From 741f33d07b43d9585bec668d21d2cbbafdf646db Mon Sep 17 00:00:00 2001

From: Himanshu Madhani <hmadhani@redhat.com>

Date: Thu, 1 Aug 2019 15:56:02 -0400

Subject: [PATCH 102/124] [scsi] scsi: qla2xxx: Fix kernel crash after

 disconnecting NVMe devices

Message-id: <20190801155618.12650-103-hmadhani@redhat.com>

Patchwork-id: 267891

O-Subject: [RHEL 7.8 e-stor PATCH 102/118] scsi: qla2xxx: Fix kernel crash after disconnecting NVMe devices

Bugzilla: 1729270

RH-Acked-by: Jarod Wilson <jarod@redhat.com>

RH-Acked-by: Tony Camuso <tcamuso@redhat.com>

From: Arun Easi <aeasi@marvell.com>

Bugzilla 1729270

BUG: unable to handle kernel NULL pointer dereference at           (null)

IP: [<ffffffffc050d10c>] qla_nvme_unregister_remote_port+0x6c/0xf0 [qla2xxx]

PGD 800000084cf41067 PUD 84d288067 PMD 0

Oops: 0000 [#1] SMP

Call Trace:

 [<ffffffff98abcfdf>] process_one_work+0x17f/0x440

 [<ffffffff98abdca6>] worker_thread+0x126/0x3c0

 [<ffffffff98abdb80>] ? manage_workers.isra.26+0x2a0/0x2a0

 [<ffffffff98ac4f81>] kthread+0xd1/0xe0

 [<ffffffff98ac4eb0>] ? insert_kthread_work+0x40/0x40

 [<ffffffff9918ad37>] ret_from_fork_nospec_begin+0x21/0x21

 [<ffffffff98ac4eb0>] ? insert_kthread_work+0x40/0x40

RIP  [<ffffffffc050d10c>] qla_nvme_unregister_remote_port+0x6c/0xf0 [qla2xxx]

The crash is due to a bad entry in the nvme_rport_list. This list is not

protected, and when a remoteport_delete callback is called, driver

traverses the list and crashes.

Actually, the list could be removed and driver could traverse the main

fcport list instead. Fix does exactly that.

Signed-off-by: Arun Easi <aeasi@marvell.com>

Signed-off-by: Himanshu Madhani <hmadhani@redhat.com>

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

(cherry picked from commit 6a81533d616fe581b0d421ee6db3319eeac9486d)

Signed-off-by: Himanshu Madhani <hmadhani@redhat.com>

Signed-off-by: Jan Stancek <jstancek@redhat.com>

---

 drivers/scsi/qla2xxx/qla_def.h  |  1 -

 drivers/scsi/qla2xxx/qla_nvme.c | 37 ++++++++++---------------------------

 drivers/scsi/qla2xxx/qla_nvme.h |  1 -

 drivers/scsi/qla2xxx/qla_os.c   |  1 -

 4 files changed, 10 insertions(+), 30 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h

index e5e1081501a9..7d07c6e65eed 100644

--- a/drivers/scsi/qla2xxx/qla_def.h

+++ b/drivers/scsi/qla2xxx/qla_def.h

@@ -4411,7 +4411,6 @@ typedef struct scsi_qla_host {

 	struct		nvme_fc_local_port *nvme_local_port;

 	struct completion nvme_del_done;

-	struct list_head nvme_rport_list;

 	uint16_t	fcoe_vlan_id;

 	uint16_t	fcoe_fcf_idx;

diff --git a/drivers/scsi/qla2xxx/qla_nvme.c b/drivers/scsi/qla2xxx/qla_nvme.c

index dea081c27182..494082a6f8ed 100644

--- a/drivers/scsi/qla2xxx/qla_nvme.c

+++ b/drivers/scsi/qla2xxx/qla_nvme.c

@@ -74,7 +74,6 @@ int qla_nvme_register_remote(struct scsi_qla_host *vha, struct fc_port *fcport)

 	rport = fcport->nvme_remote_port->private;

 	rport->fcport = fcport;

-	list_add_tail(&rport->list, &vha->nvme_rport_list);

 	fcport->nvme_flag |= NVME_FLAG_REGISTERED;

 	return 0;

