[Patch v4 3/7] acpi_memhotplug.c: fix memory leak when memory device is unbound from the module acpi_memhotplug

[Wen Congyang <wency@xxxxxxxxxxxxxx>]

We allocate memory to store acpi_memory_info, so we should free it before
freeing mem_device.

CC: David Rientjes <rientjes@xxxxxxxxxx>
CC: Jiang Liu <liuj97@xxxxxxxxx>
CC: Len Brown <len.brown@xxxxxxxxx>
CC: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
CC: Paul Mackerras <paulus@xxxxxxxxx>
CC: Christoph Lameter <cl@xxxxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
CC: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
CC: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
CC: Rafael J. Wysocki <rjw@xxxxxxx>
CC: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Signed-off-by: Wen Congyang <wency@xxxxxxxxxxxxxx>
---
 drivers/acpi/acpi_memhotplug.c | 31 +++++++++++++++++++++++--------
 1 file changed, 23 insertions(+), 8 deletions(-)

diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index e573e87..5e5ac80 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -131,12 +131,22 @@ acpi_memory_get_resource(struct acpi_resource *resource, void *context)
 	return AE_OK;
 }
 
+static void
+acpi_memory_free_device_resources(struct acpi_memory_device *mem_device)
+{
+	struct acpi_memory_info *info, *n;
+
+	mutex_lock(&mem_device->list_lock);
+	list_for_each_entry_safe(info, n, &mem_device->res_list, list)
+		kfree(info);
+	INIT_LIST_HEAD(&mem_device->res_list);
+	mutex_unlock(&mem_device->list_lock);
+}
+
 static int
 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
 {
 	acpi_status status;
-	struct acpi_memory_info *info, *n;
-
 
 	if (!list_empty(&mem_device->res_list))
 		return 0;
@@ -144,11 +154,7 @@ acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
 	status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
 				     acpi_memory_get_resource, mem_device);
 	if (ACPI_FAILURE(status)) {
-		mutex_lock(&mem_device->list_lock);
-		list_for_each_entry_safe(info, n, &mem_device->res_list, list)
-			kfree(info);
-		INIT_LIST_HEAD(&mem_device->res_list);
-		mutex_unlock(&mem_device->list_lock);
+		acpi_memory_free_device_resources(mem_device);
 		return -EINVAL;
 	}
 
@@ -447,6 +453,15 @@ static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
 	return;
 }
 
+static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
+{
+	if (!mem_device)
+		return;
+
+	acpi_memory_free_device_resources(mem_device);
+	kfree(mem_device);
+}
+
 static int acpi_memory_device_add(struct acpi_device *device)
 {
 	int result;
@@ -512,7 +527,7 @@ static int acpi_memory_device_remove(struct acpi_device *device, int type)
 	if (result)
 		return result;
 
-	kfree(mem_device);
+	acpi_memory_device_free(mem_device);
 
 	return 0;
 }
-- 
1.8.0

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