[PATCH 4.14 24/91] PCI: Fix pci_create_slot() reference count leak

Greg Kroah-Hartman
2020-09-01T15:20:29Z

From: Qiushi Wu <wu000273@umn.edu>

[ 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@umn.edu
Signed-off-by: Qiushi Wu <wu000273@umn.edu>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 e42909524deed..379925fc49d4e 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