From 8baf0f6340c92a542d070a9490d286a4009b8b29 Mon Sep 17 00:00:00 2001
From: Jamiras <jamirasmt@gmail.com>
Date: Wed, 4 Mar 2020 16:36:33 -0700
Subject: [PATCH] prevent buffer overflow when encountering an unknown macro

---
 cheevos-new/cheevos.c                     |  6 +++---
 deps/rcheevos/src/rcheevos/richpresence.c | 18 ++++++++++++++----
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/cheevos-new/cheevos.c b/cheevos-new/cheevos.c
index d9d7dacc36..3520c94427 100644
--- a/cheevos-new/cheevos.c
+++ b/cheevos-new/cheevos.c
@@ -666,7 +666,7 @@ static int rcheevos_parse(const char* json)
       lboard->format = rc_parse_format(lboard->info->format);
    }
 
-   if (rcheevos_locals.patchdata.richpresence_script)
+   if (rcheevos_locals.patchdata.richpresence_script && *rcheevos_locals.patchdata.richpresence_script)
    {
       int buffer_size = rc_richpresence_size(rcheevos_locals.patchdata.richpresence_script);
       if (buffer_size <= 0)
@@ -681,8 +681,8 @@ static int rcheevos_parse(const char* json)
       }
       else
       {
-         char *buffer = (char*)malloc(buffer_size);
-         rcheevos_locals.richpresence.richpresence = rc_parse_richpresence(buffer, rcheevos_locals.patchdata.richpresence_script, NULL, 0);
+         char *rp_buffer = (char*)malloc(buffer_size);
+         rcheevos_locals.richpresence.richpresence = rc_parse_richpresence(rp_buffer, rcheevos_locals.patchdata.richpresence_script, NULL, 0);
       }
 
       rcheevos_locals.richpresence.evaluation[0] = '\0';
diff --git a/deps/rcheevos/src/rcheevos/richpresence.c b/deps/rcheevos/src/rcheevos/richpresence.c
index 0e8b4e70df..1f9d7c3470 100644
--- a/deps/rcheevos/src/rcheevos/richpresence.c
+++ b/deps/rcheevos/src/rcheevos/richpresence.c
@@ -8,7 +8,8 @@
 /* special formats only used by rc_richpresence_display_part_t.display_type. must not overlap other RC_FORMAT values */
 enum {
   RC_FORMAT_STRING = 101,
-  RC_FORMAT_LOOKUP = 102
+  RC_FORMAT_LOOKUP = 102,
+  RC_FORMAT_UNKNOWN_MACRO = 103
 };
 
 static const char* rc_parse_line(const char* line, const char** end) {
@@ -161,10 +162,15 @@ static rc_richpresence_display_t* rc_parse_richpresence_display_internal(const c
             *next = part;
             next = &part->next;
 
-            ptr = line;
+            /* find the closing parenthesis */
+            while (ptr < endline && *ptr != ')')
+              ++ptr;
+            if (*ptr == ')')
+              ++ptr;
 
-            part->display_type = RC_FORMAT_STRING;
-            part->text = rc_alloc_str(parse, "[Unknown macro]", 15);
+            /* assert: the allocated string is going to be smaller than the memory used for the parameter of the macro */
+            part->display_type = RC_FORMAT_UNKNOWN_MACRO;
+            part->text = rc_alloc_str(parse, line, ptr - line);
           }
         }
       }
@@ -422,6 +428,10 @@ int rc_evaluate_richpresence(rc_richpresence_t* richpresence, char* buffer, unsi
             }
             break;
 
+          case RC_FORMAT_UNKNOWN_MACRO:
+            chars = snprintf(ptr, buffersize, "[Unknown macro]%s", part->text);
+            break;
+
           default:
             value = rc_evaluate_value(&part->value, peek, peek_ud, L);
             chars = rc_format_value(ptr, buffersize, value, part->display_type);