From patchwork Thu Aug 5 14:59:45 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dimitri John Ledkov X-Patchwork-Id: 1513954 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=canonical.com header.i=@canonical.com header.a=rsa-sha256 header.s=20210705 header.b=ToOuC3sL; dkim-atps=neutral Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4GgWxV0ZZPz9sW8; Fri, 6 Aug 2021 01:00:14 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1mBeqw-0004AE-NQ; Thu, 05 Aug 2021 15:00:10 +0000 Received: from smtp-relay-canonical-1.internal ([10.131.114.174] helo=smtp-relay-canonical-1.canonical.com) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1mBeqv-00049j-1j for kernel-team@lists.ubuntu.com; Thu, 05 Aug 2021 15:00:09 +0000 Received: from mail-pj1-f72.google.com (mail-pj1-f72.google.com [209.85.216.72]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-canonical-1.canonical.com (Postfix) with ESMTPS id D7F6240665 for ; Thu, 5 Aug 2021 15:00:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical.com; s=20210705; t=1628175608; bh=7FPT1HXmitg4vK4VbCqbGwhKTTZukGaORXIxEvULu5I=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ToOuC3sLyCFlnVAjpVDF5HIfwpOcn36EmHnbcFcfQTO64O+Xd0G0LWVrmhARe5GMl CHG/csQ+6fh0BQn3eYn1qtQ3+JUb8qgftM2xR4xXo3LX9TpyvdvpyVKC7QcKhIBqYr 2SY5yjxUCdphnrfOiUS19PoSQ6wxCHVrCzJJviqOU8krpsncou9ikItWhjkfnlQfqS H7HOUCCCZSqlM8BeqbIzQeVhGdW1VRewS0cz8TyQOFW+GQNHvHvG+uUb/rAaHXqo+x ovfTALCurqvYxnbeQ8sxBYSc9U/DV1R7PFVUn4TAr6tyRgz5pqGors8sj5C1WLqGiM 4kbFfPazUSY1Q== Received: by mail-pj1-f72.google.com with SMTP id gt7-20020a17090af2c7b02901773c999dcbso101902pjb.6 for ; Thu, 05 Aug 2021 08:00:08 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=7FPT1HXmitg4vK4VbCqbGwhKTTZukGaORXIxEvULu5I=; b=sYxfT7puuBaDlOYFVrLhXgdmnX9QrCEuSbGlxOnae8Gm0xq0K9+oIZMeEmA+hASr0i diGeIXxmH0Pr7Wly824uPGNtNka9LEOyBAXNRrqBlpEZMUpmXpTJ8paMnDAka2STyT9F 0JFERyNJH+DaiCy8bwfb6mng495n/GFdh4x8QboR+Nk5m7zng3Wab5PCZJW0h5bUxtq/ o6qG/qWKDbernvZH+ABqRiuxSgEXPbIbHLhbNzIcWPeV9tRKkkmZc3pqQ/FLpcwn7qmL 0/csR7bVSQivnEUF9SWFgg/xu+71KiwaPMViJEAxihN/UC9auCJszr1TjwasY3VDUrKf P11w== X-Gm-Message-State: AOAM532LuU24/KVMwM+HnfYPNmjQteH+y3dop46o+gzk938OhxWSsM3K qxJG830hyQHWPt0gAvKn2tC/KZYQYVlLl/8L6SkaEpqcZXZwNcylN5u5fU9IjFX716i3ocXDG6z 6oBkrr3ONM5xZvmgSIVdyMEJfuv+dUJcHUy/N/OxfHw== X-Received: by 2002:a63:1d47:: with SMTP id d7mr1267436pgm.44.1628175607167; Thu, 05 Aug 2021 08:00:07 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxveqVXpgfgkDxlT6oifvxsHqd1Eowj1Nwspad1AtZqHWWzLWxwihUVxz5DgaCGbTJgbbYMkQ== X-Received: by 2002:a63:1d47:: with SMTP id d7mr1267419pgm.44.1628175606917; Thu, 05 Aug 2021 08:00:06 -0700 (PDT) Received: from localhost ([2a01:4b00:85fd:d700:15f9:47c1:a63f:6be0]) by smtp.gmail.com with ESMTPSA id 20sm9042985pgg.36.2021.08.05.08.00.05 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 05 Aug 2021 08:00:06 -0700 (PDT) From: Dimitri John Ledkov To: kernel-team@lists.ubuntu.com Subject: [HIRSUTE][PATCH 1/5] UBUNTU: SAUCE: integrity: Load mokx certs from the EFI MOK config table Date: Thu, 5 Aug 2021 15:59:45 +0100 Message-Id: <20210805145949.133895-2-dimitri.ledkov@canonical.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210805145949.133895-1-dimitri.ledkov@canonical.com> References: <20210805145949.133895-1-dimitri.ledkov@canonical.com> MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" Refactor load_moklist_certs() to load either MokListRT into db, or MokListXRT into dbx. Call load_moklist_certs() twice - first to load mokx certs into dbx, then mok certs into db. This thus now attempts to load mokx certs via the EFI MOKvar config table first, and if that fails, via the EFI variable. Previously mokx certs were only loaded via the EFI variable. Which fails when MokListXRT is large. Instead of large MokListXRT variable, only MokListXRT{1,2,3} are available which are not loaded. This is the case with Ubuntu's 15.4 based shim. This patch is required to address CVE-2020-26541 when certificates are revoked via MokListXRT. Fixes: ebd9c2ae369a ("integrity: Load mokx variables into the blacklist keyring") BugLink: https://bugs.launchpad.net/bugs/1928679 Signed-off-by: Dimitri John Ledkov Acked-by: Krzysztof Kozlowski Signed-off-by: Seth Forshee (cherry picked from commit a9e3aae16235d6af12509a64f1337da4485ccbae) Signed-off-by: Dimitri John Ledkov --- security/integrity/platform_certs/load_uefi.c | 74 ++++++++++--------- 1 file changed, 40 insertions(+), 34 deletions(-) diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c