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From:   Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
To:     bhelgaas@google.com
Cc:     linux-pci@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
        linux-kernel@vger.kernel.org,
        Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Subject: [PATCH 1/2] pci: rpadlpar: fix leaked device_node references in add/remove paths
Date:   Fri, 22 Mar 2019 13:27:21 -0500
Message-Id: <20190322182722.8255-1-tyreld@linux.vnet.ibm.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

The find_dlpar_node() helper returns a device node with its reference
incremented. Both the add and remove paths use this helper for find the
appropriate node, but fail to release the reference when done.

Annotate the find_dlpar_node() helper with a comment about the incremented
reference count, and call of_node_put() on the obtained device_node in the
add and remove paths. Also, fixup a reference leak in the find_vio_slot()
helper where we fail to call of_node_put() on the vdevice node after we
iterate over its children.

Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
---
 drivers/pci/hotplug/rpadlpar_core.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/pci/hotplug/rpadlpar_core.c b/drivers/pci/hotplug/rpadlpar_core.c
index e2356a9c7088..182f9e3443ee 100644
--- a/drivers/pci/hotplug/rpadlpar_core.c
+++ b/drivers/pci/hotplug/rpadlpar_core.c
@@ -51,6 +51,7 @@ static struct device_node *find_vio_slot_node(char *drc_name)
 		if (rc == 0)
 			break;
 	}
+	of_node_put(parent);
 
 	return dn;
 }
@@ -71,6 +72,7 @@ static struct device_node *find_php_slot_pci_node(char *drc_name,
 	return np;
 }
 
+/* Returns a device_node with its reference count incremented */
 static struct device_node *find_dlpar_node(char *drc_name, int *node_type)
 {
 	struct device_node *dn;
@@ -306,6 +308,7 @@ int dlpar_add_slot(char *drc_name)
 			rc = dlpar_add_phb(drc_name, dn);
 			break;
 	}
+	of_node_put(dn);
 
 	printk(KERN_INFO "%s: slot %s added\n", DLPAR_MODULE_NAME, drc_name);
 exit:
@@ -439,6 +442,7 @@ int dlpar_remove_slot(char *drc_name)
 			rc = dlpar_remove_pci_slot(drc_name, dn);
 			break;
 	}
+	of_node_put(dn);
 	vm_unmap_aliases();
 
 	printk(KERN_INFO "%s: slot %s removed\n", DLPAR_MODULE_NAME, drc_name);
-- 
2.12.3