Re: [PATCH 0/7] Initial support for user namespace owned mounts

Colin Walters
2015-07-20T17:55:04Z

On Thu, Jul 16, 2015, at 12:47 AM, Eric W. Biederman wrote:

> With that said desktop environments have for a long time been
> automatically mounting whichever filesystem you place in your computer,
> so in practice what this is really about is trying to align the kernel
> with how people use filesystems.

There is a large attack surface difference between mounting a device
that someone physically plugged into the computer (and note typically
it's required that the active console be unlocked as well[1]) versus
allowing any "unprivileged" process at any time to do it.

Many server setups use "unprivileged" uids that otherwise wouldn't
be able to exploit bugs in filesystem code.

[1] https://bugzilla.gnome.org/show_bug.cgi?id=653520
"AutomountManager also keeps track of the current session availability
(using the ConsoleKit and gnome-screensaver DBus interfaces) and
inhibits mounting if the current session is locked, or another session
is in use instead."