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=-16.1 required=3.0 tests=BAYES_00,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 5C150C43465 for ; Fri, 18 Sep 2020 02:51:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1F07D23770 for ; Fri, 18 Sep 2020 02:51:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600397504; bh=IxCA4cikSGbdMv1b/t6Gfd0J3dPHUmZkz+mdtdpQs6M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=VTZ3a3dXC/Cf936C5T+bjaWvsiBbY7BeUIPC1OWxgIfQ9JnDdi2v3VWbFOAxVuZIf vHTxVbcVaXU0qFTVJw7wWOzkZL5avs04B+xdw4T6F6p5GIlfoBAtfYunk8GDw59Sh0 8PuXTl5lazgTKJmemUeD25t3aUvgnV4dJAYfqWK8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727495AbgIRCvn (ORCPT ); Thu, 17 Sep 2020 22:51:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:59636 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728082AbgIRCIX (ORCPT ); Thu, 17 Sep 2020 22:08:23 -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 CC74B2388E; Fri, 18 Sep 2020 02:08:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600394902; bh=IxCA4cikSGbdMv1b/t6Gfd0J3dPHUmZkz+mdtdpQs6M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Yb+cIqMy+o8Zt29UmQwA5JfIt9SEmLN6HGgmDmeEAT9QAIvgIJTd0h5EoTEZ7nEjB Wjsz78vhSYJV8zPaP3eDqM7AUxb8J+xmTRiKooqJgi6xwIvnK5l6aq48e5kBcaZPWS Wtf68J5Y+/vfHGoxINFJnlNVScufjxydFzFaIIGI= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: James Smart , Dick Kennedy , "Martin K . Petersen" , Sasha Levin , linux-scsi@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 016/206] scsi: lpfc: Fix kernel crash at lpfc_nvme_info_show during remote port bounce Date: Thu, 17 Sep 2020 22:04:52 -0400 Message-Id: <20200918020802.2065198-16-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200918020802.2065198-1-sashal@kernel.org> References: <20200918020802.2065198-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org From: James Smart [ Upstream commit 6c1e803eac846f886cd35131e6516fc51a8414b9 ] When reading sysfs nvme_info file while a remote port leaves and comes back, a NULL pointer is encountered. The issue is due to ndlp list corruption as the the nvme_info_show does not use the same lock as the rest of the code. Correct by removing the rcu_xxx_lock calls and replace by the host_lock and phba->hbaLock spinlocks that are used by the rest of the driver. Given we're called from sysfs, we are safe to use _irq rather than _irqsave. Link: https://lore.kernel.org/r/20191105005708.7399-4-jsmart2021@gmail.com Signed-off-by: Dick Kennedy Signed-off-by: James Smart Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/scsi/lpfc/lpfc_attr.c | 35 ++++++++++++++++++----------------- 1 file changed, 18 insertions(+), 17 deletions(-) diff --git a/drivers/scsi/lpfc/lpfc_attr.c b/drivers/scsi/lpfc/lpfc_attr.c index fe084d47ed9e5..3447d19d4147a 100644 --- a/drivers/scsi/lpfc/lpfc_attr.c +++ b/drivers/scsi/lpfc/lpfc_attr.c @@ -332,7 +332,6 @@ lpfc_nvme_info_show(struct device *dev, struct device_attribute *attr, if (strlcat(buf, "\nNVME Initiator Enabled\n", PAGE_SIZE) >= PAGE_SIZE) goto buffer_done; - rcu_read_lock(); scnprintf(tmp, sizeof(tmp), "XRI Dist lpfc%d