From patchwork Thu Jan 6 12:42:08 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wen Gu X-Patchwork-Id: 12705386 X-Patchwork-Delegate: kuba@kernel.org 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 97CCAC433FE for ; Thu, 6 Jan 2022 12:42:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238979AbiAFMmS (ORCPT ); Thu, 6 Jan 2022 07:42:18 -0500 Received: from out30-57.freemail.mail.aliyun.com ([115.124.30.57]:46055 "EHLO out30-57.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238945AbiAFMmS (ORCPT ); Thu, 6 Jan 2022 07:42:18 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R101e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04423;MF=guwen@linux.alibaba.com;NM=1;PH=DS;RN=6;SR=0;TI=SMTPD_---0V16OO3w_1641472929; Received: from e02h04404.eu6sqa(mailfrom:guwen@linux.alibaba.com fp:SMTPD_---0V16OO3w_1641472929) by smtp.aliyun-inc.com(127.0.0.1); Thu, 06 Jan 2022 20:42:16 +0800 From: Wen Gu To: kgraul@linux.ibm.com, davem@davemloft.net, kuba@kernel.org Cc: linux-s390@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net v5] net/smc: Reset conn->lgr when link group registration fails Date: Thu, 6 Jan 2022 20:42:08 +0800 Message-Id: <1641472928-55944-1-git-send-email-guwen@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org SMC connections might fail to be registered in a link group due to unable to find a usable link during its creation. As a result, smc_conn_create() will return a failure and most resources related to the connection won't be applied or initialized, such as conn->abort_work or conn->lnk. If smc_conn_free() is invoked later, it will try to access the uninitialized resources related to the connection, thus causing a warning or crash. This patch tries to fix this by resetting conn->lgr to NULL if an abnormal exit occurs in smc_lgr_register_conn(), thus avoiding the access to uninitialized resources in smc_conn_free(). Meanwhile, the new created link group should be terminated if smc connections can't be registered in it. So smc_lgr_cleanup_early() is modified to take care of link group only and invoked to terminate unusable link group by smc_conn_create(). The call to smc_conn_free() is moved out from smc_lgr_cleanup_early() to smc_conn_abort(). Fixes: 56bc3b2094b4 ("net/smc: assign link to a new connection") Suggested-by: Karsten Graul Signed-off-by: Wen Gu Acked-by: Karsten Graul --- v1->v2: - Reset conn->lgr to NULL in smc_lgr_register_conn(). - Only free new created link group. v2->v3: - Using __smc_lgr_terminate() instead of smc_lgr_schedule_free_work() for an immediate free. v3->v4: - Modify smc_lgr_cleanup_early() and invoke it from smc_conn_create(). v4->v5: - Hold a local copy of lgr in smc_conn_abort(). --- net/smc/af_smc.c | 8 +++++--- net/smc/smc_core.c | 12 +++++++----- net/smc/smc_core.h | 2 +- 3 files changed, 13 insertions(+), 9 deletions(-) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index 230072f..e244b88 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -630,10 +630,12 @@ static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code, static void smc_conn_abort(struct smc_sock *smc, int local_first) { + struct smc_connection *conn = &smc->conn; + struct smc_link_group *lgr = conn->lgr; + + smc_conn_free(conn); if (local_first) - smc_lgr_cleanup_early(&smc->conn); - else - smc_conn_free(&smc->conn); + smc_lgr_cleanup_early(lgr); } /* check if there is a rdma device available for this connection. */ diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index a684936..c9a8092 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -171,8 +171,10 @@ static int smc_lgr_register_conn(struct smc_connection *conn, bool first) if (!conn->lgr->is_smcd) { rc = smcr_lgr_conn_assign_link(conn, first); - if (rc) + if (rc) { + conn->lgr = NULL; return rc; + } } /* find a new alert_token_local value not yet used by some connection * in this link group @@ -622,15 +624,13 @@ int smcd_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb) return skb->len; } -void smc_lgr_cleanup_early(struct smc_connection *conn) +void smc_lgr_cleanup_early(struct smc_link_group *lgr) { - struct smc_link_group *lgr = conn->lgr; spinlock_t *lgr_lock; if (!lgr) return; - smc_conn_free(conn); smc_lgr_list_head(lgr, &lgr_lock); spin_lock_bh(lgr_lock); /* do not use this link group for new connections */ @@ -1832,8 +1832,10 @@ int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini) write_lock_bh(&lgr->conns_lock); rc = smc_lgr_register_conn(conn, true); write_unlock_bh(&lgr->conns_lock); - if (rc) + if (rc) { + smc_lgr_cleanup_early(lgr); goto out; + } } conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE; conn->local_tx_ctrl.len = SMC_WR_TX_SIZE; diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h index d63b082..73d0c35 100644 --- a/net/smc/smc_core.h +++ b/net/smc/smc_core.h @@ -468,7 +468,7 @@ static inline void smc_set_pci_values(struct pci_dev *pci_dev, struct smc_sock; struct smc_clc_msg_accept_confirm; -void smc_lgr_cleanup_early(struct smc_connection *conn); +void smc_lgr_cleanup_early(struct smc_link_group *lgr); void smc_lgr_terminate_sched(struct smc_link_group *lgr); void smcr_port_add(struct smc_ib_device *smcibdev, u8 ibport); void smcr_port_err(struct smc_ib_device *smcibdev, u8 ibport);