platform/x86: wmi: Fix error handling when creating devices

We have two memory leaks. If guid_already_parsed returned true, we leak
the wmi_block. If wmi_create_device failed, we leak the device.

Simplify the logic and fix both of them.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>

1 files changed, 15 insertions, 13 deletions

diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index f06b7c00339d..31c317fb65dc 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -757,6 +757,15 @@ static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
                 if (debug_dump_wdg)
                         wmi_dump_wdg(&gblock[i]);
 
+                /*
+                 * Some WMI devices, like those for nVidia hooks, have a
+                 * duplicate GUID. It's not clear what we should do in this
+                 * case yet, so for now, we'll just ignore the duplicate
+                 * for device creation.
+                 */
+                if (guid_already_parsed(device, gblock[i].guid))
+                        continue;
+
                 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
                 if (!wblock)
                         return -ENOMEM;
@@ -764,19 +773,12 @@ static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
                 wblock->acpi_device = device;
                 wblock->gblock = gblock[i];
 
-                /*
-                  Some WMI devices, like those for nVidia hooks, have a
-                  duplicate GUID. It's not clear what we should do in this
-                  case yet, so for now, we'll just ignore the duplicate
-                  for device creation.
-                */
-                if (!guid_already_parsed(device, gblock[i].guid)) {
-                        retval = wmi_create_device(wmi_bus_dev, &gblock[i],
-                                                   wblock, device);
-                        if (retval) {
-                                wmi_free_devices(device);
-                                goto out_free_pointer;
-                        }
+                retval = wmi_create_device(wmi_bus_dev, &gblock[i],
+                                           wblock, device);
+                if (retval) {
+                        put_device(&wblock->dev.dev);
+                        wmi_free_devices(device);
+                        goto out_free_pointer;
                 }
 
                 list_add_tail(&wblock->list, &wmi_block_list);