Total %d NVME %d SCSI %d ELS %d\n", phba->brd_no, @@ -341,7 +340,7 @@ lpfc_nvme_info_show(struct device *dev, struct device_attribute *attr, phba->sli4_hba.scsi_xri_max, lpfc_sli4_get_els_iocb_cnt(phba)); if (strlcat(buf, tmp, PAGE_SIZE) >= PAGE_SIZE) - goto rcu_unlock_buf_done; + goto buffer_done; /* Port state is only one of two values for now. */ if (localport->port_id) @@ -357,7 +356,9 @@ lpfc_nvme_info_show(struct device *dev, struct device_attribute *attr, wwn_to_u64(vport->fc_nodename.u.wwn), localport->port_id, statep); if (strlcat(buf, tmp, PAGE_SIZE) >= PAGE_SIZE) - goto rcu_unlock_buf_done; + goto buffer_done; + + spin_lock_irq(shost->host_lock); list_for_each_entry(ndlp, &vport->fc_nodes, nlp_listp) { nrport = NULL; @@ -384,39 +385,39 @@ lpfc_nvme_info_show(struct device *dev, struct device_attribute *attr, /* Tab in to show lport ownership. */ if (strlcat(buf, "NVME RPORT ", PAGE_SIZE) >= PAGE_SIZE) - goto rcu_unlock_buf_done; + goto unlock_buf_done; if (phba->brd_no >= 10) { if (strlcat(buf, " ", PAGE_SIZE) >= PAGE_SIZE) - goto rcu_unlock_buf_done; + goto unlock_buf_done; } scnprintf(tmp, sizeof(tmp), "WWPN x%llx ", nrport->port_name); if (strlcat(buf, tmp, PAGE_SIZE) >= PAGE_SIZE) - goto rcu_unlock_buf_done; + goto unlock_buf_done; scnprintf(tmp, sizeof(tmp), "WWNN x%llx ", nrport->node_name); if (strlcat(buf, tmp, PAGE_SIZE) >= PAGE_SIZE) - goto rcu_unlock_buf_done; + goto unlock_buf_done; scnprintf(tmp, sizeof(tmp), "DID x%06x ", nrport->port_id); if (strlcat(buf, tmp, PAGE_SIZE) >= PAGE_SIZE) - goto rcu_unlock_buf_done; + goto unlock_buf_done; /* An NVME rport can have multiple roles. */ if (nrport->port_role & FC_PORT_ROLE_NVME_INITIATOR) { if (strlcat(buf, "INITIATOR ", PAGE_SIZE) >= PAGE_SIZE) - goto rcu_unlock_buf_done; + goto unlock_buf_done; } if (nrport->port_role & FC_PORT_ROLE_NVME_TARGET) { if (strlcat(buf, "TARGET ", PAGE_SIZE) >= PAGE_SIZE) - goto rcu_unlock_buf_done; + goto unlock_buf_done; } if (nrport->port_role & FC_PORT_ROLE_NVME_DISCOVERY) { if (strlcat(buf, "DISCSRVC ", PAGE_SIZE) >= PAGE_SIZE) - goto rcu_unlock_buf_done; + goto unlock_buf_done; } if (nrport->port_role & ~(FC_PORT_ROLE_NVME_INITIATOR | FC_PORT_ROLE_NVME_TARGET | @@ -424,14 +425,14 @@ lpfc_nvme_info_show(struct device *dev, struct device_attribute *attr, scnprintf(tmp, sizeof(tmp), "UNKNOWN ROLE x%x", nrport->port_role); if (strlcat(buf, tmp, PAGE_SIZE) >= PAGE_SIZE) - goto rcu_unlock_buf_done; + goto unlock_buf_done; } scnprintf(tmp, sizeof(tmp), "%s\n", statep); if (strlcat(buf, tmp, PAGE_SIZE) >= PAGE_SIZE) - goto rcu_unlock_buf_done; + goto unlock_buf_done; } - rcu_read_unlock(); + spin_unlock_irq(shost->host_lock); if (!lport) goto buffer_done; @@ -491,11 +492,11 @@ lpfc_nvme_info_show(struct device *dev, struct device_attribute *attr, atomic_read(&lport->cmpl_fcp_err)); strlcat(buf, tmp, PAGE_SIZE); - /* RCU is already unlocked. */ + /* host_lock is already unlocked. */ goto buffer_done; - rcu_unlock_buf_done: - rcu_read_unlock(); + unlock_buf_done: + spin_unlock_irq(shost->host_lock); buffer_done: len = strnlen(buf, PAGE_SIZE); -- 2.25.1