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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3CEF6C433EF for ; Thu, 25 Nov 2021 03:20:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:MIME-Version:Date:Message-ID:References:To:From: Subject:Reply-To:Cc:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=rNXve4tMXrv35LXbcJk+UpP5girBnV8171M1iGJ8hj4=; b=Api94W9oT1RmnmPbhIappmhUGR ZbN/sFBjoOBrRgIHHHUkcAhgAMYT71K6XvuLcMWjehtDuDN1mCS9FsHdxu7FPTH505MkC1Baug7ME hwpzCJ3C5yrmvZSXEIifmKdQ4GsLBccmuk/LOK4KMoYDeXWMDcxxleh5schiDoHzm16Z/d+D3w4En dWbTrJqeAu+wFwRZY5bjUtdKysdFTUn2tB9d7vzNE9C1tWbVw46aRorYlKHJLhn2yqlrwAHQxNxDb jdqqMdzucJ1JD9uaaowXQqaygO00gigO+L4Pb6uIOfxFDQ5inme5ehBk766rz0WNVsINDF0mYPtFB hmVLehpQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mq5J7-006JkR-0D; Thu, 25 Nov 2021 03:20:21 +0000 Received: from szxga02-in.huawei.com ([45.249.212.188]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mq5J2-006Jj3-Et for linux-nvme@lists.infradead.org; Thu, 25 Nov 2021 03:20:18 +0000 Received: from dggemv704-chm.china.huawei.com (unknown [172.30.72.55]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4J03615DLlzbj3k for ; Thu, 25 Nov 2021 11:20:09 +0800 (CST) Received: from kwepemm600011.china.huawei.com (7.193.23.229) by dggemv704-chm.china.huawei.com (10.3.19.47) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Thu, 25 Nov 2021 11:20:12 +0800 Received: from [10.169.46.19] (10.169.46.19) by kwepemm600011.china.huawei.com (7.193.23.229) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Thu, 25 Nov 2021 11:20:11 +0800 Subject: Re: [PATCH 1/1] nvme: fix use after free when disconnect a reconnecting ctrl From: liruozhu To: , References: <20211104071332.28952-1-liruozhu@huawei.com> <20211104071332.28952-2-liruozhu@huawei.com> Message-ID: <932cec36-fe0b-7739-9551-7492ff656d46@huawei.com> Date: Thu, 25 Nov 2021 11:20:10 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.0.1 MIME-Version: 1.0 In-Reply-To: <20211104071332.28952-2-liruozhu@huawei.com> Content-Type: text/plain; charset="gbk"; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Originating-IP: [10.169.46.19] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemm600011.china.huawei.com (7.193.23.229) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211124_192016_734088_DF251EC1 X-CRM114-Status: GOOD ( 19.91 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org Ping... On 2021/11/4 15:13, Ruozhu Li wrote: > A crash happens when I try to disconnect a reconnecting ctrl: > > 1) The network was cut off when the connection was just established, > scan work hang there waiting for some IOs complete.Those IOs were > retrying because we return BLK_STS_RESOURCE to blk in reconnecting. > > 2) After a while, I tried to disconnect this connection.This procedure > also hung because it tried to obtain ctrl->scan_lock.It should be noted > that now we have switched the controller state to NVME_CTRL_DELETING. > > 3) In nvme_check_ready(), we always return true when ctrl->state is > NVME_CTRL_DELETING, so those retrying IOs were issued to the bottom > device which was already freed. > > To fix this, when ctrl->state is NVME_CTRL_DELETING, issue cmd to bottom > device only when queue state is live.If not, return host path error to blk. > > Signed-off-by: Ruozhu Li > --- > drivers/nvme/host/core.c | 1 + > drivers/nvme/host/nvme.h | 2 +- > 2 files changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c > index 838b5e2058be..752203ad7639 100644 > --- a/drivers/nvme/host/core.c > +++ b/drivers/nvme/host/core.c > @@ -666,6 +666,7 @@ blk_status_t nvme_fail_nonready_command(struct nvme_ctrl *ctrl, > struct request *rq) > { > if (ctrl->state != NVME_CTRL_DELETING_NOIO && > + ctrl->state != NVME_CTRL_DELETING && > ctrl->state != NVME_CTRL_DEAD && > !test_bit(NVME_CTRL_FAILFAST_EXPIRED, &ctrl->flags) && > !blk_noretry_request(rq) && !(rq->cmd_flags & REQ_NVME_MPATH)) > diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h > index b334af8aa264..9b095ee01364 100644 > --- a/drivers/nvme/host/nvme.h > +++ b/drivers/nvme/host/nvme.h > @@ -709,7 +709,7 @@ static inline bool nvme_check_ready(struct nvme_ctrl *ctrl, struct request *rq, > return true; > if (ctrl->ops->flags & NVME_F_FABRICS && > ctrl->state == NVME_CTRL_DELETING) > - return true; > + return queue_live; > return __nvme_check_ready(ctrl, rq, queue_live); > } > int nvme_submit_sync_cmd(struct request_queue *q, struct nvme_command *cmd,