Messages in this thread | | | Date | Fri, 20 Apr 2007 07:42:49 -0500 | From | "Serge E. Hallyn" <> | Subject | Re: [patch 0/8] mount ownership and unprivileged mount syscall (v4) |
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Quoting Miklos Szeredi (miklos@szeredi.hu): > This patchset has now been bared to the "lowest common denominator" > that everybody can agree on. Or at least there weren't any objections > to this proposal. > > Andrew, please consider it for -mm. > > Thanks, > Miklos > ---- > > v3 -> v4: > > - simplify interface as much as possible, now only a single option > ("user=UID") is used to control everything > - no longer allow/deny mounting based on file/directory permissions, > that approach does not always make sense > > ---- > This patchset adds support for keeping mount ownership information in > the kernel, and allow unprivileged mount(2) and umount(2) in certain > cases. > > The mount owner has the following privileges: > > - unmount the owned mount > - create a submount under the owned mount > > The sysadmin can set the owner explicitly on mount and remount. When > an unprivileged user creates a mount, then the owner is automatically > set to the user. > > The following use cases are envisioned: > > 1) Private namespace, with selected mounts owned by user. > E.g. /home/$USER is a good candidate for allowing unpriv mounts and > unmounts within. > > 2) Private namespace, with all mounts owned by user and having the > "nosuid" flag. User can mount and umount anywhere within the > namespace, but suid programs will not work. > > 3) Global namespace, with a designated directory, which is a mount > owned by the user. E.g. /mnt/users/$USER is set up so that it is > bind mounted onto itself, and set to be owned by $USER. The user > can add/remove mounts only under this directory. > > The following extra security measures are taken for unprivileged > mounts: > > - usermounts are limited by a sysctl tunable > - force "nosuid,nodev" mount options on the created mount
Very nice. I like these semantics.
I'll try to rework my laptop in the next few days to use this patchset as a test.
thanks, -serge - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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