From nobody Wed Nov 19 20:20:24 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; 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 Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1702383658987615.9085601550049; Tue, 12 Dec 2023 04:20:58 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rD1jP-0005G3-Tc; Tue, 12 Dec 2023 07:19:24 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rD1jO-0005Es-0k; Tue, 12 Dec 2023 07:19:22 -0500 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rD1jA-0000IF-OY; Tue, 12 Dec 2023 07:19:21 -0500 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 20CCC3AEF8; Tue, 12 Dec 2023 15:18:49 +0300 (MSK) Received: from tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with SMTP id D9B0F3B946; Tue, 12 Dec 2023 15:18:31 +0300 (MSK) Received: (nullmailer pid 1003413 invoked by uid 1000); Tue, 12 Dec 2023 12:18:31 -0000 From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Akihiko Odaki , Alexander Bulekov , Jason Wang , Michael Tokarev Subject: [Stable-8.1.4 05/31] net: Update MemReentrancyGuard for NIC Date: Tue, 12 Dec 2023 15:17:53 +0300 Message-Id: <20231212121831.1003318-5-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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=lists.gnu.org; Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, 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: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1702383659692100005 Content-Type: text/plain; charset="utf-8" From: Akihiko Odaki Recently MemReentrancyGuard was added to DeviceState to record that the device is engaging in I/O. The network device backend needs to update it when delivering a packet to a device. This implementation follows what bottom half does, but it does not add a tracepoint for the case that the network device backend started delivering a packet to a device which is already engaging in I/O. This is because such reentrancy frequently happens for qemu_flush_queued_packets() and is insignificant. Fixes: CVE-2023-3019 Reported-by: Alexander Bulekov Signed-off-by: Akihiko Odaki Acked-by: Alexander Bulekov Signed-off-by: Jason Wang (cherry picked from commit 9050f976e447444ea6ee2ba12c9f77e4b0dc54bc) Signed-off-by: Michael Tokarev diff --git a/include/net/net.h b/include/net/net.h index a7d8deaccb..685ec58318 100644 --- a/include/net/net.h +++ b/include/net/net.h @@ -124,6 +124,7 @@ typedef QTAILQ_HEAD(NetClientStateList, NetClientState)= NetClientStateList; typedef struct NICState { NetClientState *ncs; NICConf *conf; + MemReentrancyGuard *reentrancy_guard; void *opaque; bool peer_deleted; } NICState; diff --git a/net/net.c b/net/net.c index 982df2479f..3523cceafc 100644 --- a/net/net.c +++ b/net/net.c @@ -332,6 +332,7 @@ NICState *qemu_new_nic(NetClientInfo *info, nic =3D g_malloc0(info->size + sizeof(NetClientState) * queues); nic->ncs =3D (void *)nic + info->size; nic->conf =3D conf; + nic->reentrancy_guard =3D reentrancy_guard, nic->opaque =3D opaque; =20 for (i =3D 0; i < queues; i++) { @@ -805,6 +806,7 @@ static ssize_t qemu_deliver_packet_iov(NetClientState *= sender, int iovcnt, void *opaque) { + MemReentrancyGuard *owned_reentrancy_guard; NetClientState *nc =3D opaque; int ret; =20 @@ -817,12 +819,24 @@ static ssize_t qemu_deliver_packet_iov(NetClientState= *sender, return 0; } =20 + if (nc->info->type !=3D NET_CLIENT_DRIVER_NIC || + qemu_get_nic(nc)->reentrancy_guard->engaged_in_io) { + owned_reentrancy_guard =3D NULL; + } else { + owned_reentrancy_guard =3D qemu_get_nic(nc)->reentrancy_guard; + owned_reentrancy_guard->engaged_in_io =3D true; + } + if (nc->info->receive_iov && !(flags & QEMU_NET_PACKET_FLAG_RAW)) { ret =3D nc->info->receive_iov(nc, iov, iovcnt); } else { ret =3D nc_sendv_compat(nc, iov, iovcnt, flags); } =20 + if (owned_reentrancy_guard) { + owned_reentrancy_guard->engaged_in_io =3D false; + } + if (ret =3D=3D 0) { nc->receive_disabled =3D 1; } --=20 2.39.2