WMI: properly cleanup devices to avoid crashes

We need to remove devices that we destroy from the list, otherwise
we'll crash if there are more than one "_WDG" methods in DSDT.

This fixes https://bugzilla.kernel.org/show_bug.cgi?id=32052

Tested-by: Ilya Tumaykin <librarian_rus@yahoo.com>
Cc: stable@kernel.org
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Acked-by: Carlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index f23d5a84e7b1..9b88be42b6cd 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -754,9 +754,13 @@ static void wmi_free_devices(void)
         struct wmi_block *wblock, *next;
 
         /* Delete devices for all the GUIDs */
-        list_for_each_entry_safe(wblock, next, &wmi_block_list, list)
+        list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
+                list_del(&wblock->list);
                 if (wblock->dev.class)
                         device_unregister(&wblock->dev);
+                else
+                        kfree(wblock);
+        }
 }
 
 static bool guid_already_parsed(const char *guid_string)