# \[PATCH AUTOSEL 4.4 2/4\] ACPI / hotplug / PCI: Fix reference count leak in enable\_slot()

- From: Sasha Levin \<sashal@kernel.org\>
- Date: 2021-05-12 19:57:56 
- List: stable
- Page: https://ratatoskr.run/stable/2021/05/1376008
- Thread: https://ratatoskr.run/stable/2021/05/1376005/t.md

```text
From: Feilong Lin <redacted>

[ 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@huawei.com
Signed-off-by: Feilong Lin <redacted>
Signed-off-by: Zhiqiang Liu <redacted>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <redacted>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 6727471ea5b4..d0f5c526c8e6 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);
 			continue;
 		}
+		pci_dev_put(dev);
 	}
 }
 
-- 
2.30.2

```
