efi_loader: do not set invalid screen mode

EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL.SetMode() should return EFI_UNDEFINED if a
screen mode is not available.

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

diff --git a/lib/efi_loader/efi_console.c b/lib/efi_loader/efi_console.c
index 5560fc8deaa05a85ab439c6f2c4b9087b29ecd32..5109017796bd458dfcb5aa5acaee668bbf5a5c07 100644 (file)
--- a/lib/efi_loader/efi_console.c
+++ b/lib/efi_loader/efi_console.c
@@ -379,6 +379,10 @@ static efi_status_t EFIAPI efi_cout_set_mode(
 
        if (mode_number >= efi_con_mode.max_mode)
                return EFI_EXIT(EFI_UNSUPPORTED);
+
+       if (!efi_cout_modes[mode_number].present)
+               return EFI_EXIT(EFI_UNSUPPORTED);
+
        efi_con_mode.mode = mode_number;
        EFI_CALL(efi_cout_clear_screen(this));