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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 2E0E6C352B6 for ; Sat, 11 Apr 2020 23:08:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 08D0F21744 for ; Sat, 11 Apr 2020 23:08:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586646535; bh=mfsdc27c9Is7lCM07MtzICt/uZCLGi1YiEvmZs5Pmx0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=KEoeuc7MQ8lDgmBS0wO397hStxHrUp1knW4Vi+ZanT+KZSVplDkIF4W4ckwr0p1bw 5qHAsn9rn35zzM/BszoIZKcdAiPHpi0qRFJAjVyjtzxR2p7EvvMl5qJpFBS9W7Y1kv 5FhOgoYbuHfBcLmrz2NpqtYCJ6UTYHwx9hlwpA44= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729022AbgDKXIw (ORCPT ); Sat, 11 Apr 2020 19:08:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:46016 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729006AbgDKXIr (ORCPT ); Sat, 11 Apr 2020 19:08:47 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 70B0E216FD; Sat, 11 Apr 2020 23:08:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586646527; bh=mfsdc27c9Is7lCM07MtzICt/uZCLGi1YiEvmZs5Pmx0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IyGBOAzYqqZKhyCS92fRj+E7m0cV66QnbtB5rpr6Umn/yGEYP+9eVp3F7dPH5CHZT Fdi5KkcKwRYieuvnFDTldkLvJ/fmCcA69YuS6Wm/MOFSZwD5UFmx3ea1fn5N8pscXU QHVolO77i5viWNVq8E7LUtcaYR2gdk/3HY45ZolE= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jason Gunthorpe , Leon Romanovsky , Sasha Levin , linux-rdma@vger.kernel.org Subject: [PATCH AUTOSEL 5.5 082/121] RDMA/cm: Remove a race freeing timewait_info Date: Sat, 11 Apr 2020 19:06:27 -0400 Message-Id: <20200411230706.23855-82-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200411230706.23855-1-sashal@kernel.org> References: <20200411230706.23855-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jason Gunthorpe [ Upstream commit bede86a39d9dc3387ac00dcb8e1ac221676b2f25 ] When creating a cm_id during REQ the id immediately becomes visible to the other MAD handlers, and shortly after the state is moved to IB_CM_REQ_RCVD This allows cm_rej_handler() to run concurrently and free the work: CPU 0 CPU1 cm_req_handler() ib_create_cm_id() cm_match_req() id_priv->state = IB_CM_REQ_RCVD cm_rej_handler() cm_acquire_id() spin_lock(&id_priv->lock) switch (id_priv->state) case IB_CM_REQ_RCVD: cm_reset_to_idle() kfree(id_priv->timewait_info); goto destroy destroy: kfree(id_priv->timewait_info); id_priv->timewait_info = NULL Causing a double free or worse. Do not free the timewait_info without also holding the id_priv->lock. Simplify this entire flow by making the free unconditional during cm_destroy_id() and removing the confusing special case error unwind during creation of the timewait_info. This also fixes a leak of the timewait if cm_destroy_id() is called in IB_CM_ESTABLISHED with an XRC TGT QP. The state machine will be left in ESTABLISHED while it needed to transition through IB_CM_TIMEWAIT to release the timewait pointer. Also fix a leak of the timewait_info if the caller mis-uses the API and does ib_send_cm_reqs(). Fixes: a977049dacde ("[PATCH] IB: Add the kernel CM implementation") Link: https://lore.kernel.org/r/20200310092545.251365-4-leon@kernel.org Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin --- drivers/infiniband/core/cm.c | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-) diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c index f7afa1c75746b..4b00c6c83512d 100644 --- a/drivers/infiniband/core/cm.c +++ b/drivers/infiniband/core/cm.c @@ -1066,14 +1066,22 @@ static void cm_destroy_id(struct ib_cm_id *cm_id, int err) break; } - spin_lock_irq(&cm.lock); + spin_lock_irq(&cm_id_priv->lock); + spin_lock(&cm.lock); + /* Required for cleanup paths related cm_req_handler() */ + if (cm_id_priv->timewait_info) { + cm_cleanup_timewait(cm_id_priv->timewait_info); + kfree(cm_id_priv->timewait_info); + cm_id_priv->timewait_info = NULL; + } if (!list_empty(&cm_id_priv->altr_list) && (!cm_id_priv->altr_send_port_not_ready)) list_del(&cm_id_priv->altr_list); if (!list_empty(&cm_id_priv->prim_list) && (!cm_id_priv->prim_send_port_not_ready)) list_del(&cm_id_priv->prim_list); - spin_unlock_irq(&cm.lock); + spin_unlock(&cm.lock); + spin_unlock_irq(&cm_id_priv->lock); cm_free_id(cm_id->local_id); cm_deref_id(cm_id_priv); @@ -1390,7 +1398,7 @@ int ib_send_cm_req(struct ib_cm_id *cm_id, /* Verify that we're not in timewait. */ cm_id_priv = container_of(cm_id, struct cm_id_private, id); spin_lock_irqsave(&cm_id_priv->lock, flags); - if (cm_id->state != IB_CM_IDLE) { + if (cm_id->state != IB_CM_IDLE || WARN_ON(cm_id_priv->timewait_info)) { spin_unlock_irqrestore(&cm_id_priv->lock, flags); ret = -EINVAL; goto out; @@ -1408,12 +1416,12 @@ int ib_send_cm_req(struct ib_cm_id *cm_id, param->ppath_sgid_attr, &cm_id_priv->av, cm_id_priv); if (ret) - goto error1; + goto out; if (param->alternate_path) { ret = cm_init_av_by_path(param->alternate_path, NULL, &cm_id_priv->alt_av, cm_id_priv); if (ret) - goto error1; + goto out; } cm_id->service_id = param->service_id; cm_id->service_mask = ~cpu_to_be64(0); @@ -1431,7 +1439,7 @@ int ib_send_cm_req(struct ib_cm_id *cm_id, ret = cm_alloc_msg(cm_id_priv, &cm_id_priv->msg); if (ret) - goto error1; + goto out; req_msg = (struct cm_req_msg *) cm_id_priv->msg->mad; cm_format_req(req_msg, cm_id_priv, param); @@ -1454,7 +1462,6 @@ int ib_send_cm_req(struct ib_cm_id *cm_id, return 0; error2: cm_free_msg(cm_id_priv->msg); -error1: kfree(cm_id_priv->timewait_info); out: return ret; } EXPORT_SYMBOL(ib_send_cm_req); @@ -1935,7 +1942,7 @@ static int cm_req_handler(struct cm_work *work) pr_debug("%s: local_id %d, no listen_cm_id_priv\n", __func__, be32_to_cpu(cm_id->local_id)); ret = -EINVAL; - goto free_timeinfo; + goto destroy; } cm_id_priv->id.cm_handler = listen_cm_id_priv->id.cm_handler; @@ -2020,8 +2027,6 @@ static int cm_req_handler(struct cm_work *work) rejected: refcount_dec(&cm_id_priv->refcount); cm_deref_id(listen_cm_id_priv); -free_timeinfo: - kfree(cm_id_priv->timewait_info); destroy: ib_destroy_cm_id(cm_id); return ret; -- 2.20.1