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=-11.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 E50EBC388F9 for ; Fri, 23 Oct 2020 08:45:43 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4C63024182 for ; Fri, 23 Oct 2020 08:45:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="odMcHmNb" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4C63024182 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=N0dLAGjjiseWE4+Zw99qeexkz1e+YQrRo2GjBAP69hc=; b=odMcHmNbk504YTQpWY8CLXE1w Zlb8oTK3qIn8CsSDbCGNuinRQsIZBXChNxE3iHeZ4dEpDyUOB3snmRHNw/gxsfT8G0MIvuQfo1bsx +xKxIRLNfC8o8x11z7AoW9142ZWxNNKC4EXFTuQZj6F//34WrsIQifsZi5y68R8tIx3rzX/lrJYdL azB2oLhiGUR5Wv46+7xdAvV/z/htrC6uogsV4OAFh/TO8vlVwPQ9dVx16z4/XfsDDrWXYAllwErnP piD8oqDNC+SdP6+l7VQa3DSXszNr5bh64sDt0X/jbkN0CcfqxQm5pHYWDPA/EMd6zzntflZeiTmTY 4GjwGamrQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kVshc-0003we-0V; Fri, 23 Oct 2020 08:45:36 +0000 Received: from szxga01-in.huawei.com ([45.249.212.187] helo=huawei.com) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kVshY-0003vY-8F for linux-nvme@lists.infradead.org; Fri, 23 Oct 2020 08:45:33 +0000 Received: from DGGEMM402-HUB.china.huawei.com (unknown [172.30.72.55]) by Forcepoint Email with ESMTP id 496BE74777AFF58E673F; Fri, 23 Oct 2020 16:45:25 +0800 (CST) Received: from dggema772-chm.china.huawei.com (10.1.198.214) by DGGEMM402-HUB.china.huawei.com (10.3.20.210) with Microsoft SMTP Server (TLS) id 14.3.487.0; Fri, 23 Oct 2020 16:45:24 +0800 Received: from [10.169.42.93] (10.169.42.93) by dggema772-chm.china.huawei.com (10.1.198.214) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1913.5; Fri, 23 Oct 2020 16:45:24 +0800 Subject: Re: [PATCH v2] nvme-rdma: handle nvme completion data length To: zhenwei pi , , , , References: <20201023065910.1358586-1-pizhenwei@bytedance.com> From: Chao Leng Message-ID: <33381bb5-6daa-5f47-9e3c-a57eeb490950@huawei.com> Date: Fri, 23 Oct 2020 16:45:23 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <20201023065910.1358586-1-pizhenwei@bytedance.com> Content-Language: en-US X-Originating-IP: [10.169.42.93] X-ClientProxiedBy: dggeme707-chm.china.huawei.com (10.1.199.103) To dggema772-chm.china.huawei.com (10.1.198.214) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201023_044532_597472_CA9CA9B3 X-CRM114-Status: GOOD ( 18.99 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org Looks good. Reviewed-by: Chao Leng On 2020/10/23 14:59, zhenwei pi wrote: > Hit a kernel warning: > refcount_t: underflow; use-after-free. > WARNING: CPU: 0 PID: 0 at lib/refcount.c:28 > > RIP: 0010:refcount_warn_saturate+0xd9/0xe0 > Call Trace: > > nvme_rdma_recv_done+0xf3/0x280 [nvme_rdma] > __ib_process_cq+0x76/0x150 [ib_core] > ... > > The reason is that a zero bytes message received from target, and the > host side continues to process without length checking, then the > previous CQE is processed twice. > > Handle data length, ignore zero bytes message, and try to recovery for > corrupted CQE case. > > Thanks to Chao Leng for suggestions. > > Signed-off-by: zhenwei pi > --- > drivers/nvme/host/rdma.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c > index 9e378d0a0c01..2ecadd309f4a 100644 > --- a/drivers/nvme/host/rdma.c > +++ b/drivers/nvme/host/rdma.c > @@ -1767,6 +1767,21 @@ static void nvme_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc) > return; > } > > + /* received data length checking */ > + if (unlikely(wc->byte_len < len)) { > + /* zero bytes message could be ignored */ > + if (!wc->byte_len) { > + nvme_rdma_post_recv(queue, qe); > + return; > + } > + > + /* corrupted completion, try to recovry */ > + dev_err(queue->ctrl->ctrl.device, > + "Unexpected nvme completion length(%d)\n", wc->byte_len); > + nvme_rdma_error_recovery(queue->ctrl); > + return; > + } > + > ib_dma_sync_single_for_cpu(ibdev, qe->dma, len, DMA_FROM_DEVICE); > /* > * AEN requests are special as they don't time out and can > _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme