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Message-ID: <5d98172d77a8a0f1e3daab44ad51bf38978cc053.camel@linux.ibm.com>
Subject: Re: [PATCH] lockdown: kexec_file: prevent unsigned kernel image
 when KEXEC_SIG not enabled
From:   Mimi Zohar <zohar@linux.ibm.com>
To:     Coiby Xu <coxu@redhat.com>, kexec@lists.infradead.org
Cc:     Matthew Garrett <mjg59@srcf.ucam.org>, Jiri Bohac <jbohac@suse.cz>,
        David Howells <dhowells@redhat.com>,
        linux-integrity@vger.kernel.org,
        Eric Biederman <ebiederm@xmission.com>,
        James Morris <jmorris@namei.org>,
        Matthew Garrett <mjg59@google.com>,
        open list <linux-kernel@vger.kernel.org>
Date:   Mon, 21 Nov 2022 13:23:57 -0500
In-Reply-To: <20221121072947.836672-1-coxu@redhat.com>
References: <20221121072947.836672-1-coxu@redhat.com>
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Hi Coiby,

On Mon, 2022-11-21 at 15:29 +0800, Coiby Xu wrote:
> A kernel builder may not enable KEXEC_SIG and some architectures like
> ppc64 simply don't have KEXEC_SIG. In these cases, unless both
> IMA_ARCH_POLICY and secure boot also enabled, lockdown doesn't prevent
> unsigned kernel image from being kexec'ed via the kexec_file_load
> syscall whereas it could prevent one via the kexec_load syscall. Mandate
> signature verification for those cases.
> 
> Fixes: 155bdd30af17 ("kexec_file: Restrict at runtime if the kernel is locked down")
> Cc: Matthew Garrett <mjg59@srcf.ucam.org>
> Cc: Jiri Bohac <jbohac@suse.cz>
> Cc: David Howells <dhowells@redhat.com>
> Cc: kexec@lists.infradead.org
> Cc: linux-integrity@vger.kernel.org
> Signed-off-by: Coiby Xu <coxu@redhat.com>

Other than correcting the function name to mandate_signature_verificati
on(),

Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>