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Date:   Fri, 22 Jan 2021 14:47:59 +1100 (AEDT)
From:   James Morris <jmorris@namei.org>
To:     Christian Brauner <christian.brauner@ubuntu.com>
cc:     Alexander Viro <viro@zeniv.linux.org.uk>,
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Subject: Re: [PATCH v6 12/40] namei: handle idmapped mounts in may_*()
 helpers
In-Reply-To: <20210121131959.646623-13-christian.brauner@ubuntu.com>
Message-ID: <2ec5e6b6-768c-dad-3365-53c129579eb@namei.org>
References: <20210121131959.646623-1-christian.brauner@ubuntu.com> <20210121131959.646623-13-christian.brauner@ubuntu.com>
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On Thu, 21 Jan 2021, Christian Brauner wrote:

> The may_follow_link(), may_linkat(), may_lookup(), may_open(),
> may_o_create(), may_create_in_sticky(), may_delete(), and may_create()
> helpers determine whether the caller is privileged enough to perform the
> associated operations. Let them handle idmapped mounts by mapping the
> inode or fsids according to the mount's user namespace. Afterwards the
> checks are identical to non-idmapped inodes. The patch takes care to
> retrieve the mount's user namespace right before performing permission
> checks and passing it down into the fileystem so the user namespace
> can't change in between by someone idmapping a mount that is currently
> not idmapped. If the initial user namespace is passed nothing changes so
> non-idmapped mounts will see identical behavior as before.
> 
> Link: https://lore.kernel.org/r/20210112220124.837960-20-christian.brauner@ubuntu.com
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: David Howells <dhowells@redhat.com>
> Cc: Al Viro <viro@zeniv.linux.org.uk>
> Cc: linux-fsdevel@vger.kernel.org
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>


Reviewed-by: James Morris <jamorris@linux.microsoft.com>


-- 
James Morris
<jmorris@namei.org>