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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Feilong Lin <linfeilong@huawei.com>,
        Zhiqiang Liu <liuzhiqiang26@huawei.com>,
        Bjorn Helgaas <bhelgaas@google.com>,
        "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.9 231/240] ACPI / hotplug / PCI: Fix reference count leak in enable_slot()
Date:   Thu, 20 May 2021 11:23:43 +0200
Message-Id: <20210520092116.457653477@linuxfoundation.org>
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References: <20210520092108.587553970@linuxfoundation.org>
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From: Feilong Lin <linfeilong@huawei.com>

[ 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 <linfeilong@huawei.com>
Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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 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);
 			continue;
 		}
+		pci_dev_put(dev);
 	}
 }
 
-- 
2.30.2