@@ -559,19 +558,12 @@ static void qla_nvme_localport_delete(struct nvme_fc_local_port *lport)

 static void qla_nvme_remoteport_delete(struct nvme_fc_remote_port *rport)

 {

 	fc_port_t *fcport;

-	struct qla_nvme_rport *qla_rport = rport->private, *trport;

+	struct qla_nvme_rport *qla_rport = rport->private;

 	fcport = qla_rport->fcport;

 	fcport->nvme_remote_port = NULL;

 	fcport->nvme_flag &= ~NVME_FLAG_REGISTERED;

-	list_for_each_entry_safe(qla_rport, trport,

-	    &fcport->vha->nvme_rport_list, list) {

-		if (qla_rport->fcport == fcport) {

-			list_del(&qla_rport->list);

-			break;

-		}

-	}

 	complete(&fcport->nvme_del_done);

 	if (!test_bit(UNLOADING, &fcport->vha->dpc_flags)) {

@@ -608,7 +600,7 @@ static void qla_nvme_unregister_remote_port(struct work_struct *work)

 {

 	struct fc_port *fcport = container_of(work, struct fc_port,

 	    nvme_del_work);

-	struct qla_nvme_rport *qla_rport, *trport;

+	int ret;

 	if (!IS_ENABLED(CONFIG_NVME_FC))

 		return;

@@ -616,23 +608,14 @@ static void qla_nvme_unregister_remote_port(struct work_struct *work)

 	ql_log(ql_log_warn, NULL, 0x2112,

 	    "%s: unregister remoteport on %p\n",__func__, fcport);

-	list_for_each_entry_safe(qla_rport, trport,

-	    &fcport->vha->nvme_rport_list, list) {

-		if (qla_rport->fcport == fcport) {

-			ql_log(ql_log_info, fcport->vha, 0x2113,

-			    "%s: fcport=%p\n", __func__, fcport);

-			nvme_fc_set_remoteport_devloss

-				(fcport->nvme_remote_port, 0);

-			init_completion(&fcport->nvme_del_done);

-			if (nvme_fc_unregister_remoteport

-			    (fcport->nvme_remote_port))

-				ql_log(ql_log_info, fcport->vha, 0x2114,

-				    "%s: Failed to unregister nvme_remote_port\n",

-				    __func__);

-			wait_for_completion(&fcport->nvme_del_done);

-			break;

-		}

-	}

+	nvme_fc_set_remoteport_devloss(fcport->nvme_remote_port, 0);

+	init_completion(&fcport->nvme_del_done);

+	ret = nvme_fc_unregister_remoteport(fcport->nvme_remote_port);

+	if (ret)

+		ql_log(ql_log_info, fcport->vha, 0x2114,

+			"%s: Failed to unregister nvme_remote_port (%d)\n",

+			    __func__, ret);

+	wait_for_completion(&fcport->nvme_del_done);

 }

 void qla_nvme_delete(struct scsi_qla_host *vha)

diff --git a/drivers/scsi/qla2xxx/qla_nvme.h b/drivers/scsi/qla2xxx/qla_nvme.h

index 0db04f0a4d5d..a48f9e7a3567 100644

--- a/drivers/scsi/qla2xxx/qla_nvme.h

+++ b/drivers/scsi/qla2xxx/qla_nvme.h

@@ -36,7 +36,6 @@ struct nvme_private {

 };

 struct qla_nvme_rport {

-	struct list_head list;

 	struct fc_port *fcport;

 };

diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c

index f3200e25d1e7..5009c5e4b276 100644

--- a/drivers/scsi/qla2xxx/qla_os.c

+++ b/drivers/scsi/qla2xxx/qla_os.c

@@ -4925,7 +4925,6 @@ struct scsi_qla_host *qla2x00_create_host(struct scsi_host_template *sht,

 	INIT_LIST_HEAD(&vha->logo_list);

 	INIT_LIST_HEAD(&vha->plogi_ack_list);

 	INIT_LIST_HEAD(&vha->gnl.fcports);

-	INIT_LIST_HEAD(&vha->nvme_rport_list);

 	INIT_LIST_HEAD(&vha->gpnid_list);

 	INIT_WORK(&vha->iocb_work, qla2x00_iocb_work_fn);

-- 

2.13.6