From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EE185C6778F for ; Thu, 26 Jul 2018 13:39:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9BC4020685 for ; Thu, 26 Jul 2018 13:39:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9BC4020685 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730135AbeGZO4Z (ORCPT ); Thu, 26 Jul 2018 10:56:25 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:56122 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729410AbeGZO4Z (ORCPT ); Thu, 26 Jul 2018 10:56:25 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E3DFD15A2; Thu, 26 Jul 2018 06:39:29 -0700 (PDT) Received: from [10.4.12.81] (melchizedek.emea.arm.com [10.4.12.81]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3D3013F6A8; Thu, 26 Jul 2018 06:39:27 -0700 (PDT) Subject: Re: [PATCH v12 15/16] arm64: kexec_file: add kernel signature verification support To: AKASHI Takahiro Cc: catalin.marinas@arm.com, will.deacon@arm.com, dhowells@redhat.com, vgoyal@redhat.com, herbert@gondor.apana.org.au, davem@davemloft.net, dyoung@redhat.com, bhe@redhat.com, arnd@arndb.de, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, ard.biesheuvel@linaro.org, bhsharma@redhat.com, kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20180724065759.19186-1-takahiro.akashi@linaro.org> <20180724065759.19186-16-takahiro.akashi@linaro.org> From: James Morse Message-ID: Date: Thu, 26 Jul 2018 14:39:25 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20180724065759.19186-16-takahiro.akashi@linaro.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Akashi, On 24/07/18 07:57, AKASHI Takahiro wrote: > With this patch, kernel verification can be done without IMA security > subsystem enabled. Turn on CONFIG_KEXEC_VERIFY_SIG instead. > > On x86, a signature is embedded into a PE file (Microsoft's format) header > of binary. Since arm64's "Image" can also be seen as a PE file as far as > CONFIG_EFI is enabled, we adopt this format for kernel signing. > > You can create a signed kernel image with: > $ sbsign --key ${KEY} --cert ${CERT} Image Reviewed-by: James Morse > diff --git a/arch/arm64/kernel/kexec_image.c b/arch/arm64/kernel/kexec_image.c > index d64f5e9f9d22..578d358632d0 100644 > --- a/arch/arm64/kernel/kexec_image.c > +++ b/arch/arm64/kernel/kexec_image.c > @@ -102,7 +106,18 @@ static void *image_load(struct kimage *image, > return ERR_PTR(ret); > } > > +#ifdef CONFIG_KEXEC_IMAGE_VERIFY_SIG > +static int image_verify_sig(const char *kernel, unsigned long kernel_len) > +{ > + return verify_pefile_signature(kernel, kernel_len, NULL, > + VERIFYING_KEXEC_PE_SIGNATURE); > +} > +#endif This is identical to x86's PE image verification helper. We can clean this up later by providing some kexec_image_verify_pe() in the core kexec_file code. Its not worth doing now. > const struct kexec_file_ops kexec_image_ops = { > .probe = image_probe, > .load = image_load, > +#ifdef CONFIG_KEXEC_IMAGE_VERIFY_SIG > + .verify_sig = image_verify_sig, > +#endif > }; Thanks, James