diff --git a/drivers/firmware/efi/libstub/tpm.c b/drivers/firmware/efi/libstub/tpm.c
index d31ea3f351d8..a5c6c4f163fc 100644
--- a/drivers/firmware/efi/libstub/tpm.c
+++ b/drivers/firmware/efi/libstub/tpm.c
@@ -124,6 +124,9 @@ static void efi_retrieve_tcg2_eventlog(int version, efi_physical_addr_t log_loca
 			event_size = __calc_tpm2_event_size(header,
 						   (void *)(long)log_location,
 						   false);
+			/* If calc fails this is a malformed log */
+			if (!event_size)
+				break;
 			final_events_size += event_size;
 			i--;
 		}