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 X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 620BEC4332B for ; Mon, 28 Dec 2020 14:09:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2C617207A9 for ; Mon, 28 Dec 2020 14:09:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2438786AbgL1OJL (ORCPT ); Mon, 28 Dec 2020 09:09:11 -0500 Received: from mail.kernel.org ([198.145.29.99]:43352 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2438776AbgL1OJI (ORCPT ); Mon, 28 Dec 2020 09:09:08 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id B1A88206E5; Mon, 28 Dec 2020 14:08:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609164533; bh=qBGylRh7ELqSRZd0Q54qLZPjhjZWbDHUUKNBEPJQRJQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=szhWcHPE9CLY1XbTlxz9qI5+JBDggICGM/iXjwA3jtmcfc0m4Y6L3TN47TetRkcRq TP02EIpTCN5nF7+nClG2JL+/DMMesZ5NFx7El+sxiFr+HsXDoiLeP/f6lchEqPac3P hjwgsmAwlJmgcHiSjiwlJmiV/xe6fp8B7aOdK77s= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+1bc48bf7f78253f664a9@syzkaller.appspotmail.com, Leon Romanovsky , Jason Gunthorpe , Sasha Levin Subject: [PATCH 5.10 207/717] RDMA/cma: Fix deadlock on &lock in rdma_cma_listen_on_all() error unwind Date: Mon, 28 Dec 2020 13:43:25 +0100 Message-Id: <20201228125030.896722377@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201228125020.963311703@linuxfoundation.org> References: <20201228125020.963311703@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: linux-kernel@vger.kernel.org From: Jason Gunthorpe [ Upstream commit dd37d2f59eb839d51b988f6668ce5f0d533b23fd ] rdma_detroy_id() cannot be called under &lock - we must instead keep the error'd ID around until &lock can be released, then destroy it. This is complicated by the usual way listen IDs are destroyed through cma_process_remove() which can run at any time and will asynchronously destroy the same ID. Remove the ID from visiblity of cma_process_remove() before going down the destroy path outside the locking. Fixes: c80a0c52d85c ("RDMA/cma: Add missing error handling of listen_id") Link: https://lore.kernel.org/r/20201118133756.GK244516@ziepe.ca Reported-by: syzbot+1bc48bf7f78253f664a9@syzkaller.appspotmail.com Reviewed-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin --- drivers/infiniband/core/cma.c | 25 ++++++++++++++++++------- 1 file changed, 18 insertions(+), 7 deletions(-) diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c index 4585f654f8836..c06c87a4dc5e7 100644 --- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -2496,7 +2496,8 @@ static int cma_listen_handler(struct rdma_cm_id *id, } static int cma_listen_on_dev(struct rdma_id_private *id_priv, - struct cma_device *cma_dev) + struct cma_device *cma_dev, + struct rdma_id_private **to_destroy) { struct rdma_id_private *dev_id_priv; struct net *net = id_priv->id.route.addr.dev_addr.net; @@ -2504,6 +2505,7 @@ static int cma_listen_on_dev(struct rdma_id_private *id_priv, lockdep_assert_held(&lock); + *to_destroy = NULL; if (cma_family(id_priv) == AF_IB && !rdma_cap_ib_cm(cma_dev->device, 1)) return 0; @@ -2518,7 +2520,6 @@ static int cma_listen_on_dev(struct rdma_id_private *id_priv, rdma_addr_size(cma_src_addr(id_priv))); _cma_attach_to_dev(dev_id_priv, cma_dev); - list_add_tail(&dev_id_priv->listen_list, &id_priv->listen_list); cma_id_get(id_priv); dev_id_priv->internal_id = 1; dev_id_priv->afonly = id_priv->afonly; @@ -2528,25 +2529,31 @@ static int cma_listen_on_dev(struct rdma_id_private *id_priv, ret = rdma_listen(&dev_id_priv->id, id_priv->backlog); if (ret) goto err_listen; + list_add_tail(&dev_id_priv->listen_list, &id_priv->listen_list); return 0; err_listen: - list_del(&id_priv->listen_list); + /* Caller must destroy this after releasing lock */ + *to_destroy = dev_id_priv; dev_warn(&cma_dev->device->dev, "RDMA CMA: %s, error %d\n", __func__, ret); - rdma_destroy_id(&dev_id_priv->id); return ret; } static int cma_listen_on_all(struct rdma_id_private *id_priv) { + struct rdma_id_private *to_destroy; struct cma_device *cma_dev; int ret; mutex_lock(&lock); list_add_tail(&id_priv->list, &listen_any_list); list_for_each_entry(cma_dev, &dev_list, list) { - ret = cma_listen_on_dev(id_priv, cma_dev); - if (ret) + ret = cma_listen_on_dev(id_priv, cma_dev, &to_destroy); + if (ret) { + /* Prevent racing with cma_process_remove() */ + if (to_destroy) + list_del_init(&to_destroy->list); goto err_listen; + } } mutex_unlock(&lock); return 0; @@ -2554,6 +2561,8 @@ static int cma_listen_on_all(struct rdma_id_private *id_priv) err_listen: list_del(&id_priv->list); mutex_unlock(&lock); + if (to_destroy) + rdma_destroy_id(&to_destroy->id); return ret; } @@ -4855,6 +4864,7 @@ static void cma_process_remove(struct cma_device *cma_dev) static int cma_add_one(struct ib_device *device) { + struct rdma_id_private *to_destroy; struct cma_device *cma_dev; struct rdma_id_private *id_priv; unsigned int i; @@ -4902,7 +4912,7 @@ static int cma_add_one(struct ib_device *device) mutex_lock(&lock); list_add_tail(&cma_dev->list, &dev_list); list_for_each_entry(id_priv, &listen_any_list, list) { - ret = cma_listen_on_dev(id_priv, cma_dev); + ret = cma_listen_on_dev(id_priv, cma_dev, &to_destroy); if (ret) goto free_listen; } @@ -4915,6 +4925,7 @@ free_listen: list_del(&cma_dev->list); mutex_unlock(&lock); + /* cma_process_remove() will delete to_destroy */ cma_process_remove(cma_dev); kfree(cma_dev->default_roce_tos); free_gid_type: -- 2.27.0