Subject: Re: [PATCH 1/3] xen: xenbus driver must not accept invalid
 transaction ids
To: Juergen Gross <jgross@suse.com>, linux-kernel@vger.kernel.org,
        xen-devel@lists.xenproject.org
References: <20161222071948.23862-1-jgross@suse.com>
 <20161222071948.23862-2-jgross@suse.com>
From: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Message-ID: <6ff2c379-4c23-3b9e-c877-9da74bf3879e@oracle.com>
Date: Thu, 22 Dec 2016 10:38:53 -0500
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On 12/22/2016 02:19 AM, Juergen Gross wrote:
> When accessing Xenstore in a transaction the user is specifying a
> transaction id which he normally obtained from Xenstore when starting
> the transaction. Xenstore is validating a transaction id against all
> known transaction ids of the connection the request came in. As all
> requests of a domain not being the one where Xenstore lives share
> one connection, validation of transaction ids of different users of
> Xenstore in that domain should be done by the kernel of that domain
> being the multiplexer between the Xenstore users in that domain and
> Xenstore.
>
> In order to prohibit one Xenstore user to be able to "hijack" a
> transaction from another user the xenbus driver has to verify a
> given transaction id against all known transaction ids of the user
> before forwarding it to Xenstore.
>
> Signed-off-by: Juergen Gross <jgross@suse.com>


Should this go to stable trees as well?


Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>