From patchwork Thu Sep 27 12:22:04 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Wang X-Patchwork-Id: 10617953 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F0B24174A for ; Thu, 27 Sep 2018 12:22:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E18102B2DA for ; Thu, 27 Sep 2018 12:22:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DFF852B38F; Thu, 27 Sep 2018 12:22:21 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 80AE42B2F1 for ; Thu, 27 Sep 2018 12:22:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727469AbeI0SkQ (ORCPT ); Thu, 27 Sep 2018 14:40:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42352 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727199AbeI0SkQ (ORCPT ); Thu, 27 Sep 2018 14:40:16 -0400 Received: from smtp.corp.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B978B81107; Thu, 27 Sep 2018 12:22:14 +0000 (UTC) Received: from jason-ThinkPad-T450s.redhat.com (ovpn-12-27.pek2.redhat.com [10.72.12.27]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1D2CCBF9B1; Thu, 27 Sep 2018 12:22:06 +0000 (UTC) From: Jason Wang To: stefanha@redhat.com, mst@redhat.com Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, sergei.shtylyov@cogentembedded.com, Jason Wang Subject: [PATCH net V2] vhost-vsock: fix use after free Date: Thu, 27 Sep 2018 20:22:04 +0800 Message-Id: <20180927122204.4188-1-jasowang@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.27 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Thu, 27 Sep 2018 12:22:14 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The access of vsock is not protected by vhost_vsock_lock. This may lead to use after free since vhost_vsock_dev_release() may free the pointer at the same time. Fix this by holding the lock during the access. Reported-by: syzbot+e3e074963495f92a89ed@syzkaller.appspotmail.com Fixes: 16320f363ae1 ("vhost-vsock: add pkt cancel capability") Fixes: 433fc58e6bf2 ("VSOCK: Introduce vhost_vsock.ko") Cc: Stefan Hajnoczi Signed-off-by: Jason Wang Reviewed-by: Stefan Hajnoczi --- - V2: fix typos - The patch is needed for -stable. --- drivers/vhost/vsock.c | 26 +++++++++++++++++++------- 1 file changed, 19 insertions(+), 7 deletions(-) diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index 34bc3ab40c6d..7d0b292867fd 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -210,21 +210,27 @@ vhost_transport_send_pkt(struct virtio_vsock_pkt *pkt) struct vhost_vsock *vsock; int len = pkt->len; + spin_lock_bh(&vhost_vsock_lock); + /* Find the vhost_vsock according to guest context id */ - vsock = vhost_vsock_get(le64_to_cpu(pkt->hdr.dst_cid)); + vsock = __vhost_vsock_get(le64_to_cpu(pkt->hdr.dst_cid)); if (!vsock) { virtio_transport_free_pkt(pkt); + spin_unlock_bh(&vhost_vsock_lock); return -ENODEV; } if (pkt->reply) atomic_inc(&vsock->queued_replies); - spin_lock_bh(&vsock->send_pkt_list_lock); + spin_lock(&vsock->send_pkt_list_lock); list_add_tail(&pkt->list, &vsock->send_pkt_list); - spin_unlock_bh(&vsock->send_pkt_list_lock); + spin_unlock(&vsock->send_pkt_list_lock); vhost_work_queue(&vsock->dev, &vsock->send_pkt_work); + + spin_unlock_bh(&vhost_vsock_lock); + return len; } @@ -236,18 +242,22 @@ vhost_transport_cancel_pkt(struct vsock_sock *vsk) int cnt = 0; LIST_HEAD(freeme); + spin_lock_bh(&vhost_vsock_lock); + /* Find the vhost_vsock according to guest context id */ - vsock = vhost_vsock_get(vsk->remote_addr.svm_cid); - if (!vsock) + vsock = __vhost_vsock_get(vsk->remote_addr.svm_cid); + if (!vsock) { + spin_unlock_bh(&vhost_vsock_lock); return -ENODEV; + } - spin_lock_bh(&vsock->send_pkt_list_lock); + spin_lock(&vsock->send_pkt_list_lock); list_for_each_entry_safe(pkt, n, &vsock->send_pkt_list, list) { if (pkt->vsk != vsk) continue; list_move(&pkt->list, &freeme); } - spin_unlock_bh(&vsock->send_pkt_list_lock); + spin_unlock(&vsock->send_pkt_list_lock); list_for_each_entry_safe(pkt, n, &freeme, list) { if (pkt->reply) @@ -265,6 +275,8 @@ vhost_transport_cancel_pkt(struct vsock_sock *vsk) vhost_poll_queue(&tx_vq->poll); } + spin_unlock_bh(&vhost_vsock_lock); + return 0; }