index d3e7ae04f5..b010b4ab5d 100644 --- a/security/integrity/platform_certs/load_uefi.c +++ b/security/integrity/platform_certs/load_uefi.c @@ -68,17 +68,18 @@ static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid, } /* - * load_moklist_certs() - Load MokList certs + * load_moklist_certs() - Load Mok(X)List certs + * @load_db: Load MokListRT into db when true; MokListXRT into dbx when false * - * Load the certs contained in the UEFI MokListRT database into the - * platform trusted keyring. + * Load the certs contained in the UEFI MokList(X)RT database into the + * platform trusted/denied keyring. * * This routine checks the EFI MOK config table first. If and only if - * that fails, this routine uses the MokListRT ordinary UEFI variable. + * that fails, this routine uses the MokList(X)RT ordinary UEFI variable. * * Return: Status */ -static int __init load_moklist_certs(void) +static int __init load_moklist_certs(const bool load_db) { struct efi_mokvar_table_entry *mokvar_entry; efi_guid_t mok_var = EFI_SHIM_LOCK_GUID; @@ -86,41 +87,55 @@ static int __init load_moklist_certs(void) unsigned long moksize; efi_status_t status; int rc; + const char *mokvar_name = "MokListRT"; + /* Should be const, but get_cert_list() doesn't have it as const yet */ + efi_char16_t *efivar_name = L"MokListRT"; + const char *parse_mokvar_name = "UEFI:MokListRT (MOKvar table)"; + const char *parse_efivar_name = "UEFI:MokListRT"; + efi_element_handler_t (*get_handler_for_guid)(const efi_guid_t *) = get_handler_for_db; + + if (!load_db) { + mokvar_name = "MokListXRT"; + efivar_name = L"MokListXRT"; + parse_mokvar_name = "UEFI:MokListXRT (MOKvar table)"; + parse_efivar_name = "UEFI:MokListXRT"; + get_handler_for_guid = get_handler_for_dbx; + } /* First try to load certs from the EFI MOKvar config table. * It's not an error if the MOKvar config table doesn't exist * or the MokListRT entry is not found in it. */ - mokvar_entry = efi_mokvar_entry_find("MokListRT"); + mokvar_entry = efi_mokvar_entry_find(mokvar_name); if (mokvar_entry) { - rc = parse_efi_signature_list("UEFI:MokListRT (MOKvar table)", + rc = parse_efi_signature_list(parse_mokvar_name, mokvar_entry->data, mokvar_entry->data_size, - get_handler_for_db); + get_handler_for_guid); /* All done if that worked. */ if (!rc) return rc; - pr_err("Couldn't parse MokListRT signatures from EFI MOKvar config table: %d\n", - rc); + pr_err("Couldn't parse %s signatures from EFI MOKvar config table: %d\n", + mokvar_name, rc); } /* Get MokListRT. It might not exist, so it isn't an error * if we can't get it. */ - mok = get_cert_list(L"MokListRT", &mok_var, &moksize, &status); + mok = get_cert_list(efivar_name, &mok_var, &moksize, &status); if (mok) { - rc = parse_efi_signature_list("UEFI:MokListRT", - mok, moksize, get_handler_for_db); + rc = parse_efi_signature_list(parse_efivar_name, + mok, moksize, get_handler_for_guid); kfree(mok); if (rc) - pr_err("Couldn't parse MokListRT signatures: %d\n", rc); + pr_err("Couldn't parse %s signatures: %d\n", mokvar_name, rc); return rc; } if (status == EFI_NOT_FOUND) - pr_debug("MokListRT variable wasn't found\n"); + pr_debug("%s variable wasn't found\n", mokvar_name); else - pr_info("Couldn't get UEFI MokListRT\n"); + pr_info("Couldn't get UEFI %s\n", mokvar_name); return 0; } @@ -134,9 +149,8 @@ static int __init load_moklist_certs(void) static int __init load_uefi_certs(void) { efi_guid_t secure_var = EFI_IMAGE_SECURITY_DATABASE_GUID; - efi_guid_t mok_var = EFI_SHIM_LOCK_GUID; - void *db = NULL, *dbx = NULL, *mokx = NULL; - unsigned long dbsize = 0, dbxsize = 0, mokxsize = 0; + void *db = NULL, *dbx = NULL; + unsigned long dbsize = 0, dbxsize = 0; efi_status_t status; int rc = 0; @@ -178,23 +192,15 @@ static int __init load_uefi_certs(void) kfree(dbx); } - mokx = get_cert_list(L"MokListXRT", &mok_var, &mokxsize, &status); - if (!mokx) { - if (status == EFI_NOT_FOUND) - pr_debug("mokx variable wasn't found\n"); - else - pr_info("Couldn't get mokx list\n"); - } else { - rc = parse_efi_signature_list("UEFI:MokListXRT", - mokx, mokxsize, - get_handler_for_dbx); - if (rc) - pr_err("Couldn't parse mokx signatures %d\n", rc); - kfree(mokx); - } + /* Load the MokListXRT certs */ + rc = load_moklist_certs(false); + if (rc) + pr_err("Couldn't parse mokx signatures: %d\n", rc); /* Load the MokListRT certs */ - rc = load_moklist_certs(); + rc = load_moklist_certs(true); + if (rc) + pr_err("Couldn't parse mok signatures: %d\n", rc); return rc; }