From patchwork Wed Jul 11 07:42:02 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: AKASHI Takahiro X-Patchwork-Id: 10519047 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 8EA756032C for ; Wed, 11 Jul 2018 07:43:57 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7EFC628756 for ; Wed, 11 Jul 2018 07:43:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 70C6D28E7C; Wed, 11 Jul 2018 07:43:57 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 19C8028756 for ; Wed, 11 Jul 2018 07:43:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=O3Lq1SLJuPFti0y10wxZNilAuutnFwzkd5CA/XgO+T8=; b=ojBmzMByB0gNwN1rQj7gjgyy5g 9npF3x+XW3ohA6P2KXO1FniN2w6tuUWgUGdu87QmQGNBIcfreQpndUbJVQQE2ppMh14XMd5rHtAZX R5AukyATgqNyWMm1gbf6YQXUoN59RsMXTcid87yKyFt34S7IOmFuvIjfZpElRgXqlH6uQaZa+WAa9 6jLzlxFCW45+8wtDTaJhCrHhA4I17hdJRz+q357Tt6iwxF65AW7jr+zaJfEUNkQhb4iW7JwveXPgr QBYPar9CjcFrAdOqIi/T9CSHqJnBVeqUUtGxCBi2+cg7emVBTx8G7VPhw8vNx3SrW3K/C976/TLDp hefL5H6g==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1fd9mx-0006h9-Ta; Wed, 11 Jul 2018 07:43:51 +0000 Received: from mail-pf0-x243.google.com ([2607:f8b0:400e:c00::243]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1fd9md-00060s-8V for linux-arm-kernel@lists.infradead.org; Wed, 11 Jul 2018 07:43:49 +0000 Received: by mail-pf0-x243.google.com with SMTP id e10-v6so17876193pfn.1 for ; Wed, 11 Jul 2018 00:43:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=IhXU1taVFqTvONKqzouhydG5S7Jk/KaBxJ/e0+WeXgw=; b=eekxUjV21HslWOHRESAr06L0Kztm+FKq2OFDkoPcAr+yWsaGuXIQFf2ChsDETAo8V1 kdb+Qd7+i9Kq0EobklijY/i+iCpJ3ba5J8KWnrVcEA2ey8ZR6QZFOpqTtcjrq96yRDja 8sGI6sSDNFbVpnDPOYLscJ+dPMmD/gsZr2RUU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=IhXU1taVFqTvONKqzouhydG5S7Jk/KaBxJ/e0+WeXgw=; b=A3KEp3SyQlJDZvdn0t3ylEA71EvGTbGD7VVc/V+WlD6CBgdqcwJJA4PmsJE4zYFxIf 2nVBUxcQ9S6LB324fjfAB3sgjfgASo9XtRCezOQ9AAAkV68cteI7QLxLeLFTDFQnnRBj SHt7t8HV9Umv4cDnEagUMkIJC1uVP6XPkFBc4ICZbjkrN9F4OQa/1Uj4ZphaUMzn2L8+ rvFrb8Cz0p1H6O+uO8y4FDVjoQFhbxeBgui+vPtFSCipeZLHY2ZXjK0dOoYTRp0VQztv IxaQb0KeqgefS1g4ygmmqlzeKM9B5f34KymAf01yV+3SVtHfs98s1yhD2imgMG1EwtQZ CpAQ== X-Gm-Message-State: APt69E0LJMedwk863w0h0hNsKDuo+nip8ZnhQ6lGeeTazXf0VD+yZqw2 qBOaSNt7YF2VJ2aPbZR7Ek5D3A== X-Google-Smtp-Source: AAOMgpe7KUObUERCYs4GhLO3asB1/y7ZLD/sUIH9aL2QZ6bVBGpZUeCl2EL12PGWZQWYqEKb3QnHrA== X-Received: by 2002:a62:ec41:: with SMTP id k62-v6mr28760983pfh.206.1531295000777; Wed, 11 Jul 2018 00:43:20 -0700 (PDT) Received: from linaro.org ([121.95.100.191]) by smtp.googlemail.com with ESMTPSA id w123-v6sm33118200pfb.38.2018.07.11.00.43.20 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 11 Jul 2018 00:43:20 -0700 (PDT) From: AKASHI Takahiro To: 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 Subject: [PATCH v11 14/15] arm64: kexec_file: add kernel signature verification support Date: Wed, 11 Jul 2018 16:42:02 +0900 Message-Id: <20180711074203.3019-15-takahiro.akashi@linaro.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180711074203.3019-1-takahiro.akashi@linaro.org> References: <20180711074203.3019-1-takahiro.akashi@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20180711_004331_416736_BABB3AA0 X-CRM114-Status: GOOD ( 15.94 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: ard.biesheuvel@linaro.org, bhsharma@redhat.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, AKASHI Takahiro , james.morse@arm.com, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP 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 Signed-off-by: AKASHI Takahiro Cc: Catalin Marinas Cc: Will Deacon --- arch/arm64/Kconfig | 24 ++++++++++++++++++++++++ arch/arm64/kernel/kexec_image.c | 15 +++++++++++++++ 2 files changed, 39 insertions(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index a9a3a5583c8b..1445eb2fc833 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -844,6 +844,30 @@ config KEXEC_FILE for kernel and initramfs as opposed to list of segments as accepted by previous system call. +config KEXEC_VERIFY_SIG + bool "Verify kernel signature during kexec_file_load() syscall" + depends on KEXEC_FILE + help + Select this option to verify a signature with loaded kernel + image. If configured, any attempt of loading a image without + valid signature will fail. + + In addition to that option, you need to enable signature + verification for the corresponding kernel image type being + loaded in order for this to work. + +config KEXEC_IMAGE_VERIFY_SIG + bool "Enable Image signature verification support" + default y + depends on KEXEC_VERIFY_SIG + depends on EFI && SIGNED_PE_FILE_VERIFICATION + help + Enable Image signature verification support. + +comment "Support for PE file signature verification disabled" + depends on KEXEC_VERIFY_SIG + depends on !EFI || !SIGNED_PE_FILE_VERIFICATION + config CRASH_DUMP bool "Build kdump crash kernel" help diff --git a/arch/arm64/kernel/kexec_image.c b/arch/arm64/kernel/kexec_image.c index df1e341d3a28..bb0a95add197 100644 --- a/arch/arm64/kernel/kexec_image.c +++ b/arch/arm64/kernel/kexec_image.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -28,6 +29,9 @@ static int image_probe(const char *kernel_buf, unsigned long kernel_len) !memcmp(&h->magic, ARM64_MAGIC, sizeof(ARM64_MAGIC))) return -EINVAL; + pr_debug("PE format: %s\n", + memcmp(&h->mz_magic, "MZ", 2) ? "no" : "yes"); + return 0; } @@ -107,7 +111,18 @@ 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 + 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 };