From patchwork Thu Nov 25 18:02:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Suchanek X-Patchwork-Id: 12639723 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D4E01C433FE for ; Thu, 25 Nov 2021 18:05:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351170AbhKYSIu (ORCPT ); Thu, 25 Nov 2021 13:08:50 -0500 Received: from smtp-out2.suse.de ([195.135.220.29]:57242 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233741AbhKYSGq (ORCPT ); Thu, 25 Nov 2021 13:06:46 -0500 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 42D491FD3C; Thu, 25 Nov 2021 18:03:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1637863413; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=l0S/rnnLVvNbU+CCOjj4LWqQa7IdIcdMPBDgplAns6U=; b=RKhgYgumwvJoAQSsGPnYDj+iUVI8D4UZ40tFmowliQAdb+89lTJC7fINQv+liE3oLpVdZq YWyf4GXI5PKsipvnNP50uqYRLdawaTMeuVaUdHSBeoIgikhELwOd+UyGUoyHE3JVXhoV4g Q6/6rzZKN12y3pGVkKq4HxT/rLs5MOM= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1637863413; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=l0S/rnnLVvNbU+CCOjj4LWqQa7IdIcdMPBDgplAns6U=; b=uHz1kBfG6gD9l+Me+xoTs0h/Oult6KQZ0g+sXgatAGa3xXpm5190+t5RLzh1Pqhu85Rr3n 6hfHDRALXl8O44BQ== Received: from kitsune.suse.cz (kitsune.suse.cz [10.100.12.127]) by relay2.suse.de (Postfix) with ESMTP id EC8B9A3B87; Thu, 25 Nov 2021 18:03:32 +0000 (UTC) From: Michal Suchanek To: keyrings@vger.kernel.org Cc: Michal Suchanek , kexec@lists.infradead.org, Philipp Rudo , Mimi Zohar , Nayna , Rob Herring , linux-s390@vger.kernel.org, Vasily Gorbik , Lakshmi Ramasubramanian , Heiko Carstens , Jessica Yu , linux-kernel@vger.kernel.org, David Howells , Christian Borntraeger , Luis Chamberlain , Paul Mackerras , Hari Bathini , Alexander Gordeev , linuxppc-dev@lists.ozlabs.org, Frank van der Linden , Thiago Jung Bauermann , Daniel Axtens , buendgen@de.ibm.com, Michael Ellerman , Benjamin Herrenschmidt , Christian Borntraeger , Herbert Xu , "David S. Miller" , Dmitry Kasatkin , James Morris , "Serge E. Hallyn" , Sven Schnelle , Baoquan He , linux-crypto@vger.kernel.org, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH v2 2/6] powerpc/kexec_file: Add KEXEC_SIG support. Date: Thu, 25 Nov 2021 19:02:40 +0100 Message-Id: <8b30a3c6a4e845eb77f276298424811897efdebf.1637862358.git.msuchanek@suse.de> X-Mailer: git-send-email 2.31.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org Copy the code from s390x Signed-off-by: Michal Suchanek --- arch/powerpc/Kconfig | 11 +++++++++++ arch/powerpc/kexec/elf_64.c | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 47 insertions(+) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index ac0c515552fd..ecc1227a77f1 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -561,6 +561,17 @@ config KEXEC_FILE config ARCH_HAS_KEXEC_PURGATORY def_bool KEXEC_FILE +config KEXEC_SIG + bool "Verify kernel signature during kexec_file_load() syscall" + depends on KEXEC_FILE && MODULE_SIG_FORMAT + help + This option makes kernel signature verification mandatory for + the kexec_file_load() syscall. + + 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 PPC64_BUILD_ELF_V2_ABI bool diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c index eeb258002d1e..25dc1071feec 100644 --- a/arch/powerpc/kexec/elf_64.c +++ b/arch/powerpc/kexec/elf_64.c @@ -23,6 +23,7 @@ #include #include #include +#include static void *elf64_load(struct kimage *image, char *kernel_buf, unsigned long kernel_len, char *initrd, @@ -151,7 +152,42 @@ static void *elf64_load(struct kimage *image, char *kernel_buf, return ret ? ERR_PTR(ret) : NULL; } +#ifdef CONFIG_KEXEC_SIG +int elf64_verify_sig(const char *kernel, unsigned long kernel_len) +{ + const unsigned long marker_len = sizeof(MODULE_SIG_STRING) - 1; + struct module_signature *ms; + unsigned long sig_len; + int ret; + + if (marker_len > kernel_len) + return -EKEYREJECTED; + + if (memcmp(kernel + kernel_len - marker_len, MODULE_SIG_STRING, + marker_len)) + return -EKEYREJECTED; + kernel_len -= marker_len; + + ms = (void *)kernel + kernel_len - sizeof(*ms); + ret = mod_check_sig(ms, kernel_len, "kexec"); + if (ret) + return ret; + + sig_len = be32_to_cpu(ms->sig_len); + kernel_len -= sizeof(*ms) + sig_len; + + return verify_pkcs7_signature(kernel, kernel_len, + kernel + kernel_len, sig_len, + VERIFY_USE_PLATFORM_KEYRING, + VERIFYING_MODULE_SIGNATURE, + NULL, NULL); +} +#endif /* CONFIG_KEXEC_SIG */ + const struct kexec_file_ops kexec_elf64_ops = { .probe = kexec_elf_probe, .load = elf64_load, +#ifdef CONFIG_KEXEC_SIG + .verify_sig = elf64_verify_sig, +#endif };