From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4AFE8606A330 for ; Mon, 9 Nov 2026 16:48:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=SETrX5Cg Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1xQSWo-0002uV-DY; Mon, 09 Nov 2026 11:47:35 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1xQSVK-0002Au-2v for qemu-devel@nongnu.org; Mon, 09 Nov 2026 11:46:09 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1xQSVF-0000yF-IP for qemu-devel@nongnu.org; Mon, 09 Nov 2026 11:45:56 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1794242749; 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=QbGEdXAUtqumOcFjpDX55Qd+K7L869gfapjJ/VMHGFc=; b=SETrX5Cgkvy0G4pkQLqDAFEaVexZV3/evtod2RxctKEOdBa14L4NQOK8BAIApC6Q+yIuVs 8l+sOqVqHWu0GCpswFeoHw2ISBH/AH12KYCqAjzX3El8a+T1K5ePGNNhG45ghmCSqkEKnz fzuNU26nWWcON2w08tvGFvzdOZorLPM= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-331-tIPy53fuMYG3RUeHoF4z6A-1; Mon, 09 Nov 2026 11:45:48 -0500 X-MC-Unique: tIPy53fuMYG3RUeHoF4z6A-1 X-Mimecast-MFC-AGG-ID: tIPy53fuMYG3RUeHoF4z6A_1794242747 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (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 mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 20D201955DBE; Mon, 9 Nov 2026 16:45:47 +0000 (UTC) Received: from merkur.fritz.box (unknown [10.44.32.41]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id C495E30000E5; Mon, 9 Nov 2026 16:45:45 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Cc: kwolf@redhat.com, richard.henderson@linaro.org, qemu-devel@nongnu.org Subject: [PULL 05/11] block/vmdk: Reject a zero cluster_sectors parameter Date: Mon, 9 Nov 2026 17:45:27 +0100 Message-ID: <20261109164533.293487-6-kwolf@redhat.com> In-Reply-To: <20261109164533.293487-1-kwolf@redhat.com> References: <20261109164533.293487-1-kwolf@redhat.com> X-Archived-By: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Received-SPF: pass client-ip=170.10.129.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 5 X-Spam_score: 0.5 X-Spam_bar: / X-Spam_report: (0.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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, RCVD_IN_SBL_CSS=3.335, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org X-Spam-Status: No, score=-20.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_PASS,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 From: Peter Maydell In vmdk_add_extent() we reject image files with an excessively large cluster_sectors parameter, but have no lower bound. In particular, if the cluster_sectors is 0 then we will set l1_entry_sectors also to 0, and later crash with a SIGFPE for division by zero. Reject a zero cluster_sectors value, unless this is a flat extent (in which case cluster_sectors isn't relevant and the callsite always passes us zero). The worst case here is a self-denial-of-service with a QEMU crash, so this is a hardening bug. Cc: qemu-stable@nongnu.org Fixes: b3976d3c8b89 ("VMDK: introduce VmdkExtent") Reported-by: Tristan Resolves: https://gitlab.com/qemu-project/qemu/-/work_items/4017 Signed-off-by: Peter Maydell Message-ID: <20261103143516.2182626-5-peter.maydell@linaro.org> Reviewed-by: Kevin Wolf Signed-off-by: Kevin Wolf --- block/vmdk.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/block/vmdk.c b/block/vmdk.c index bd18d32085f..d7e23ae8098 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -552,6 +552,11 @@ static int vmdk_add_extent(BlockDriverState *bs, BDRVVmdkState *s = bs->opaque; int64_t nb_sectors; + if (!flat && cluster_sectors == 0) { + error_setg(errp, "Invalid zero granularity, image may be corrupt"); + return -EINVAL; + } + if (cluster_sectors > 0x200000) { /* 0x200000 * 512Bytes = 1GB for one cluster is unrealistic */ error_setg(errp, "Invalid granularity, image may be corrupt"); -- 2.56.0