[PATCH] scsi: libsas: Handle errors in sas_ex_discover_expander()

The function sas_ex_discover_expander() does not account for the
potential failure of sas_port_alloc() for phy->port. It also calls
BUG_ON in case sas_port_add fails for phy->port. Add a check for
phy->port after sas_port_alloc() where if it is NULL, it cleans up the
child allocated device and returns NULL. Add another check for
sas_port_add() where if it returns an error code it frees phy->port,
sets it to NULL, cleans up the child allocated device, and returns NULL.

Signed-off-by: Eshaan Deshmukh <[email protected]>
---
 drivers/scsi/libsas/sas_expander.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index 1aa99e7c7..f9ae655a2 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -925,9 +925,18 @@ static struct domain_device *sas_ex_discover_expander(
 		return NULL;
 
 	phy->port = sas_port_alloc(&parent->rphy->dev, phy_id);
-	/* FIXME: better error handling */
-	BUG_ON(sas_port_add(phy->port) != 0);
+	if (!phy->port) {
+		sas_put_device(child);
+		return NULL;
+	}
 
+	res = sas_port_add(phy->port);
+	if (res) {
+		sas_port_free(phy->port);
+		phy->port = NULL;
+		sas_put_device(child);
+		return NULL;
+	}
 
 	switch (phy->attached_dev_type) {
 	case SAS_EDGE_EXPANDER_DEVICE:
-- 
2.55.0