Re: [patch 0/8] unprivileged mount syscall

H. Peter Anvin
2007-04-07T00:22:49Z

Jan Engelhardt wrote:
> On Apr 6 2007 16:16, H. Peter Anvin wrote:
>>>> - users can use bind mounts without having to pre-configure them in
>>>> /etc/fstab
>>>>
>> This is by far the biggest concern I see. I think the security implication of
>> allowing anyone to do bind mounts are poorly understood.
>
> $ whoami
> miklos
> $ mount --bind / ~/down_under
>
> later that day:
> # userdel -r miklos
>
> So both the source (/) and target (~/down_under) directory must be owned
> by the user before --bind may succeed.
>
> There may be other implications hpa might want to fill us in.

Consider backups, for example.

-hpa