Re: [PATCH] private mounts

[Eric Van Hensbergen <ericvh@gmail.com>]

On 5/1/05, Miklos Szeredi <miklos@szeredi.hu> wrote:
> 
> As someone pointed out, CAP_SYS_ADMIN processes can already escape the
> chroot jail with CLONE_NEWNS.  (fd=open("."); clone(CLONE_NEWNS);
> [child:] fchdir(fd); chdir(".."))
> 

This really does seem like a bug.  Is there are a reason behind this
"feature", or should one of us be looking into a patch to correct
this?

Miklos you earlier suggested:
>>>How about fixing fchdir, so it checks whether you gone outside the
>>>tree under current->fs->rootmnt?  Should be fairly easy to do.

         -eric