ACPI / hotplug / PCI: Fix reference count leak in enable_slot()

stable inclusion
from stable-5.10.39
commit dd6ba896ffa7e26872fe2daaf3abd25b66f47bd1
bugzilla: 51881
CVE: NA

--------------------------------

[ Upstream commit 3bbfd319 ]

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.comSigned-off-by: NFeilong Lin <linfeilong@huawei.com>
Signed-off-by: NZhiqiang Liu <liuzhiqiang26@huawei.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/pci/hotplug/acpiphp_glue.c

@@ -533,6 +533,7 @@ static void enable_slot(struct acpiphp_slot *slot, bool bridge)
 			slot->flags &= ~SLOT_ENABLED;
 			continue;
 		}
+		pci_dev_put(dev);
 	}
 }