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From: Christian Brauner <brauner@kernel.org>
To: Richard Weinberger <richard@nod.at>
Cc: alx@kernel.org, serge@hallyn.com, christian@brauner.io,
	ipedrosa@redhat.com, gscrivan@redhat.com,
	andreas.gruenbacher@gmail.com, acl-devel@nongnu.org,
	linux-man@vger.kernel.org, linux-api@vger.kernel.org,
	linux-fsdevel@vger.kernel.org, ebiederm@xmission.com
Subject: Re: [PATCH 3/3] man: Document pitfall with negative permissions and user namespaces
Date: Wed, 30 Aug 2023 10:19:35 +0200	[thread overview]
Message-ID: <20230830-bachbett-papier-0cc012ebc5ca@brauner> (raw)
In-Reply-To: <20230829205833.14873-4-richard@nod.at>

On Tue, Aug 29, 2023 at 10:58:33PM +0200, Richard Weinberger wrote:
> It is little known that user namespaces and some helpers
> can be used to bypass negative permissions.
> 
> Signed-off-by: Richard Weinberger <richard@nod.at>
> ---
> This patch applies to the shadow project.
> ---
>  man/subgid.5.xml | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/man/subgid.5.xml b/man/subgid.5.xml
> index e473768d..8ed281e5 100644
> --- a/man/subgid.5.xml
> +++ b/man/subgid.5.xml
> @@ -55,6 +55,15 @@
>        <filename>/etc/subgid</filename> if subid delegation is managed via subid
>        files.
>      </para>
> +    <para>
> +      Additionally, it's worth noting that the utilization of subordinate group
> +      IDs can affect the enforcement of negative permissions. User can drop their
> +      supplementary groups and bypass certain negative permissions.
> +      For more details see
> +      <citerefentry>
> +	<refentrytitle>user_namespaces</refentrytitle><manvolnum>7</manvolnum>
> +      </citerefentry>.
> +    </para>
>    </refsect1>

Looks good to me (content),
Acked-by: Christian Brauner <brauner@kernel.org>

  reply	other threads:[~2023-08-30 18:38 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-29 20:58 [PATCH 0/3] Document impact of user namespaces and negative permissions Richard Weinberger
2023-08-29 20:58 ` [PATCH 1/3] man: Document pitfall with negative permissions and user namespaces Richard Weinberger
2023-08-30  8:19   ` Christian Brauner
2023-08-29 20:58 ` [PATCH 2/3] user_namespaces.7: " Richard Weinberger
2023-08-29 21:32   ` Alejandro Colomar
2023-08-29 21:38     ` Alejandro Colomar
2023-08-29 21:40       ` Richard Weinberger
2023-08-29 21:39     ` Richard Weinberger
2023-08-29 21:40       ` Alejandro Colomar
2023-08-30  9:26     ` Alejandro Colomar
2023-08-30  8:18   ` Christian Brauner
2023-08-29 20:58 ` [PATCH 3/3] man: " Richard Weinberger
2023-08-30  8:19   ` Christian Brauner [this message]
2023-08-29 21:26 ` [PATCH 0/3] Document impact of user namespaces and negative permissions Alejandro Colomar
2023-08-29 21:32   ` Richard Weinberger
2023-09-13 14:35     ` Alejandro Colomar

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