scsi: fnic: Fix crash in fnic_wq_cmpl_handler when FDMI times out

When both the RHBA and RPA FDMI requests time out, fnic reuses a frame to
send ABTS for each of them. On send completion, this causes an attempt to
free the same frame twice that leads to a crash.

Fix crash by allocating separate frames for RHBA and RPA, and modify ABTS
logic accordingly.

Tested by checking MDS for FDMI information.

Tested by using instrumented driver to:

 - Drop PLOGI response
 - Drop RHBA response
 - Drop RPA response
 - Drop RHBA and RPA response
 - Drop PLOGI response + ABTS response
 - Drop RHBA response + ABTS response
 - Drop RPA response + ABTS response
 - Drop RHBA and RPA response + ABTS response for both of them

Fixes: 09c1e6a ("scsi: fnic: Add and integrate support for FDMI")
Reviewed-by: Sesidhar Baddela <[email protected]>
Reviewed-by: Arulprabhu Ponnusamy <[email protected]>
Reviewed-by: Gian Carlo Boffa <[email protected]>
Tested-by: Arun Easi <[email protected]>
Co-developed-by: Arun Easi <[email protected]>
Signed-off-by: Arun Easi <[email protected]>
Tested-by: Karan Tilak Kumar <[email protected]>
Cc: [email protected]
Signed-off-by: Karan Tilak Kumar <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: John Meneghini <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>

Author: Karan Tilak Kumar

drivers/scsi/fnic/fdls_disc.c

@@ -763,47 +763,69 @@ static void fdls_send_fabric_abts(struct fnic_iport_s *iport)
 	iport->fabric.timer_pending = 1;
 }
 
-static void fdls_send_fdmi_abts(struct fnic_iport_s *iport)
+static uint8_t *fdls_alloc_init_fdmi_abts_frame(struct fnic_iport_s *iport,
+		uint16_t oxid)
 {
-	uint8_t *frame;
+	struct fc_frame_header *pfdmi_abts;
 	uint8_t d_id[3];
+	uint8_t *frame;
 	struct fnic *fnic = iport->fnic;
-	struct fc_frame_header *pfabric_abts;
-	unsigned long fdmi_tov;
-	uint16_t oxid;
-	uint16_t frame_size = FNIC_ETH_FCOE_HDRS_OFFSET +
-			sizeof(struct fc_frame_header);
 
 	frame = fdls_alloc_frame(iport);
 	if (frame == NULL) {
 		FNIC_FCS_DBG(KERN_ERR, fnic->host, fnic->fnic_num,
 				"Failed to allocate frame to send FDMI ABTS");
-		return;
+		return NULL;
 	}
 
-	pfabric_abts = (struct fc_frame_header *) (frame + FNIC_ETH_FCOE_HDRS_OFFSET);
+	pfdmi_abts = (struct fc_frame_header *) (frame + FNIC_ETH_FCOE_HDRS_OFFSET);
 	fdls_init_fabric_abts_frame(frame, iport);
 
 	hton24(d_id, FC_FID_MGMT_SERV);
-	FNIC_STD_SET_D_ID(*pfabric_abts, d_id);
+	FNIC_STD_SET_D_ID(*pfdmi_abts, d_id);
+	FNIC_STD_SET_OX_ID(*pfdmi_abts, oxid);
+
+	return frame;
+}
+
+static void fdls_send_fdmi_abts(struct fnic_iport_s *iport)
+{
+	uint8_t *frame;
+	unsigned long fdmi_tov;
+	uint16_t frame_size = FNIC_ETH_FCOE_HDRS_OFFSET +
+			sizeof(struct fc_frame_header);
 
