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Date:   Fri, 22 Jan 2021 15:35:34 +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 23/40] exec: handle idmapped mounts
In-Reply-To: <20210121131959.646623-24-christian.brauner@ubuntu.com>
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References: <20210121131959.646623-1-christian.brauner@ubuntu.com> <20210121131959.646623-24-christian.brauner@ubuntu.com>
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On Thu, 21 Jan 2021, Christian Brauner wrote:

> When executing a setuid binary the kernel will verify in bprm_fill_uid()
> that the inode has a mapping in the caller's user namespace before
> setting the callers uid and gid. Let bprm_fill_uid() handle idmapped
> mounts. If the inode is accessed through an idmapped mount it is mapped
> according to the mount's user namespace. Afterwards the checks are
> identical to non-idmapped mounts. 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/20210112220124.837960-32-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>