From patchwork Mon Jan 10 13:49:56 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Suchanek X-Patchwork-Id: 12708833 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 289F3C433FE for ; Mon, 10 Jan 2022 13:50:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234725AbiAJNuZ (ORCPT ); Mon, 10 Jan 2022 08:50:25 -0500 Received: from smtp-out1.suse.de ([195.135.220.28]:36700 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233466AbiAJNuJ (ORCPT ); Mon, 10 Jan 2022 08:50:09 -0500 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 6CA33210F8; Mon, 10 Jan 2022 13:50:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1641822607; 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=9Sg8NmS9Cl8uGlravuAR0TWOLfnwUgnMmpUpTIKU9d8=; b=CTITD+ASPAe8vMUGqH1kuCV9b9rF10kpGg21BBa4hsgxOR3IJg4rU3J+a4FFBlKPjPmC+F XLUzgXSd5Vqy433TPBvUW/QBFfuqt3dQ97h4gIzMhkUdyy47+v9RCuR2sP2DaLUy2GBsT5 TBwGvm18mQfoe5KgwH730gJ1J+z2nMc= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1641822607; 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=9Sg8NmS9Cl8uGlravuAR0TWOLfnwUgnMmpUpTIKU9d8=; b=lrC7ADtMTbDQt8wQKX18n/99GXCakud6nVwAm5HwkIJY8FBXrzxu551+Z+RtzYsRzowx+2 vL/aV9XVemCKruAA== Received: from kitsune.suse.cz (kitsune.suse.cz [10.100.12.127]) by relay2.suse.de (Postfix) with ESMTP id 2619EA3B8B; Mon, 10 Jan 2022 13:50:07 +0000 (UTC) From: Michal Suchanek To: keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, linux-integrity@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-security-module@vger.kernel.org Subject: [PATCH v4 4/6] module: strip the signature marker in the verification function. Date: Mon, 10 Jan 2022 14:49:56 +0100 Message-Id: <96d29773b9ef418a71b1d8bbfd0a456a0f996ec6.1641822505.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 It is stripped by each caller separately. Note: this changes the error for kexec_file from EKEYREJECTED to ENODATA when the signature marker is missing. Signed-off-by: Michal Suchanek --- v3: - Philipp Rudo : Update the commit with note about change of raturn value - the module_signature.h is now no longer needed for kexec_file --- arch/powerpc/kexec/elf_64.c | 11 ----------- arch/s390/kernel/machine_kexec_file.c | 11 ----------- kernel/module.c | 7 +------ kernel/module_signing.c | 12 ++++++++++-- 4 files changed, 11 insertions(+), 30 deletions(-) diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c index 64cd314cce0d..6dec8151ef73 100644 --- a/arch/powerpc/kexec/elf_64.c +++ b/arch/powerpc/kexec/elf_64.c @@ -24,7 +24,6 @@ #include #include #include -#include static void *elf64_load(struct kimage *image, char *kernel_buf, unsigned long kernel_len, char *initrd, @@ -156,16 +155,6 @@ static void *elf64_load(struct kimage *image, char *kernel_buf, #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; - - 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; - return verify_appended_signature(kernel, &kernel_len, VERIFY_USE_PLATFORM_KEYRING, "kexec_file"); } diff --git a/arch/s390/kernel/machine_kexec_file.c b/arch/s390/kernel/machine_kexec_file.c index 345f2eab6e04..c3deccf1da83 100644 --- a/arch/s390/kernel/machine_kexec_file.c +++ b/arch/s390/kernel/machine_kexec_file.c @@ -12,7 +12,6 @@ #include #include #include -#include #include #include #include @@ -28,20 +27,10 @@ const struct kexec_file_ops * const kexec_file_loaders[] = { #ifdef CONFIG_KEXEC_SIG int s390_verify_sig(const char *kernel, unsigned long kernel_len) { - const unsigned long marker_len = sizeof(MODULE_SIG_STRING) - 1; - /* Skip signature verification when not secure IPLed. */ if (!ipl_secure_flag) return 0; - 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; - return verify_appended_signature(kernel, &kernel_len, VERIFY_USE_PLATFORM_KEYRING, "kexec_file"); } diff --git a/kernel/module.c b/kernel/module.c index 8481933dfa92..d91ca0f93a40 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2882,7 +2882,6 @@ static inline void kmemleak_load_module(const struct module *mod, static int module_sig_check(struct load_info *info, int flags) { int err = -ENODATA; - const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1; const char *reason; const void *mod = info->hdr; @@ -2890,11 +2889,7 @@ static int module_sig_check(struct load_info *info, int flags) * Require flags == 0, as a module with version information * removed is no longer the module that was signed */ - if (flags == 0 && - info->len > markerlen && - memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) { - /* We truncate the module to discard the signature */ - info->len -= markerlen; + if (flags == 0) { err = verify_appended_signature(mod, &info->len, VERIFY_USE_SECONDARY_KEYRING, "module"); if (!err) { diff --git a/kernel/module_signing.c b/kernel/module_signing.c index 30149969f21f..39a6dd7c6dd2 100644 --- a/kernel/module_signing.c +++ b/kernel/module_signing.c @@ -15,8 +15,7 @@ #include "module-internal.h" /** - * verify_appended_signature - Verify the signature on a module with the - * signature marker stripped. + * verify_appended_signature - Verify the signature on a module * @data: The data to be verified * @len: Size of @data. * @trusted_keys: Keyring to use for verification @@ -25,12 +24,21 @@ int verify_appended_signature(const void *data, unsigned long *len, struct key *trusted_keys, const char *what) { + const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1; struct module_signature *ms; unsigned long sig_len, modlen = *len; int ret; pr_devel("==>%s(,%lu)\n", __func__, modlen); + if (markerlen > modlen) + return -ENODATA; + + if (memcmp(data + modlen - markerlen, MODULE_SIG_STRING, + markerlen)) + return -ENODATA; + modlen -= markerlen; + if (modlen <= sizeof(*ms)) return -EBADMSG;