shim: Don't parse load options if invoked from removable media path

We see various reports of boot failures because the generated
boot entries contain garbage/tagging that we do not expect, and
that we then parse as a second stage boot loader.

1 files changed, 11 insertions, 0 deletions

diff --git a/shim.c b/shim.c
index 2bc77b0d..66d91b5b 100644
--- a/shim.c
+++ b/shim.c
@@ -1170,6 +1170,17 @@ EFI_STATUS set_second_stage (EFI_HANDLE image_handle)
 		return efi_status;
 	}
 
+#if defined(DISABLE_REMOVABLE_LOAD_OPTIONS)
+	/*
+	 * boot services build very strange load options, and we might misparse them,
+	 * causing boot failures on removable media.
+	 */
+	if (is_removable_media_path(li)) {
+		dprint("Invoked from removable media path, ignoring boot options");
+		return EFI_SUCCESS;
+	}
+#endif
+
 	efi_status = parse_load_options(li);
 	if (EFI_ERROR(efi_status)) {
 		perror (L"Failed to get load options: %r\n", efi_status);