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 7D577EC8756 for ; Fri, 8 Sep 2023 01:35:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234997AbjIHBfM (ORCPT ); Thu, 7 Sep 2023 21:35:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40316 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230521AbjIHBfL (ORCPT ); Thu, 7 Sep 2023 21:35:11 -0400 Received: from out-229.mta1.migadu.com (out-229.mta1.migadu.com [95.215.58.229]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 94C4B1BD9 for ; Thu, 7 Sep 2023 18:35:05 -0700 (PDT) Message-ID: <332d5cd8-c0ab-3657-513d-0d385fc4bdca@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1694136903; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=LP/y5xGfIbK4Rs5aCZwdj37gLU9jDNrII6xvBf338hU=; b=jM/p+Cbhhyt3mr1q04p/FPcA9UDDB2wwaC5gqdSxxWawnjGubnquUmFMvFTfVND0Jaz7af RNlKqHPmh1MeqmkJ9QEMrBfoPZin6yHbGpYl4PVfS1g8voSVAhhCXuEFDm9Ln1OsriSAhS e94EG4LSmuA7G9AGyWxqbOBvT/QygIo= Date: Fri, 8 Sep 2023 09:34:54 +0800 MIME-Version: 1.0 X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Guoqing Jiang Subject: Re: [PATCH v2] RDMA/siw: Fix connection failure handling To: Bernard Metzler , linux-rdma@vger.kernel.org Cc: jgg@ziepe.ca, leon@kernel.org References: <20230905145822.446263-1-bmt@zurich.ibm.com> Content-Language: en-US In-Reply-To: <20230905145822.446263-1-bmt@zurich.ibm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Hi, On 9/5/23 22:58, Bernard Metzler wrote: > In case immediate MPA request processing fails, the newly > created endpoint unlinks the listening endpoint and is > ready to be dropped. This special case was not handled > correctly by the code handling the later TCP socket close, > causing a NULL dereference crash in siw_cm_work_handler() > when dereferencing a NULL listener. We now also cancel > the useless MPA timeout, if immediate MPA request > processing fails. > > This patch furthermore simplifies MPA processing in general: > Scheduling a useless TCP socket read in sk_data_ready() upcall > is now surpressed, if the socket is already moved out of > TCP_ESTABLISHED state. > > Fixes: 6c52fdc244b5 ("rdma/siw: connection management") > Signed-off-by: Bernard Metzler > --- > ChangeLog v1->v2: > - Move debug message to now conditional listener drop > --- > drivers/infiniband/sw/siw/siw_cm.c | 16 ++++++++++++---- > 1 file changed, 12 insertions(+), 4 deletions(-) > > diff --git a/drivers/infiniband/sw/siw/siw_cm.c b/drivers/infiniband/sw/siw/siw_cm.c > index a2605178f4ed..43e776073f49 100644 > --- a/drivers/infiniband/sw/siw/siw_cm.c > +++ b/drivers/infiniband/sw/siw/siw_cm.c > @@ -976,6 +976,7 @@ static void siw_accept_newconn(struct siw_cep *cep) > siw_cep_put(cep); > new_cep->listen_cep = NULL; > if (rv) { > + siw_cancel_mpatimer(new_cep); One question, why siw_cm_work_handler set cep->mpa_timer to NULL instead of call siw_cancel_mpatimer like above? Could it be memory leak issue for cep->mpa_timer? Let's say mpa_timer is set to NULL before  call siw_cancel_mpatimer. > siw_cep_set_free(new_cep); > goto error; > } > @@ -1100,9 +1101,12 @@ static void siw_cm_work_handler(struct work_struct *w) > /* > * Socket close before MPA request received. > */ > - siw_dbg_cep(cep, "no mpareq: drop listener\n"); > - siw_cep_put(cep->listen_cep); > - cep->listen_cep = NULL; > + if (cep->listen_cep) { > + siw_dbg_cep(cep, > + "no mpareq: drop listener\n"); > + siw_cep_put(cep->listen_cep); > + cep->listen_cep = NULL; > + } > } > } > release_cep = 1; > @@ -1227,7 +1231,11 @@ static void siw_cm_llp_data_ready(struct sock *sk) > if (!cep) > goto out; > > - siw_dbg_cep(cep, "state: %d\n", cep->state); > + siw_dbg_cep(cep, "cep state: %d, socket state %d\n", > + cep->state, sk->sk_state); > + > + if (sk->sk_state != TCP_ESTABLISHED) > + goto out; > Maybe split above to another patch makes more sense, just my $0.02. Thanks, Guoqing