From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [patch 2/8] allow unprivileged umount
Date: Sat, 21 Apr 2007 00:55:06 -0700
Message-ID: <20070421005506.6a315bec.akpm@linux-foundation.org>
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To: Miklos Szeredi <miklos@szeredi.hu>
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On Fri, 20 Apr 2007 12:25:34 +0200 Miklos Szeredi <miklos@szeredi.hu> wrote:

> +static bool permit_umount(struct vfsmount *mnt, int flags)
> +{
>
> ...
>
> +	return mnt->mnt_uid == current->uid;
> +}

Yes, this seems very wrong.  I'd have thought that comparing user_struct*'s
would get us a heck of a lot closer to being able to support aliasing of
UIDs between different namespaces.