From patchwork Fri Nov 5 09:55:04 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Suchanek X-Patchwork-Id: 12604423 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8E394C4167D for ; Fri, 5 Nov 2021 09:55:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 78F2F61252 for ; Fri, 5 Nov 2021 09:55:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232968AbhKEJ6A (ORCPT ); Fri, 5 Nov 2021 05:58:00 -0400 Received: from smtp-out1.suse.de ([195.135.220.28]:51872 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232951AbhKEJ5y (ORCPT ); Fri, 5 Nov 2021 05:57:54 -0400 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id E6596212BD; Fri, 5 Nov 2021 09:55:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1636106111; 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=N2IrrNGggoBJszqOFq3EqLZ/1vvIbTQ/MEl4PSiVjrk=; b=O5S1I1vN2m29YuV+QfXPUec/wJqGbomni09qZHmaaYkHY02ezB84cpfAuwoWOd6pHkcy5C PZtiD4IVM1vbRD2b31RkrQ7/C8Id9S9yVJdAjp6L6eQrTUpY0vEqUT0vtdWo52U7U0QfQs cKQ9YljFxtnH1SkwBeeQlOylD5/PQ2c= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1636106111; 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=N2IrrNGggoBJszqOFq3EqLZ/1vvIbTQ/MEl4PSiVjrk=; b=PVdlto+ESoz/1dIczDDDBZU8SXphcj7LOSqZucxrH/9eB171xbwhOC3Er3e3QQ7uikKEPd 401tswzyswImc2CA== Received: from kitsune.suse.cz (kitsune.suse.cz [10.100.12.127]) by relay2.suse.de (Postfix) with ESMTP id A60D72C157; Fri, 5 Nov 2021 09:55:11 +0000 (UTC) From: Michal Suchanek To: keyrings@vger.kernel.org Cc: Michal Suchanek , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Alexander Gordeev , David Howells , Herbert Xu , "David S. Miller" , Luis Chamberlain , Jessica Yu , Mimi Zohar , Dmitry Kasatkin , James Morris , "Serge E. Hallyn" , Rob Herring , Lakshmi Ramasubramanian , Hari Bathini , Thiago Jung Bauermann , Frank van der Linden , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, linux-crypto@vger.kernel.org, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH 1/2] module: Use key_being_used_for for log messages in verify_appended_signature Date: Fri, 5 Nov 2021 10:55:04 +0100 Message-Id: <3e5ad3138ea72468027768bbd69f04a1dae44af8.1636105912.git.msuchanek@suse.de> X-Mailer: git-send-email 2.31.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: Add value for kexec appended signature and pass in key_being_used_for enum rather than a string to verify_appended_signature to produce log messages about the signature. Signed-off-by: Michal Suchanek --- arch/powerpc/kexec/elf_64.c | 2 +- arch/s390/kernel/machine_kexec_file.c | 2 +- crypto/asymmetric_keys/asymmetric_type.c | 1 + include/linux/verification.h | 3 ++- kernel/module.c | 3 ++- kernel/module_signing.c | 11 ++++++----- 6 files changed, 13 insertions(+), 9 deletions(-) diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c index e8dff6b23ac5..3aa5269f6e0f 100644 --- a/arch/powerpc/kexec/elf_64.c +++ b/arch/powerpc/kexec/elf_64.c @@ -158,7 +158,7 @@ int elf64_verify_sig(const char *kernel, unsigned long length) size_t kernel_len = length; return verify_appended_signature(kernel, &kernel_len, VERIFY_USE_PLATFORM_KEYRING, - "kexec_file"); + VERIFYING_KEXEC_APPENDED_SIGNATURE); } #endif /* CONFIG_KEXEC_SIG */ diff --git a/arch/s390/kernel/machine_kexec_file.c b/arch/s390/kernel/machine_kexec_file.c index 82260bb61060..37fcbb149368 100644 --- a/arch/s390/kernel/machine_kexec_file.c +++ b/arch/s390/kernel/machine_kexec_file.c @@ -32,7 +32,7 @@ int s390_verify_sig(const char *kernel, unsigned long length) return 0; return verify_appended_signature(kernel, &kernel_len, VERIFY_USE_PLATFORM_KEYRING, - "kexec_file"); + VERIFYING_KEXEC_APPENDED_SIGNATURE); } #endif /* CONFIG_KEXEC_SIG */ diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c index ad8af3d70ac0..6fd20eec3882 100644 --- a/crypto/asymmetric_keys/asymmetric_type.c +++ b/crypto/asymmetric_keys/asymmetric_type.c @@ -25,6 +25,7 @@ const char *const key_being_used_for[NR__KEY_BEING_USED_FOR] = { [VERIFYING_KEXEC_PE_SIGNATURE] = "kexec PE sig", [VERIFYING_KEY_SIGNATURE] = "key sig", [VERIFYING_KEY_SELF_SIGNATURE] = "key self sig", + [VERIFYING_KEXEC_APPENDED_SIGNATURE] = "kexec appended sig", [VERIFYING_UNSPECIFIED_SIGNATURE] = "unspec sig", }; EXPORT_SYMBOL_GPL(key_being_used_for); diff --git a/include/linux/verification.h b/include/linux/verification.h index c1cf0582012a..23748feb9e03 100644 --- a/include/linux/verification.h +++ b/include/linux/verification.h @@ -26,6 +26,7 @@ enum key_being_used_for { VERIFYING_KEXEC_PE_SIGNATURE, VERIFYING_KEY_SIGNATURE, VERIFYING_KEY_SELF_SIGNATURE, + VERIFYING_KEXEC_APPENDED_SIGNATURE, VERIFYING_UNSPECIFIED_SIGNATURE, NR__KEY_BEING_USED_FOR }; @@ -61,7 +62,7 @@ extern int verify_pefile_signature(const void *pebuf, unsigned pelen, #endif int verify_appended_signature(const void *data, size_t *len, struct key *trusted_keys, - const char *what); + enum key_being_used_for purpose); #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ #endif /* _LINUX_VERIFY_PEFILE_H */ diff --git a/kernel/module.c b/kernel/module.c index 1c421b0442e3..5f1cf989e1cf 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2891,7 +2891,8 @@ static int module_sig_check(struct load_info *info, int flags) */ if (flags == 0) { err = verify_appended_signature(mod, &info->len, - VERIFY_USE_SECONDARY_KEYRING, "module"); + VERIFY_USE_SECONDARY_KEYRING, + VERIFYING_MODULE_SIGNATURE); if (!err) { info->sig_ok = true; return 0; diff --git a/kernel/module_signing.c b/kernel/module_signing.c index 4c28cb55275f..cef72a6f6b5d 100644 --- a/kernel/module_signing.c +++ b/kernel/module_signing.c @@ -19,17 +19,18 @@ * @data: The data to be verified * @len: Size of @data. * @trusted_keys: Keyring to use for verification - * @what: Informational string for log messages + * @purpose: The use to which the key is being put */ int verify_appended_signature(const void *data, size_t *len, - struct key *trusted_keys, const char *what) + struct key *trusted_keys, + enum key_being_used_for purpose) { const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1; struct module_signature ms; size_t sig_len, modlen = *len; int ret; - pr_devel("==>%s(,%zu)\n", __func__, modlen); + pr_devel("==>%s %s(,%zu)\n", __func__, key_being_used_for[purpose], modlen); if (markerlen > modlen) return -ENODATA; @@ -44,7 +45,7 @@ int verify_appended_signature(const void *data, size_t *len, memcpy(&ms, data + (modlen - sizeof(ms)), sizeof(ms)); - ret = mod_check_sig(&ms, modlen, what); + ret = mod_check_sig(&ms, modlen, key_being_used_for[purpose]); if (ret) return ret; @@ -54,6 +55,6 @@ int verify_appended_signature(const void *data, size_t *len, return verify_pkcs7_signature(data, modlen, data + modlen, sig_len, trusted_keys, - VERIFYING_MODULE_SIGNATURE, + purpose, NULL, NULL); } From patchwork Fri Nov 5 09:55:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Suchanek X-Patchwork-Id: 12604421 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B8612C4167B