Re: uid of user who mounts

From: Steve French (smfrench_at_austin.rr.com)
Date: 07/31/04

  • Next message: Lee Revell: "Re: input system: EVIOCSABS(abs) ioctl disabled, why?" 
    To: "Randy.Dunlap" <rddunlap@osdl.org>
Date:	Fri, 30 Jul 2004 22:34:01 -0500

    Thanks - I had missed that - and it is a little cleaner to call it
    "user" than "mount_uid" in the line in /proc/mounts, and there are no
    existing parms returned that are similar (except "username" which should
    be easy enough to understand). Interestingly I did not see other
    filesystems returning that in /proc/mounts (I slightly prefer having it
    stored in the filesystems kernel code and returned in showopts not just
    put by userspace in the file mtab) - the only minor annoyance is that /
    etc/mtab returns the username (rather than the uid).

    On Fri, 2004-07-30 at 19:08 -0700, Randy.Dunlap wrote:
    > On Fri, 30 Jul 2004 21:05:09 -0500 Steve French wrote:
    >
    > | To allow user unmounts of cifs shares (much like the setuid smbumount
    > | utility allows for smbfs), it has been suggested that the cifs vfs could
    > | return the uid of the mounter in /proc/mounts This would avoid having
    > | to add an ioctl (as smbfs did) and seems as secure as the ioctl approach
    > | (to get the uid of the original mounter).
    > |
    > | If user mounts are allowed, is there any worse security exposure in
    > | letting the tool check the uid who mounted via /proc/mounts (to allow
    > | user unmount).
    > |
    > | Is there any precedent for the name for the name of such a parm? I was
    > | thinking of "mnt_uid" since simply using "uid=" would seem to overload
    > | the meaning of "uid", which is already used as a mount parm by various
    > | filesystems to signify the default uid for files ( ie in the cifs case
    > | when mounting to Windows - and Unix CIFS protocol extensions are not
    > | enabled) and it is not always the case that the default uid for files
    > | would be the same as the uid of the person who mounted.
    >
    > For the last question, looks like "user=" is already used for that.
    > See 'man mount':
    >
    > user Allow an ordinary user to mount the file system. The
    > name of the mounting user is written to mtab so that he
    > can unmount the file system again. This option implies
    > the options noexec, nosuid, and nodev (unless overridden
    > by subsequent options, as in the option line
    > user,exec,dev,suid).
    >
    >
    >
    > --
    > ~Randy

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  • Next message: Lee Revell: "Re: input system: EVIOCSABS(abs) ioctl disabled, why?"

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