[PATCH 4.9 231/240] ACPI / hotplug / PCI: Fix reference count leak in enable_slot()

From: Greg Kroah-Hartman
Date: Thu May 20 2021 - 07:24:29 EST

From: Feilong Lin <linfeilong@xxxxxxxxxx>

[ Upstream commit 3bbfd319034ddce59e023837a4aa11439460509b ]

In enable_slot(), if pci_get_slot() returns NULL, we clear the SLOT_ENABLED
flag. When pci_get_slot() finds a device, it increments the device's
reference count. In this case, we did not call pci_dev_put() to decrement
the reference count, so the memory of the device (struct pci_dev type) will
eventually leak.

Call pci_dev_put() to decrement its reference count when pci_get_slot()
returns a PCI device.

Link: https://lore.kernel.org/r/b411af88-5049-a1c6-83ac-d104a1f429be@xxxxxxxxxx
Signed-off-by: Feilong Lin <linfeilong@xxxxxxxxxx>
Signed-off-by: Zhiqiang Liu <liuzhiqiang26@xxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
drivers/pci/hotplug/acpiphp_glue.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index 7f2b9ef185e4..f154b05f467f 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -538,6 +538,7 @@ static void enable_slot(struct acpiphp_slot *slot)
slot->flags &= (~SLOT_ENABLED);
+ pci_dev_put(dev);