efi_loader: check parameters of CreateEvent

Rigorously check the TPL level and the event type.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>

diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index 46c8ecd187fe7d906eb6a442b956337020e13d1b..86cb9ba479a585c27af948e15cc08b480f751fe8 100644 (file)
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -190,6 +190,25 @@ static void efi_queue_event(struct efi_event *event, bool check_tpl)
        event->is_queued = false;
 }
 
+/**
+ * is_valid_tpl() - check if the task priority level is valid
+ *
+ * @tpl:               TPL level to check
+ * ReturnValue:                status code
+ */
+efi_status_t is_valid_tpl(efi_uintn_t tpl)
+{
+       switch (tpl) {
+       case TPL_APPLICATION:
+       case TPL_CALLBACK:
+       case TPL_NOTIFY:
+       case TPL_HIGH_LEVEL:
+               return EFI_SUCCESS;
+       default:
+               return EFI_INVALID_PARAMETER;
+       }
+}
+
 /**
  * efi_signal_event() - signal an EFI event
  * @event:     event to signal
@@ -592,11 +611,21 @@ efi_status_t efi_create_event(uint32_t type, efi_uintn_t notify_tpl,
        if (event == NULL)
                return EFI_INVALID_PARAMETER;
 
-       if ((type & EVT_NOTIFY_SIGNAL) && (type & EVT_NOTIFY_WAIT))
+       switch (type) {
+       case 0:
+       case EVT_TIMER:
+       case EVT_NOTIFY_SIGNAL:
+       case EVT_TIMER | EVT_NOTIFY_SIGNAL:
+       case EVT_NOTIFY_WAIT:
+       case EVT_TIMER | EVT_NOTIFY_WAIT:
+       case EVT_SIGNAL_EXIT_BOOT_SERVICES:
+       case EVT_SIGNAL_VIRTUAL_ADDRESS_CHANGE:
+               break;
+       default:
                return EFI_INVALID_PARAMETER;
+       }
 
-       if ((type & (EVT_NOTIFY_SIGNAL | EVT_NOTIFY_WAIT)) &&
-           notify_function == NULL)
+       if (is_valid_tpl(notify_tpl) != EFI_SUCCESS)
                return EFI_INVALID_PARAMETER;
 
        evt = calloc(1, sizeof(struct efi_event));