 04:00:00

> > No, this is the same solution he probaly is using.

> > The correct solution is to edit /etc/fstab
> > and add user? after the floppy (/dev/fd0) line.
> > (sorry do not trust my example read the man pages for fstab an mount)

> If there are multiple users, you should realize that this method
> presents a large security risk. It would, however, require that the
> would-be abuser be physically at the machine and understand Unix
> filesystems.

I do not see the security risk, have a look at my fstab:

/dev/fd0H1440 /mnt msdos rw,noauto,user,async
/dev/fd0 /mnt ext2 rw,noauto,user,async

I allow user to mount, but not to run programs from the floppies.
There could of course be somthing that I don't understand, or don't
regard as a security risk. Please tell me explicit what the security risk is.

------------------------------------------------------------------------------
Lars Gullik Bj?nnes |
Web: http://www.ifi.uio.no/~larsbj | Brainstorms feed on my mind!

------------------------------------------------------------------------------

by **Robert Nicho** » Sun, 29 Oct 1995 04:00:00

:> The correct solution is to edit /etc/fstab
:> and add user? after the floppy (/dev/fd0) line.
:> (sorry do not trust my example read the man pages for fstab an mount)
:
:If there are multiple users, you should realize that this method
:presents a large security risk. It would, however, require that the
:would-be abuser be physically at the machine and understand Unix
:filesystems.

No, there's no risk. The "user" option implies "noexec", "nosuid" and
"nodev". (Perhaps you were unaware of those options.) Aside from a
possible "ro" option, the non-root user isn't allowed to supply any
extra arguments to the 'mount' command.

The "noexec" option isn't needed for security. It just protects the
user from trying to run potentially incompatible foreign executables,
and can be easily circumvented by copying the file.

--

by **taavo** » Tue, 31 Oct 1995 04:00:00

>> > No, this is the same solution he probaly is using.

>> > The correct solution is to edit /etc/fstab
>> > and add user? after the floppy (/dev/fd0) line.
>> > (sorry do not trust my example read the man pages for fstab an mount)

>> If there are multiple users, you should realize that this method
>> presents a large security risk. It would, however, require that the
>> would-be abuser be physically at the machine and understand Unix
>> filesystems.

>I do not see the security risk, have a look at my fstab:

>/dev/fd0H1440 /mnt msdos rw,noauto,user,async
>/dev/fd0 /mnt ext2 rw,noauto,user,async

>I allow user to mount, but not to run programs from the floppies.
>There could of course be somthing that I don't understand, or don't
>regard as a security risk. Please tell me explicit what the security risk is.

How do you prevent people from running programs on a floppy-mounted directory?
If they are able to do this it is a pretty wide security hole, isn't it?
For example, one could copy a shell to floppy, change owner to root and
setuid,
(perhaps on anoter system), and run this, gaining access to the root shell,
(I think).

by **Robert Nicho** » Wed, 01 Nov 1995 04:00:00

:How do you prevent people from running programs on a floppy-mounted directory?
:If they are able to do this it is a pretty wide security hole, isn't it?
:For example, one could copy a shell to floppy, change owner to root and
:setuid,
:(perhaps on anoter system), and run this, gaining access to the root shell,
:(I think).

The "user" option implies:

nosuid -- Any attempt (except by root) to execute a file with the
SUID or SGID bits set will fail with EPERM.

nodev -- Any attempt to open a special device file wil fail with
EACCESS.

noexec -- Execute permission will not be recognized except for
directory files.

(The "noexec" option is just a convenience to block accidental attempts
to execute foreign binaries and can safely be overridden in /etc/fstab.)

--

by **Steve Worml** » Wed, 01 Nov 1995 04:00:00

: How do you prevent people from running programs on a floppy-mounted directory?
: If they are able to do this it is a pretty wide security hole, isn't it?
: For example, one could copy a shell to floppy, change owner to root and
: setuid,
: (perhaps on anoter system), and run this, gaining access to the root shell,
: (I think).

The user flag implies nodev nosuid and noexec
which makes it fairly safe

--
Steve Wormley
Systems Administrator of Mother.COM

Pager:800-765-8420

Very Computer

How to mount floppies other than as root?

How to mount floppies other than as root?

How to mount floppies other than as root?

How to mount floppies other than as root?

How to mount floppies other than as root?

How to mount floppies other than as root?

How to mount floppies other than as root?

How to mount floppies other than as root?

How to mount floppies other than as root?

How to mount floppies other than as root?

How to mount floppies other than as root?

How to mount floppies other than as root?

How to mount floppies other than as root?

How to mount floppies other than as root?