[PATCH AUTOSEL 4.9 16/26] PCI: Fix pci_create_slot() reference count leak

[Sasha Levin]

From: Qiushi Wu <wu000273@xxxxxxx>

[ Upstream commit 8a94644b440eef5a7b9c104ac8aa7a7f413e35e5 ]

kobject_init_and_add() takes a reference even when it fails.  If it returns
an error, kobject_put() must be called to clean up the memory associated
with the object.

When kobject_init_and_add() fails, call kobject_put() instead of kfree().

b8eb718348b8 ("net-sysfs: Fix reference count leak in
rx|netdev_queue_add_kobject") fixed a similar problem.

Link: https://lore.kernel.org/r/20200528021322.1984-1-wu000273@xxxxxxx
Signed-off-by: Qiushi Wu <wu000273@xxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/pci/slot.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/slot.c b/drivers/pci/slot.c
index 429d34c348b9f..01a343ad7155c 100644
--- a/drivers/pci/slot.c
+++ b/drivers/pci/slot.c
@@ -303,13 +303,16 @@ struct pci_slot *pci_create_slot(struct pci_bus *parent, int slot_nr,
 	slot_name = make_slot_name(name);
 	if (!slot_name) {
 		err = -ENOMEM;
+		kfree(slot);
 		goto err;
 	}
 
 	err = kobject_init_and_add(&slot->kobj, &pci_slot_ktype, NULL,
 				   "%s", slot_name);
-	if (err)
+	if (err) {
+		kobject_put(&slot->kobj);
 		goto err;
+	}
 
 	INIT_LIST_HEAD(&slot->list);
 	list_add(&slot->list, &parent->slots);
@@ -328,7 +331,6 @@ struct pci_slot *pci_create_slot(struct pci_bus *parent, int slot_nr,
 	mutex_unlock(&pci_slot_mutex);
 	return slot;
 err:
-	kfree(slot);
 	slot = ERR_PTR(err);
 	goto out;
 }
-- 
2.25.1