From nobody Sat Jul 25 09:25:25 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=1784641519; cv=none; d=zohomail.com; s=zohoarc; b=OIZZWJI818Zio12o0/kDCV+VeYPvaTHmPM/tDK8JWORJ1WFLtOXOcpm2Gp8/ZzeQQNHEpbyuNHUh5FCNyqRYp54n2gtEycO1oOcjkjqZq4G0K99ErMUayF+uHp9z3cwMWmda5Chzr9LN+9uJ8xiJvCxHn7LRuEwcVwR5zUx5ECE= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1784641519; 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=Cx8vLMJg9zXjhYyWKskgl/CVpCD47uOslPzrLgIp52M=; b=Ec7RXokS5h23lPfIyd69M8SkanUkUpdhcI9fiUOIgKIBeaFEORNV+kS09vzoGuoHjMG+wycyZycNgXtci1jyLi2y90rrL5xcZChofKiI6E9ZIWb22Ou8F6vSF8ltuOMyYtQVoohUvrjM5iH/xUpmP/MEWp8qv6VGmsE160ixEoE= 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 1784641519400723.1682013117261; Tue, 21 Jul 2026 06:45:19 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1wmAm4-0000n9-9k; Tue, 21 Jul 2026 09:44:44 -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 1wmAlz-0000cp-0F for qemu-devel@nongnu.org; Tue, 21 Jul 2026 09:44:40 -0400 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 1wmAlw-0001UP-4c for qemu-devel@nongnu.org; Tue, 21 Jul 2026 09:44:38 -0400 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-357-KKDI551uMEmXrxSTtl1wVQ-1; Tue, 21 Jul 2026 09:44:28 -0400 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 B98CC195F17D; Tue, 21 Jul 2026 13:44:27 +0000 (UTC) Received: from localhost (unknown [10.2.16.155]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id E36F73003EFD; Tue, 21 Jul 2026 13:44:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1784641472; 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=Cx8vLMJg9zXjhYyWKskgl/CVpCD47uOslPzrLgIp52M=; b=dT4tfyOn4CtjVVbVzIxd8c/YNiLoaH/KH5r7Jx4apgqH+xVLpx9LSw9jkp5VpjQjUwn2zB J2bCS7JXnMYbVWAKtgdQlLQ7EDDbdRLbNjcO+QFWw3fmUxdW8ztcjhKdKAiG2bCuuOymFT 93MDog3ZIa3hf3MTBkJyY1fZxI+ezeI= X-MC-Unique: KKDI551uMEmXrxSTtl1wVQ-1 X-Mimecast-MFC-AGG-ID: KKDI551uMEmXrxSTtl1wVQ_1784641467 From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: "Michael S. Tsirkin" , Stefan Hajnoczi , Anatol Belski Subject: [PATCH for-11.1] virtio: avoid packed vring virtio_queue_empty() infinite loops (CVE-2026-16457) Date: Tue, 21 Jul 2026 09:44:24 -0400 Message-ID: <20260721134424.196337-1-stefanha@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 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=170.10.129.124; envelope-from=stefanha@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_H2=-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: 1784641521246158500 Content-Type: text/plain; charset="utf-8" Virtqueue handler functions in device emulation code often look something like this: while (!virtio_queue_empty(vq)) { ...pop and process virtqueue element... } virtio-blk, virtio-scsi, virtio-crypto, and vhost-shadow-virtqueue use this pattern. The device may break (i.e. hit an error that requires device reset) during the loop. virtio_queue_empty() returns 1 for broken split vrings but not for broken packed vrings, leading to an infinite loop. Adjust the packed vring behavior to match split vrings and avoid infinite loops. Fixes: CVE-2026-16457 Resolves: https://gitlab.com/qemu-project/qemu/-/work_items/3968 Reported-by: Anatol Belski Signed-off-by: Stefan Hajnoczi Reviewed-by: Philippe Mathieu-Daud=C3=A9 --- hw/virtio/virtio.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index f4d86a36553..3795e3c8c68 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -763,6 +763,10 @@ static int virtio_queue_packed_empty_rcu(VirtQueue *vq) struct VRingPackedDesc desc; VRingMemoryRegionCaches *cache; =20 + if (virtio_device_disabled(vq->vdev)) { + return 1; + } + if (unlikely(!vq->vring.desc)) { return 1; } --=20 2.55.0