From mboxrd@z Thu Jan 1 00:00:00 1970 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D47A1C433F5 for ; Fri, 4 Mar 2022 15:06:15 +0000 (UTC) Received: from localhost ([::1]:45534 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nQ9VW-0000EH-NO for qemu-devel@archiver.kernel.org; Fri, 04 Mar 2022 10:06:14 -0500 Received: from eggs.gnu.org ([209.51.188.92]:39330) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nQ8rE-0005FR-04 for qemu-devel@nongnu.org; Fri, 04 Mar 2022 09:24:37 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:46340) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nQ8rB-0002Kn-5W for qemu-devel@nongnu.org; Fri, 04 Mar 2022 09:24:35 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1646403871; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=OpKErTmmTGnHwRYPOgvS0SjzqB/msUj5VLfFK6l1uDg=; b=gHqhMEGCwIN3bfSBCs1u+8L/W0pYon8e3WST8H8WbMvAkvri/H22Cr8TFrodi59bK4wIHC l02heNvaTBmHQhszMJtFK974E7FKbzzg8cjlqrl/XofGFiUGxemU8sbMdRtYBIdt3N/+lg 77RDVm9jG7y7XtZHEGELvC1cgzRdkOI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-164-K5UzOdwTMwiUK7h2Pbhu3A-1; Fri, 04 Mar 2022 09:24:28 -0500 X-MC-Unique: K5UzOdwTMwiUK7h2Pbhu3A-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EC239801AFE; Fri, 4 Mar 2022 14:24:26 +0000 (UTC) Received: from sirius.home.kraxel.org (unknown [10.39.192.99]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7FE12866E9; Fri, 4 Mar 2022 14:24:26 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id 2F8A718009B8; Fri, 4 Mar 2022 15:21:25 +0100 (CET) From: Gerd Hoffmann To: qemu-devel@nongnu.org Subject: [PULL 25/35] hw/i386: Improve bounds checking in OVMF table parsing Date: Fri, 4 Mar 2022 15:21:13 +0100 Message-Id: <20220304142123.956171-26-kraxel@redhat.com> In-Reply-To: <20220304142123.956171-1-kraxel@redhat.com> References: <20220304142123.956171-1-kraxel@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kraxel@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=kraxel@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Eduardo Habkost , Peter Maydell , =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= , Akihiko Odaki , "Michael S. Tsirkin" , Thomas Huth , Richard Henderson , Christian Schoenebeck , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , "Dr . David Alan Gilbert" , Dov Murik , Gerd Hoffmann , Paolo Bonzini Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Dov Murik When pc_system_parse_ovmf_flash() parses the optional GUIDed table in the end of the OVMF flash memory area, the table length field is checked for sizes that are too small, but doesn't error on sizes that are too big (bigger than the flash content itself). Add a check for maximal size of the OVMF table, and add an error report in case the size is invalid. In such a case, an error like this will be displayed during launch: qemu-system-x86_64: OVMF table has invalid size 4047 and the table parsing is skipped. Signed-off-by: Dov Murik Reviewed-by: Dr. David Alan Gilbert Reviewed-by: Daniel P. Berrangé Message-Id: <20220222071906.2632426-2-dovmurik@linux.ibm.com> Signed-off-by: Gerd Hoffmann --- hw/i386/pc_sysfw_ovmf.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/hw/i386/pc_sysfw_ovmf.c b/hw/i386/pc_sysfw_ovmf.c index f4dd92c58825..df15c9737b93 100644 --- a/hw/i386/pc_sysfw_ovmf.c +++ b/hw/i386/pc_sysfw_ovmf.c @@ -24,6 +24,7 @@ */ #include "qemu/osdep.h" +#include "qemu/error-report.h" #include "hw/i386/pc.h" #include "cpu.h" @@ -66,7 +67,13 @@ void pc_system_parse_ovmf_flash(uint8_t *flash_ptr, size_t flash_size) ptr -= sizeof(uint16_t); tot_len = le16_to_cpu(*(uint16_t *)ptr) - sizeof(guid) - sizeof(uint16_t); - if (tot_len <= 0) { + if (tot_len < 0 || tot_len > (ptr - flash_ptr)) { + error_report("OVMF table has invalid size %d", tot_len); + return; + } + + if (tot_len == 0) { + /* no entries in the OVMF table */ return; } -- 2.35.1