Commit ad40f525 authored by Chad Dupuis's avatar Chad Dupuis Committed by Martin K. Petersen
Browse files

scsi: qedf: Fix crash when MFW calls for protocol stats while function is still probing 

The MFW may make a call to qed and then to qedf for protocol statistics
while the function is still probing.  If this happens it's possible that
some members of the struct qedf_ctx may not be fully initialized which can
result in a NULL pointer dereference or general protection fault.

To prevent this, add a new flag call QEDF_PROBING and set it when the
__qedf_probe() function is active. Then in the qedf_get_protocol_tlv_data()
function we can check if the function is still probing and return
immediantely before any uninitialized structures can be touched.

Link: https://lore.kernel.org/r/20200416084314.18851-9-skashyap@marvell.com


Signed-off-by: default avatarChad Dupuis <cdupuis@marvell.com>
Signed-off-by: default avatarSaurav Kashyap <skashyap@marvell.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent f6b172f2

drivers/scsi/qedf/qedf.h

+1 −0
Original line number Diff line number Diff line
@@ -355,6 +355,7 @@ struct qedf_ctx { 
#define QEDF_GRCDUMP_CAPTURE		4

#define QEDF_IN_RECOVERY		5

#define QEDF_DBG_STOP_IO		6

#define QEDF_PROBING			8

	unsigned long flags; /* Miscellaneous state flags */

	int fipvlan_retries;

	u8 num_queues;

drivers/scsi/qedf/qedf_main.c

+31 −4
Original line number Diff line number Diff line
@@ -3190,7 +3190,7 @@ static int __qedf_probe(struct pci_dev *pdev, int mode) 
{

	int rc = -EINVAL;

	struct fc_lport *lport;

	struct qedf_ctx *qedf;

	struct qedf_ctx *qedf = NULL;

	struct Scsi_Host *host;

	bool is_vf = false;

	struct qed_ll2_params params;
@@ -3220,6 +3220,7 @@ static int __qedf_probe(struct pci_dev *pdev, int mode) 


		/* Initialize qedf_ctx */

		qedf = lport_priv(lport);

		set_bit(QEDF_PROBING, &qedf->flags);

		qedf->lport = lport;

		qedf->ctlr.lp = lport;

		qedf->pdev = pdev;
@@ -3244,9 +3245,12 @@ static int __qedf_probe(struct pci_dev *pdev, int mode) 
	} else {

		/* Init pointers during recovery */

		qedf = pci_get_drvdata(pdev);

		set_bit(QEDF_PROBING, &qedf->flags);

		lport = qedf->lport;

	}



	QEDF_INFO(&qedf->dbg_ctx, QEDF_LOG_DISC, "Probe started.\n");



	host = lport->host;



	/* Allocate mempool for qedf_io_work structs */
@@ -3553,6 +3557,10 @@ static int __qedf_probe(struct pci_dev *pdev, int mode) 
	else

		fc_fabric_login(lport);



	QEDF_INFO(&qedf->dbg_ctx, QEDF_LOG_DISC, "Probe done.\n");



	clear_bit(QEDF_PROBING, &qedf->flags);



	/* All good */

	return 0;
@@ -3578,6 +3586,11 @@ err2: 
err1:

	scsi_host_put(lport->host);

err0:

	if (qedf) {

		QEDF_INFO(&qedf->dbg_ctx, QEDF_LOG_DISC, "Probe done.\n");



		clear_bit(QEDF_PROBING, &qedf->flags);

	}

	return rc;

}
@@ -3727,11 +3740,25 @@ void qedf_get_protocol_tlv_data(void *dev, void *data) 
{

	struct qedf_ctx *qedf = dev;

	struct qed_mfw_tlv_fcoe *fcoe = data;

	struct fc_lport *lport = qedf->lport;

	struct Scsi_Host *host = lport->host;

	struct fc_host_attrs *fc_host = shost_to_fc_host(host);

	struct fc_lport *lport;

	struct Scsi_Host *host;

	struct fc_host_attrs *fc_host;

	struct fc_host_statistics *hst;



	if (!qedf) {

		QEDF_ERR(NULL, "qedf is null.\n");

		return;

	}



	if (test_bit(QEDF_PROBING, &qedf->flags)) {

		QEDF_ERR(&qedf->dbg_ctx, "Function is still probing.\n");

		return;

	}



	lport = qedf->lport;

	host = lport->host;

	fc_host = shost_to_fc_host(host);



	/* Force a refresh of the fc_host stats including offload stats */

	hst = qedf_fc_get_host_stats(host);

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