for ; 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b=oS8DuB9/NxKVi6XlZqCfhYKCNZaLzolpEE4OwG5RC0Q63k5Wz7KyyF9jlGynT+jd78U5qQ YSbeVyL+23CqU6C7DFujES4L0ZEiAerV6wgsUfD/jSeoJ6WUhPfZUOR1wHjzqohdVL1tJz X/vt4Ls+zbQ3gQAkYnbkAneBaY59oSs= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1636106112; 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=KFKgqjsVVpDaPTDousPDt96FJKqdCU2sOOhjtib7BWc=; b=0WY1ADo1PNbzXrvYjvDKIkvN1mkI1KwMFhZvwgAgug53k6aNj+PVzRtAdvrSgNFeDgwNVH +J4twYvwweXD+tDg== Received: from kitsune.suse.cz (kitsune.suse.cz [10.100.12.127]) by relay2.suse.de (Postfix) with ESMTP id 8555A2C160; Fri, 5 Nov 2021 09:55:12 +0000 (UTC) From: Michal Suchanek To: keyrings@vger.kernel.org Cc: Michal Suchanek , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Alexander Gordeev , David Howells , Herbert Xu , "David S. Miller" , Luis Chamberlain , Jessica Yu , Mimi Zohar , Dmitry Kasatkin , James Morris , "Serge E. Hallyn" , Rob Herring , Lakshmi Ramasubramanian , Hari Bathini , Thiago Jung Bauermann , Frank van der Linden , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, linux-crypto@vger.kernel.org, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH 2/2] module: Move duplicate mod_check_sig users code to mod_parse_sig Date: Fri, 5 Nov 2021 10:55:05 +0100 Message-Id: X-Mailer: git-send-email 2.31.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: Multiple users of mod_check_sig check for the marker, then call mod_check_sig, extract signature length, and remove the signature. Put this code in one place together with mod_check_sig. Signed-off-by: Michal Suchanek --- include/linux/module_signature.h | 1 + kernel/module_signature.c | 56 ++++++++++++++++++++++++++++- kernel/module_signing.c | 26 +++----------- security/integrity/ima/ima_modsig.c | 22 ++---------- 4 files changed, 63 insertions(+), 42 deletions(-) diff --git a/include/linux/module_signature.h b/include/linux/module_signature.h index 7eb4b00381ac..1343879b72b3 100644 --- a/include/linux/module_signature.h +++ b/include/linux/module_signature.h @@ -42,5 +42,6 @@ struct module_signature { int mod_check_sig(const struct module_signature *ms, size_t file_len, const char *name); +int mod_parse_sig(const void *data, size_t *len, size_t *sig_len, const char *name); #endif /* _LINUX_MODULE_SIGNATURE_H */ diff --git a/kernel/module_signature.c b/kernel/module_signature.c index 00132d12487c..784b40575ee4 100644 --- a/kernel/module_signature.c +++ b/kernel/module_signature.c @@ -8,14 +8,36 @@ #include #include +#include #include #include +/** + * mod_check_sig_marker - check that the given data has signature marker at the end + * + * @data: Data with appended signature + * @len: Length of data. Signature marker length is subtracted on success. + */ +static inline int mod_check_sig_marker(const void *data, size_t *len) +{ + const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1; + + if (markerlen > *len) + return -ENODATA; + + if (memcmp(data + *len - markerlen, MODULE_SIG_STRING, + markerlen)) + return -ENODATA; + + *len -= markerlen; + return 0; +} + /** * mod_check_sig - check that the given signature is sane * * @ms: Signature to check. - * @file_len: Size of the file to which @ms is appended. + * @file_len: Size of the file to which @ms is appended (without the marker). * @name: What is being checked. Used for error messages. */ int mod_check_sig(const struct module_signature *ms, size_t file_len, @@ -44,3 +66,35 @@ int mod_check_sig(const struct module_signature *ms, size_t file_len, return 0; } + +/** + * mod_parse_sig - check that the given signature is sane and determine signature length + * + * @data: Data with appended signature. + * @len: Length of data. Signature and marker length is subtracted on success. + * @sig_len: Length of signature. Filled on success. + * @name: What is being checked. Used for error messages. + */ +int mod_parse_sig(const void *data, size_t *len, size_t *sig_len, const char *name) +{ + const struct module_signature *sig; + int rc; + + rc = mod_check_sig_marker(data, len); + if (rc) + return rc; + + if (*len < sizeof(*sig)) + return -ENODATA; + + sig = (const struct module_signature *)(data + (*len - sizeof(*sig))); + + rc = mod_check_sig(sig, *len, name); + if (rc) + return rc; + + *sig_len = be32_to_cpu(sig->sig_len); + *len -= *sig_len + sizeof(*sig); + + return 0; +} diff --git a/kernel/module_signing.c b/kernel/module_signing.c index cef72a6f6b5d..02bbca90f467 100644 --- a/kernel/module_signing.c +++ b/kernel/module_signing.c @@ -25,35 +25,17 @@ int verify_appended_signature(const void *data, size_t *len, struct key *trusted_keys, enum key_being_used_for purpose) { - const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1; struct module_signature ms; - size_t sig_len, modlen = *len; + size_t sig_len; int ret; - pr_devel("==>%s %s(,%zu)\n", __func__, key_being_used_for[purpose], modlen); + pr_devel("==>%s %s(,%zu)\n", __func__, key_being_used_for[purpose], *len); - if (markerlen > modlen) - return -ENODATA; - - if (memcmp(data + modlen - markerlen, MODULE_SIG_STRING, - markerlen)) - return -ENODATA; - modlen -= markerlen; - - if (modlen <= sizeof(ms)) - return -EBADMSG; - - memcpy(&ms, data + (modlen - sizeof(ms)), sizeof(ms)); - - ret = mod_check_sig(&ms, modlen, key_being_used_for[purpose]); + ret = mod_parse_sig(data, len, &sig_len, key_being_used_for[purpose]); if (ret) return ret; - sig_len = be32_to_cpu(ms.sig_len); - modlen -= sig_len + sizeof(ms); - *len = modlen; - - return verify_pkcs7_signature(data, modlen, data + modlen, sig_len, + return verify_pkcs7_signature(data, *len, data + *len, sig_len, trusted_keys, purpose, NULL, NULL); diff --git a/security/integrity/ima/ima_modsig.c b/security/integrity/ima/ima_modsig.c index fb25723c65bc..46917eb37fd8 100644 --- a/security/integrity/ima/ima_modsig.c +++ b/security/integrity/ima/ima_modsig.c @@ -37,33 +37,17 @@ struct modsig { * * Return: 0 on success, error code otherwise. */ -int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len, +int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t len, struct modsig **modsig) { - const size_t marker_len = strlen(MODULE_SIG_STRING); - const struct module_signature *sig; struct modsig *hdr; - size_t sig_len; - const void *p; + size_t sig_len, buf_len = len; int rc; - if (buf_len <= marker_len + sizeof(*sig)) - return -ENOENT; - - p = buf + buf_len - marker_len; - if (memcmp(p, MODULE_SIG_STRING, marker_len)) - return -ENOENT; - - buf_len -= marker_len; - sig = (const struct module_signature *)(p - sizeof(*sig)); - - rc = mod_check_sig(sig, buf_len, func_tokens[func]); + rc = mod_parse_sig(buf, &buf_len, &sig_len, func_tokens[func]); if (rc) return rc; - sig_len = be32_to_cpu(sig->sig_len); - buf_len -= sig_len + sizeof(*sig); - /* Allocate sig_len additional bytes to hold the raw PKCS#7 data. */ hdr = kzalloc(sizeof(*hdr) + sig_len, GFP_KERNEL); if (!hdr)