From nobody Sat Jul 25 17:35:17 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=quarantine dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1784116286; cv=none; d=zohomail.com; s=zohoarc; b=EIgvs+CfYy5MmT494EVMGzpiGnWwfVD18pVdDZnR3YW1hAKke0TJCMlLGzeMnaQnlLIsXj6XbYDtSw7ErlsCMPi+VVy9SZhuus0xQdNLdk5xDGCBg53N/a2Vgca3OwG2K2qE3mbFhFZ2Jy4tEL3V2Bly/ACHsscJvf6pmXonCEk= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1784116286; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Sender:Subject:Subject:To:To:Message-Id:Reply-To; bh=iBkS4SONdzYHjteBaBsxoOo8C76vZJfa+IvjxQCZ5j4=; b=hqP8X5Kl3NYZBVhZcNYlvTdBOyX9y6Qj5NrU2ksI2xOfIp5cg/8UrFDtLPNHOY6YmIotBWg2SZuuPHHlftSp5J2tcf4RRhLQaRoGqmSzttPbDDNSQT4N6F/bvydYZ4eTuNprxZ0WutuUjp7iw2FeCfB5SYdjc3wSPHXNocoTvgM= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=quarantine dis=none) Return-Path: Received: from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 178411628618413.609562873482105; Wed, 15 Jul 2026 04:51:26 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1wjy8c-0000Np-L1; Wed, 15 Jul 2026 07:50:54 -0400 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 1wjy8a-0000NJ-SS for qemu-devel@nongnu.org; Wed, 15 Jul 2026 07:50:52 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wjy8Y-0006IH-TZ for qemu-devel@nongnu.org; Wed, 15 Jul 2026 07:50:52 -0400 Received: from mx-prod-mc-03.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-344-mKQd3PWuNka5h6HJBh8dTA-1; Wed, 15 Jul 2026 07:50:45 -0400 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (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-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id E754C1956061; Wed, 15 Jul 2026 11:50:43 +0000 (UTC) Received: from lenovo-t14s.redhat.corp (headnet04.pony-001.prod.iad2.dc.redhat.com [10.2.32.116]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 30A32180036E; Wed, 15 Jul 2026 11:50:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1784116250; 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; bh=iBkS4SONdzYHjteBaBsxoOo8C76vZJfa+IvjxQCZ5j4=; b=bWQq7S8T6KQzSfSNirTv/J6OHbvCWQ6zmWwxeNqWGV8HOAxfTVW+LV0Z6QYCTrtBIBZ7l9 uO7nKkMnlMDMIc+Mn6FVBMPxeJkdQF18Mb+JJxTIt4o26mtqnyHhCW8LUkbiYa21++EqUs ski7Xys+i1sTFgoR+Q6HHwsGnFSRnu0= X-MC-Unique: mKQd3PWuNka5h6HJBh8dTA-1 X-Mimecast-MFC-AGG-ID: mKQd3PWuNka5h6HJBh8dTA_1784116244 From: Laurent Vivier To: qemu-devel@nongnu.org Cc: "Michael S. Tsirkin" , Laurent Vivier , jasowangio@gmail.com, qemu-stable@nongnu.org Subject: [PATCH] hw/virtio: reject zero-length packed indirect descriptor table Date: Wed, 15 Jul 2026 13:50:40 +0200 Message-ID: <20260715115040.2186274-1-lvivier@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists1p.gnu.org; Received-SPF: permerror client-ip=170.10.133.124; envelope-from=lvivier@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 12 X-Spam_score: 1.2 X-Spam_bar: + X-Spam_report: (1.2 / 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_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, RCVD_IN_SBL_CSS=3.335, SPF_HELO_PASS=-0.001, T_SPF_PERMERROR=0.01 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-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @redhat.com) X-ZM-MESSAGEID: 1784116288824158500 Content-Type: text/plain; charset="utf-8" The split-ring path already rejects a zero-length indirect descriptor table since commit 7423192912af ("virtio: add checks for the size of the indirect table"). The packed-ring path is missing the same check, allowing a guest to trigger an assertion in address_space_cache_init() with a packed indirect descriptor that has len=3D0. Add the same !desc.len check to the packed-ring indirect validation in both virtqueue_packed_get_avail_bytes() and virtqueue_packed_pop(). Fixes: 86044b24e865 ("virtio: basic packed virtqueue support") Cc: jasowangio@gmail.com Cc: qemu-stable@nongnu.org Resolves: https://gitlab.com/qemu-project/qemu/-/issues/3984 Signed-off-by: Laurent Vivier --- hw/virtio/virtio.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index f4d86a365530..1b86c7f41fa8 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -1475,7 +1475,7 @@ static void virtqueue_packed_get_avail_bytes(VirtQueu= e *vq, } =20 if (desc.flags & VRING_DESC_F_INDIRECT) { - if (desc.len % sizeof(VRingPackedDesc)) { + if (!desc.len || (desc.len % sizeof(VRingPackedDesc))) { virtio_error(vdev, "Invalid size for indirect buffer table= "); goto err; } @@ -1927,7 +1927,7 @@ static void *virtqueue_packed_pop(VirtQueue *vq, size= _t sz) vring_packed_desc_read(vdev, &desc, desc_cache, i, true); id =3D desc.id; if (desc.flags & VRING_DESC_F_INDIRECT) { - if (desc.len % sizeof(VRingPackedDesc)) { + if (!desc.len || (desc.len % sizeof(VRingPackedDesc))) { virtio_error(vdev, "Invalid size for indirect buffer table"); goto done; } --=20 2.54.0