 	if (iport->fabric.fdmi_pending & FDLS_FDMI_PLOGI_PENDING) {
-		oxid = iport->active_oxid_fdmi_plogi;
-		FNIC_STD_SET_OX_ID(*pfabric_abts, oxid);
+		frame = fdls_alloc_init_fdmi_abts_frame(iport,
+						iport->active_oxid_fdmi_plogi);
+		if (frame == NULL)
+			return;
+
 		fnic_send_fcoe_frame(iport, frame, frame_size);
 	} else {
 		if (iport->fabric.fdmi_pending & FDLS_FDMI_REG_HBA_PENDING) {
-			oxid = iport->active_oxid_fdmi_rhba;
-			FNIC_STD_SET_OX_ID(*pfabric_abts, oxid);
+			frame = fdls_alloc_init_fdmi_abts_frame(iport,
+						iport->active_oxid_fdmi_rhba);
+			if (frame == NULL)
+				return;
+
 			fnic_send_fcoe_frame(iport, frame, frame_size);
 		}
 		if (iport->fabric.fdmi_pending & FDLS_FDMI_RPA_PENDING) {
-			oxid = iport->active_oxid_fdmi_rpa;
-			FNIC_STD_SET_OX_ID(*pfabric_abts, oxid);
+			frame = fdls_alloc_init_fdmi_abts_frame(iport,
+						iport->active_oxid_fdmi_rpa);
+			if (frame == NULL) {
+				if (iport->fabric.fdmi_pending & FDLS_FDMI_REG_HBA_PENDING)
+					goto arm_timer;
+				else
+					return;
+			}
+
 			fnic_send_fcoe_frame(iport, frame, frame_size);
 		}
 	}
 
+arm_timer:
 	fdmi_tov = jiffies + msecs_to_jiffies(2 * iport->e_d_tov);
 	mod_timer(&iport->fabric.fdmi_timer, round_jiffies(fdmi_tov));
 	iport->fabric.fdmi_pending |= FDLS_FDMI_ABORT_PENDING;
@@ -2245,6 +2267,21 @@ void fdls_fabric_timer_callback(struct timer_list *t)
 	spin_unlock_irqrestore(&fnic->fnic_lock, flags);
 }
 
+void fdls_fdmi_retry_plogi(struct fnic_iport_s *iport)
+{
+	struct fnic *fnic = iport->fnic;
+
+	iport->fabric.fdmi_pending = 0;
+	/* If max retries not exhausted, start over from fdmi plogi */
+	if (iport->fabric.fdmi_retry < FDLS_FDMI_MAX_RETRY) {
+		iport->fabric.fdmi_retry++;
+		FNIC_FCS_DBG(KERN_INFO, fnic->host, fnic->fnic_num,
+					 "Retry FDMI PLOGI. FDMI retry: %d",
+					 iport->fabric.fdmi_retry);
+		fdls_send_fdmi_plogi(iport);
+	}
+}
+
 void fdls_fdmi_timer_callback(struct timer_list *t)
 {
 	struct fnic_fdls_fabric_s *fabric = timer_container_of(fabric, t,
@@ -2291,14 +2328,7 @@ void fdls_fdmi_timer_callback(struct timer_list *t)
 	FNIC_FCS_DBG(KERN_INFO, fnic->host, fnic->fnic_num,
 		"fdmi timer callback : 0x%x\n", iport->fabric.fdmi_pending);
 
