ata,scsi: libata-core: Do not leak memory for ata_port struct members

libsas is currently not freeing all the struct ata_port struct members,
e.g. ncq_sense_buf for a driver supporting Command Duration Limits (CDL).

Add a function, ata_port_free(), that is used to free a ata_port,
including its struct members. It makes sense to keep the code related to
freeing a ata_port in its own function, which will also free all the
struct members of struct ata_port.

Fixes: 18bd771 ("scsi: ata: libata: Handle completion of CDL commands using policy 0xD")
Reviewed-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20240629124210.181537-8-cassel@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>

drivers/ata/libata-core.c

@@ -5489,6 +5489,18 @@ struct ata_port *ata_port_alloc(struct ata_host *host)
 	return ap;
 }
 
+void ata_port_free(struct ata_port *ap)
+{
+	if (!ap)
+		return;
+
+	kfree(ap->pmp_link);
+	kfree(ap->slave_link);
+	kfree(ap->ncq_sense_buf);
+	kfree(ap);
+}
+EXPORT_SYMBOL_GPL(ata_port_free);
+
 static void ata_devres_release(struct device *gendev, void *res)
 {
 	struct ata_host *host = dev_get_drvdata(gendev);
@@ -5515,15 +5527,7 @@ static void ata_host_release(struct kref *kref)
 	int i;
 
 	for (i = 0; i < host->n_ports; i++) {
-		struct ata_port *ap = host->ports[i];
-
-		if (!ap)
-			continue;
-
-		kfree(ap->pmp_link);
-		kfree(ap->slave_link);
-		kfree(ap->ncq_sense_buf);
-		kfree(ap);
+		ata_port_free(host->ports[i]);
 		host->ports[i] = NULL;
 	}
 	kfree(host);
@@ -5906,7 +5910,7 @@ int ata_host_register(struct ata_host *host, const struct scsi_host_template *sh
 	 * allocation time.
 	 */
 	for (i = host->n_ports; host->ports[i]; i++)
-		kfree(host->ports[i]);
+		ata_port_free(host->ports[i]);
 
 	/* give ports names and add SCSI hosts */
 	for (i = 0; i < host->n_ports; i++) {

drivers/scsi/libsas/sas_ata.c

@@ -610,15 +610,15 @@ int sas_ata_init(struct domain_device *found_dev)
 
 	rc = ata_sas_tport_add(ata_host->dev, ap);
 	if (rc)
-		goto destroy_port;
+		goto free_port;
 
 	found_dev->sata_dev.ata_host = ata_host;
 	found_dev->sata_dev.ap = ap;
 
 	return 0;
 
-destroy_port:
-	kfree(ap);
+free_port:
+	ata_port_free(ap);
 free_host:
 	ata_host_put(ata_host);
 	return rc;

drivers/scsi/libsas/sas_discover.c

@@ -301,7 +301,7 @@ void sas_free_device(struct kref *kref)
 
 	if (dev_is_sata(dev) && dev->sata_dev.ap) {
 		ata_sas_tport_delete(dev->sata_dev.ap);
-		kfree(dev->sata_dev.ap);
+		ata_port_free(dev->sata_dev.ap);
 		ata_host_put(dev->sata_dev.ata_host);
 		dev->sata_dev.ata_host = NULL;
 		dev->sata_dev.ap = NULL;

include/linux/libata.h

@@ -1249,6 +1249,7 @@ extern int ata_slave_link_init(struct ata_port *ap);
 extern struct ata_port *ata_sas_port_alloc(struct ata_host *,
 					   struct ata_port_info *, struct Scsi_Host *);
 extern void ata_port_probe(struct ata_port *ap);
+extern void ata_port_free(struct ata_port *ap);
 extern int ata_sas_tport_add(struct device *parent, struct ata_port *ap);
 extern void ata_sas_tport_delete(struct ata_port *ap);
 int ata_sas_device_configure(struct scsi_device *sdev, struct queue_limits *lim,