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[209.132.180.67]) by mx.google.com with ESMTP id p123-v6si9676944pfg.281.2018.07.23.23.59.15; Mon, 23 Jul 2018 23:59:15 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=YqMA37RP; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388585AbeGXIEL (ORCPT + 31 others); Tue, 24 Jul 2018 04:04:11 -0400 Received: from mail-pl0-f67.google.com ([209.85.160.67]:40373 "EHLO mail-pl0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388264AbeGXIEK (ORCPT ); Tue, 24 Jul 2018 04:04:10 -0400 Received: by mail-pl0-f67.google.com with SMTP id s17-v6so1328531plp.7 for ; Mon, 23 Jul 2018 23:59:12 -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=pwXt6vap8yHX0ws+sEoumnHhs6bkGBBWSifGoV32A7Y=; b=YqMA37RPrwDG7QMbekhUUHSkhSv6lFzDpMZn38BDZBonF4qxQNMpXVgwHX0+Qg4Oaf /3V2lz1+76QcGqE/OOehIRcxSCjbF29D+xDyrTkr7sDoabpzDYPx0ChmHhvLY1fX1Ugx nZr0y9zbP9jAzyB+admjVWsewji7m/SKzXCro= 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=pwXt6vap8yHX0ws+sEoumnHhs6bkGBBWSifGoV32A7Y=; b=GdCZRROwano2Wq3HRr5FL/1OFAK4LvATN6YaaI0l10PbOLo1SKXl59fRoZRcmXYojk KkKaX4p7ZFXWFbTtio5qF3xKiM/L6OosDqUzd5un+pbXw+HTBH3twOy4pUxvqZdE8Tsm fbTh7fCUC8NLIjlkPNzoZ6d5WDBN+/J/0UJ3ObItLPrjA+aOogtPk9/4FxLw2OtBMtZd IYJuRVZnuPZAFrh9v3EDwtWNPmkesPepmTRGgmgwWmEjMTbqJKbiA7WmUVDz+2xPAY71 bsRFMpiFj9nK2ROB6dV4vWNGKBPqFREiPY1HlpT7RrplkR/xz0yg855UxKxr+g6s1weS xSnw== X-Gm-Message-State: AOUpUlHqb0SSHUpwPqaiNQxXpboBvp6rUOCFQdcxbnw4aWNVHuvh9XPZ IqEDsc9p2J2V9BtJUp0bbv8k8g== X-Received: by 2002:a17:902:8486:: with SMTP id c6-v6mr15657253plo.283.1532415552316; Mon, 23 Jul 2018 23:59:12 -0700 (PDT) Received: from linaro.org ([121.95.100.191]) by smtp.googlemail.com with ESMTPSA id 21-v6sm21506976pgx.20.2018.07.23.23.59.11 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 23 Jul 2018 23:59:11 -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, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com Cc: ard.biesheuvel@linaro.org, james.morse@arm.com, bhsharma@redhat.com, kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, AKASHI Takahiro Subject: [PATCH v12 15/16] arm64: kexec_file: add kernel signature verification support Date: Tue, 24 Jul 2018 15:57:58 +0900 Message-Id: <20180724065759.19186-16-takahiro.akashi@linaro.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180724065759.19186-1-takahiro.akashi@linaro.org> References: <20180724065759.19186-1-takahiro.akashi@linaro.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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(+) -- 2.18.0 Reviewed-by: James Morse 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 d64f5e9f9d22..578d358632d0 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(h->magic))) return -EINVAL; + pr_debug("PE format: %s\n", + memcmp(&h->mz_magic, "MZ", 2) ? "no" : "yes"); + return 0; } @@ -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 + 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 };