From patchwork Wed Sep 16 15:15:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Laszlo Ersek X-Patchwork-Id: 273541 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2608CC43461 for ; Wed, 16 Sep 2020 15:16:58 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 6C5BE22250 for ; Wed, 16 Sep 2020 15:16:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="FzMzzpwI" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6C5BE22250 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:45514 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kIZB2-0000WB-I6 for qemu-devel@archiver.kernel.org; Wed, 16 Sep 2020 11:16:56 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:58538) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kIZ9c-00088K-Qd for qemu-devel@nongnu.org; Wed, 16 Sep 2020 11:15:28 -0400 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:49117 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kIZ9a-0004rJ-MZ for qemu-devel@nongnu.org; Wed, 16 Sep 2020 11:15:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1600269325; 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; bh=Glyy05U7HMwiadYOzDcXSCP5pNfTc7CsfYnVHPHEZVY=; b=FzMzzpwI0VIC0ZucGkq3szjFWKrJp6WrTHXloiO/zbaYiL7gjCNFqeBXVz05+rbqdv3gkY xSGQTtHktbMejQdpxW6tz9iGWqztWNHHkifM13vSEij51VEFsYSviu1VRPVFatH1pOsAxq dvIL+Vzfott/si/5QptyhVdE6mqxx+I= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-477-ndjcJvl0MoqL14JkcUsAWw-1; Wed, 16 Sep 2020 11:15:19 -0400 X-MC-Unique: ndjcJvl0MoqL14JkcUsAWw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B794880EF8A for ; Wed, 16 Sep 2020 15:15:18 +0000 (UTC) Received: from lacos-laptop-7.usersys.redhat.com (ovpn-113-131.ams2.redhat.com [10.36.113.131]) by smtp.corp.redhat.com (Postfix) with ESMTP id DC4255DEB5; Wed, 16 Sep 2020 15:15:11 +0000 (UTC) From: Laszlo Ersek To: qemu-devel@nongnu.org Subject: [PATCH] hw/nvram/fw_cfg: fix FWCfgDataGeneratorClass::get_data() consumption Date: Wed, 16 Sep 2020 17:15:10 +0200 Message-Id: <20200916151510.22767-1-lersek@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=lersek@redhat.com X-Mimecast-Spam-Score: 0.002 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=207.211.31.81; envelope-from=lersek@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/16 11:15:25 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -50 X-Spam_score: -5.1 X-Spam_bar: ----- X-Spam_report: (-5.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-2.999, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= , =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= , Gerd Hoffmann Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The documentation on g_byte_array_free() says: > Returns > > the element data if free_segment is FALSE, otherwise NULL. The element > data should be freed using g_free(). Because we currently call g_byte_array_free() with free_segment=TRUE, we end up passing data=NULL to fw_cfg_add_file(). On the plus side, fw_cfg_data_read() and fw_cfg_dma_transfer() both deal with NULL data gracefully: QEMU does not crash when the guest reads such an item, the guest just gets a properly sized, but zero-filled blob. However, the bug breaks UEFI HTTPS boot, as the IANA_TLS_CIPHER array, generated otherwise correctly by the "tls-cipher-suites" object, is in effect replaced with a zero blob. Fix the issue by passing free_segment=FALSE to g_byte_array_free(): - the caller (fw_cfg_add_from_generator()) temporarily assumes ownership of the generated byte array, - then ownership of the byte array is transfered to fw_cfg, as fw_cfg_add_file() links (not copies) "data" into fw_cfg. Cc: "Daniel P. Berrangé" Cc: "Philippe Mathieu-Daudé" Cc: Gerd Hoffmann Fixes: 3203148917d035b09f71986ac2eaa19a352d6d9d Signed-off-by: Laszlo Ersek Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Daniel P. Berrangé --- hw/nvram/fw_cfg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c index f3a4728288eb..0e95d057fd51 100644 --- a/hw/nvram/fw_cfg.c +++ b/hw/nvram/fw_cfg.c @@ -1056,7 +1056,7 @@ bool fw_cfg_add_from_generator(FWCfgState *s, const char *filename, return false; } size = array->len; - fw_cfg_add_file(s, filename, g_byte_array_free(array, TRUE), size); + fw_cfg_add_file(s, filename, g_byte_array_free(array, FALSE), size); return true; }