-	iport->fabric.fdmi_pending = 0;
-	/* If max retries not exhaused, start over from fdmi plogi */
-	if (iport->fabric.fdmi_retry < FDLS_FDMI_MAX_RETRY) {
-		iport->fabric.fdmi_retry++;
-		FNIC_FCS_DBG(KERN_INFO, fnic->host, fnic->fnic_num,
-					 "retry fdmi timer %d", iport->fabric.fdmi_retry);
-		fdls_send_fdmi_plogi(iport);
-	}
+	fdls_fdmi_retry_plogi(iport);
 	FNIC_FCS_DBG(KERN_INFO, fnic->host, fnic->fnic_num,
 		"fdmi timer callback : 0x%x\n", iport->fabric.fdmi_pending);
 	spin_unlock_irqrestore(&fnic->fnic_lock, flags);
@@ -3716,11 +3746,32 @@ static void fdls_process_fdmi_abts_rsp(struct fnic_iport_s *iport,
 	switch (FNIC_FRAME_TYPE(oxid)) {
 	case FNIC_FRAME_TYPE_FDMI_PLOGI:
 		fdls_free_oxid(iport, oxid, &iport->active_oxid_fdmi_plogi);
+
+		iport->fabric.fdmi_pending &= ~FDLS_FDMI_PLOGI_PENDING;
+		iport->fabric.fdmi_pending &= ~FDLS_FDMI_ABORT_PENDING;
 		break;
 	case FNIC_FRAME_TYPE_FDMI_RHBA:
+		iport->fabric.fdmi_pending &= ~FDLS_FDMI_REG_HBA_PENDING;
+
+		/* If RPA is still pending, don't turn off ABORT PENDING.
+		 * We count on the timer to detect the ABTS timeout and take
+		 * corrective action.
+		 */
+		if (!(iport->fabric.fdmi_pending & FDLS_FDMI_RPA_PENDING))
+			iport->fabric.fdmi_pending &= ~FDLS_FDMI_ABORT_PENDING;
+
 		fdls_free_oxid(iport, oxid, &iport->active_oxid_fdmi_rhba);
 		break;
 	case FNIC_FRAME_TYPE_FDMI_RPA:
+		iport->fabric.fdmi_pending &= ~FDLS_FDMI_RPA_PENDING;
+
+		/* If RHBA is still pending, don't turn off ABORT PENDING.
+		 * We count on the timer to detect the ABTS timeout and take
+		 * corrective action.
+		 */
+		if (!(iport->fabric.fdmi_pending & FDLS_FDMI_REG_HBA_PENDING))
+			iport->fabric.fdmi_pending &= ~FDLS_FDMI_ABORT_PENDING;
+
 		fdls_free_oxid(iport, oxid, &iport->active_oxid_fdmi_rpa);
 		break;
 	default:
@@ -3730,10 +3781,16 @@ static void fdls_process_fdmi_abts_rsp(struct fnic_iport_s *iport,
 		break;
 	}
 
-	timer_delete_sync(&iport->fabric.fdmi_timer);
-	iport->fabric.fdmi_pending &= ~FDLS_FDMI_ABORT_PENDING;
-
-	fdls_send_fdmi_plogi(iport);
+	/*
+	 * Only if ABORT PENDING is off, delete the timer, and if no other
+	 * operations are pending, retry FDMI.
+	 * Otherwise, let the timer pop and take the appropriate action.
+	 */
+	if (!(iport->fabric.fdmi_pending & FDLS_FDMI_ABORT_PENDING)) {
+		timer_delete_sync(&iport->fabric.fdmi_timer);
+		if (!iport->fabric.fdmi_pending)
+			fdls_fdmi_retry_plogi(iport);
+	}
 }
 
 static void

drivers/scsi/fnic/fnic.h

@@ -30,7 +30,7 @@
 
 #define DRV_NAME		"fnic"
 #define DRV_DESCRIPTION		"Cisco FCoE HBA Driver"
-#define DRV_VERSION		"1.8.0.0"
+#define DRV_VERSION		"1.8.0.1"
 #define PFX			DRV_NAME ": "
 #define DFX                     DRV_NAME "%d: "
 

drivers/scsi/fnic/fnic_fdls.h

@@ -394,6 +394,7 @@ void fdls_send_tport_abts(struct fnic_iport_s *iport,
 bool fdls_delete_tport(struct fnic_iport_s *iport,
 		       struct fnic_tport_s *tport);
 void fdls_fdmi_timer_callback(struct timer_list *t);
+void fdls_fdmi_retry_plogi(struct fnic_iport_s *iport);
 
 /* fnic_fcs.c */
 void fnic_fdls_init(struct fnic *fnic, int usefip);