From patchwork Fri Nov 22 07:16:30 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wen Gu X-Patchwork-Id: 13882812 X-Patchwork-Delegate: kuba@kernel.org Received: from out30-118.freemail.mail.aliyun.com (out30-118.freemail.mail.aliyun.com [115.124.30.118]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3343616BE01; Fri, 22 Nov 2024 07:16:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.118 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732259807; cv=none; b=gIKPNhyD1PinyPRc52QTGPobIanvfIzZjt6685ewBnJkh/kfaNufDxXjvKJccRswALR9SaPUWNRLwST4ecoooYwxc3dnWNxmDgCgb9OtS+HdcxW2nhbb2gsWinWd470vGnCGq5U0ytFP2gpTEFuo3TtTp9RHtOTvhkdb2Trcguw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732259807; c=relaxed/simple; bh=2cSQxrteySvr13xOvnwTvI9SQX8fC71lvBVAvXlndMM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=LW2J8syc8VxN7ITpdFUg2Mtukbgx1ZKmxVrzYw+MC3FrD0T1wZmBvvppyITo2j/04E2AgzY7z83FYbFHUMKdrhG3k4qhlHNJ64Yl560HFke9aorrdbZduEopu2T+VUnbssqAK4cwQX0nZjonDdzbRhIurenpyM51w6EyBKux6f4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=KbmIKtKr; arc=none smtp.client-ip=115.124.30.118 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="KbmIKtKr" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1732259796; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=ijdPFqMJEXQyY7cj+GbQC+Q1McJItiVYA1uEbryR+DM=; b=KbmIKtKrUjbelgN1+PZrVTI5HbgPeId/UAeBaJo998/EmwUhWxFUGOaxqL5SPSBrcucoU5iystuQgQ88dOTZGghWAqFhFq6mc0l8lvGfjacBtZ17XxYjKjYEm3963E5jXskt8zttdv0jrmUMsRRBeN4HTf6MGJSnyI+xQUWGreI= Received: from localhost(mailfrom:guwen@linux.alibaba.com fp:SMTPD_---0WJzhgeP_1732259794 cluster:ay36) by smtp.aliyun-inc.com; Fri, 22 Nov 2024 15:16:35 +0800 From: Wen Gu To: wenjia@linux.ibm.com, jaka@linux.ibm.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com Cc: alibuda@linux.alibaba.com, tonylu@linux.alibaba.com, guwen@linux.alibaba.com, horms@kernel.org, linux-rdma@vger.kernel.org, linux-s390@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net 2/2] net/smc: fix LGR and link use-after-free issue Date: Fri, 22 Nov 2024 15:16:30 +0800 Message-Id: <20241122071630.63707-3-guwen@linux.alibaba.com> X-Mailer: git-send-email 2.32.0.3.g01195cf9f In-Reply-To: <20241122071630.63707-1-guwen@linux.alibaba.com> References: <20241122071630.63707-1-guwen@linux.alibaba.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org We encountered a LGR/link use-after-free issue, which manifested as the LGR/link refcnt reaching 0 early and entering the clear process, making resource access unsafe. refcount_t: addition on 0; use-after-free. WARNING: CPU: 14 PID: 107447 at lib/refcount.c:25 refcount_warn_saturate+0x9c/0x140 Workqueue: events smc_lgr_terminate_work [smc] Call trace: refcount_warn_saturate+0x9c/0x140 __smc_lgr_terminate.part.45+0x2a8/0x370 [smc] smc_lgr_terminate_work+0x28/0x30 [smc] process_one_work+0x1b8/0x420 worker_thread+0x158/0x510 kthread+0x114/0x118 or refcount_t: underflow; use-after-free. WARNING: CPU: 6 PID: 93140 at lib/refcount.c:28 refcount_warn_saturate+0xf0/0x140 Workqueue: smc_hs_wq smc_listen_work [smc] Call trace: refcount_warn_saturate+0xf0/0x140 smcr_link_put+0x1cc/0x1d8 [smc] smc_conn_free+0x110/0x1b0 [smc] smc_conn_abort+0x50/0x60 [smc] smc_listen_find_device+0x75c/0x790 [smc] smc_listen_work+0x368/0x8a0 [smc] process_one_work+0x1b8/0x420 worker_thread+0x158/0x510 kthread+0x114/0x118 It is caused by repeated release of LGR/link refcnt. One suspect is that smc_conn_free() is called repeatedly because some smc_conn_free() are not protected by sock lock. Calls under socklock | Calls not under socklock ------------------------------------------------------- lock_sock(sk) | smc_conn_abort smc_conn_free | \- smc_conn_free \- smcr_link_put | \- smcr_link_put (duplicated) release_sock(sk) So make sure smc_conn_free() is called under the sock lock. Fixes: 8cf3f3e42374 ("net/smc: use helper smc_conn_abort() in listen processing") Co-developed-by: Guangguan Wang Signed-off-by: Guangguan Wang Co-developed-by: Kai Signed-off-by: Kai Signed-off-by: Wen Gu --- net/smc/af_smc.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index ed6d4d520bc7..e0a7a0151b11 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -973,7 +973,8 @@ static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code, return smc_connect_fallback(smc, reason_code); } -static void smc_conn_abort(struct smc_sock *smc, int local_first) +static void __smc_conn_abort(struct smc_sock *smc, int local_first, + bool locked) { struct smc_connection *conn = &smc->conn; struct smc_link_group *lgr = conn->lgr; @@ -982,11 +983,27 @@ static void smc_conn_abort(struct smc_sock *smc, int local_first) if (smc_conn_lgr_valid(conn)) lgr_valid = true; - smc_conn_free(conn); + if (!locked) { + lock_sock(&smc->sk); + smc_conn_free(conn); + release_sock(&smc->sk); + } else { + smc_conn_free(conn); + } if (local_first && lgr_valid) smc_lgr_cleanup_early(lgr); } +static void smc_conn_abort(struct smc_sock *smc, int local_first) +{ + __smc_conn_abort(smc, local_first, false); +} + +static void smc_conn_abort_locked(struct smc_sock *smc, int local_first) +{ + __smc_conn_abort(smc, local_first, true); +} + /* check if there is a rdma device available for this connection. */ /* called for connect and listen */ static int smc_find_rdma_device(struct smc_sock *smc, struct smc_init_info *ini) @@ -1352,7 +1369,7 @@ static int smc_connect_rdma(struct smc_sock *smc, return 0; connect_abort: - smc_conn_abort(smc, ini->first_contact_local); + smc_conn_abort_locked(smc, ini->first_contact_local); mutex_unlock(&smc_client_lgr_pending); smc->connect_nonblock = 0; @@ -1454,7 +1471,7 @@ static int smc_connect_ism(struct smc_sock *smc, return 0; connect_abort: - smc_conn_abort(smc, ini->first_contact_local); + smc_conn_abort_locked(smc, ini->first_contact_local); mutex_unlock(&smc_server_lgr_pending); smc->connect_nonblock = 0;