From patchwork Mon Feb 20 17:12:53 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robbie Harwood X-Patchwork-Id: 13146767 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 433B6C636CC for ; Mon, 20 Feb 2023 17:13:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231534AbjBTRNz (ORCPT ); Mon, 20 Feb 2023 12:13:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51610 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232116AbjBTRNy (ORCPT ); Mon, 20 Feb 2023 12:13:54 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E1FAADBFF for ; Mon, 20 Feb 2023 09:13:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1676913185; h=from:from:reply-to:subject:subject: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=0XAQlgOMPIfazufHJ1cw7n8xZDJ+yyG6hELMNmQg+HQ=; b=d7UbaOA6tfCqOoVYDobPvyyRoRaNJ8u38ft4nzUYvGxBqKdGe3LhTt3ENApje9SsMyK5/E SjobHDrLniEw38lkMFfzl9r5K3sJidlL0OdTscOavu60LMApY9x2Pre04qomVtR5QdSjq9 AASNgKBKuQ0lKWNFGY3gY9AoC3ReU2I= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-387-Ou9OnCZ2MQKmAIsUkBGQCg-1; Mon, 20 Feb 2023 12:13:04 -0500 X-MC-Unique: Ou9OnCZ2MQKmAIsUkBGQCg-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 0AAD81C06EC6 for ; Mon, 20 Feb 2023 17:13:04 +0000 (UTC) Received: from eesha.redhat.com (unknown [10.22.9.38]) by smtp.corp.redhat.com (Postfix) with ESMTP id DA69414171B8; Mon, 20 Feb 2023 17:13:03 +0000 (UTC) From: Robbie Harwood To: keyrings@vger.kernel.org, David Howells Cc: Robbie Harwood Subject: [PATCH v2 1/2] verify_pefile: relax wrapper length check Date: Mon, 20 Feb 2023 12:12:53 -0500 Message-Id: <20230220171254.592347-2-rharwood@redhat.com> In-Reply-To: <20230220171254.592347-1-rharwood@redhat.com> References: <20230220171254.592347-1-rharwood@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.7 Precedence: bulk List-ID: X-Mailing-List: keyrings@vger.kernel.org The PE Format Specification (section "The Attribute Certificate Table (Image Only)") states that `dwLength` is to be rounded up to 8-byte alignment when used for traversal. Therefore, the field is not required to be an 8-byte multiple in the first place. Accordingly, pesign has not performed this alignment since version 0.110. This causes kexec failure on pesign'd binaries with "PEFILE: Signature wrapper len wrong". Update the comment and relax the check. Link: https://learn.microsoft.com/en-us/windows/win32/debug/pe-format#the-attribute-certificate-table-image-only Link: https://github.com/rhboot/pesign Signed-off-by: Robbie Harwood --- crypto/asymmetric_keys/verify_pefile.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/crypto/asymmetric_keys/verify_pefile.c b/crypto/asymmetric_keys/verify_pefile.c index 7553ab18db89..fe1bb374239d 100644 --- a/crypto/asymmetric_keys/verify_pefile.c +++ b/crypto/asymmetric_keys/verify_pefile.c @@ -135,11 +135,15 @@ static int pefile_strip_sig_wrapper(const void *pebuf, pr_debug("sig wrapper = { %x, %x, %x }\n", wrapper.length, wrapper.revision, wrapper.cert_type); - /* Both pesign and sbsign round up the length of certificate table - * (in optional header data directories) to 8 byte alignment. + /* sbsign rounds up the length of certificate table (in optional + * header data directories) to 8 byte alignment. However, the PE + * specification states that while entries are 8-byte aligned, this is + * not included in their length, and as a result, pesign has not + * rounded up since 0.110. */ - if (round_up(wrapper.length, 8) != ctx->sig_len) { - pr_debug("Signature wrapper len wrong\n"); + if (wrapper.length > ctx->sig_len) { + pr_debug("Signature wrapper bigger than sig len (%x > %x)\n", + ctx->sig_len, wrapper.length); return -ELIBBAD; } if (wrapper.revision != WIN_CERT_REVISION_2_0) {