From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AA949CCA47B for ; Mon, 11 Jul 2022 09:48:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233137AbiGKJr7 (ORCPT ); Mon, 11 Jul 2022 05:47:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48162 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233617AbiGKJrc (ORCPT ); Mon, 11 Jul 2022 05:47:32 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 35CC65C955; Mon, 11 Jul 2022 02:23:08 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id B04ADB80E6D; Mon, 11 Jul 2022 09:23:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0CE56C34115; Mon, 11 Jul 2022 09:23:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1657531385; bh=3cja/hQNCOn4PAFMjDouotW5Db/OIZC/dXKK3WM6m0M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2Tfmm++Cn493USQc/yHmaPTzwLwLxI35ewBJ2B3zhj44htUMC5ktAEMJGYvyFoGiI +WF/gqOw6uaNP6dHqKhK3hvg3T5ZwQpt0UTkJ1gPHh0lQxCt/WKRLpKIKr1LDQkUJ4 lgX5O5L7I1Rl4zLA+cYjPpflR0Jejh2kr9e9aih0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eli Cohen , "Michael S. Tsirkin" , Sasha Levin Subject: [PATCH 5.15 084/230] vdpa/mlx5: Avoid processing works if workqueue was destroyed Date: Mon, 11 Jul 2022 11:05:40 +0200 Message-Id: <20220711090606.456720798@linuxfoundation.org> X-Mailer: git-send-email 2.37.0 In-Reply-To: <20220711090604.055883544@linuxfoundation.org> References: <20220711090604.055883544@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eli Cohen [ Upstream commit ad6dc1daaf29f97f23cc810d60ee01c0e83f4c6b ] If mlx5_vdpa gets unloaded while a VM is running, the workqueue will be destroyed. However, vhost might still have reference to the kick function and might attempt to push new works. This could lead to null pointer dereference. To fix this, set mvdev->wq to NULL just before destroying and verify that the workqueue is not NULL in mlx5_vdpa_kick_vq before attempting to push a new work. Fixes: 5262912ef3cf ("vdpa/mlx5: Add support for control VQ and MAC setting") Signed-off-by: Eli Cohen Link: https://lore.kernel.org/r/20220321141303.9586-1-elic@nvidia.com Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin --- drivers/vdpa/mlx5/net/mlx5_vnet.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c index 174895372e7f..467a349dc26c 100644 --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c @@ -1641,7 +1641,7 @@ static void mlx5_vdpa_kick_vq(struct vdpa_device *vdev, u16 idx) return; if (unlikely(is_ctrl_vq_idx(mvdev, idx))) { - if (!mvdev->cvq.ready) + if (!mvdev->wq || !mvdev->cvq.ready) return; queue_work(mvdev->wq, &ndev->cvq_ent.work); @@ -2626,9 +2626,12 @@ static void mlx5_vdpa_dev_del(struct vdpa_mgmt_dev *v_mdev, struct vdpa_device * struct mlx5_vdpa_mgmtdev *mgtdev = container_of(v_mdev, struct mlx5_vdpa_mgmtdev, mgtdev); struct mlx5_vdpa_dev *mvdev = to_mvdev(dev); struct mlx5_vdpa_net *ndev = to_mlx5_vdpa_ndev(mvdev); + struct workqueue_struct *wq; mlx5_notifier_unregister(mvdev->mdev, &ndev->nb); - destroy_workqueue(mvdev->wq); + wq = mvdev->wq; + mvdev->wq = NULL; + destroy_workqueue(wq); _vdpa_unregister_device(dev); mgtdev->ndev = NULL; } -- 2.35.1