shithub: choc

Download patch

ref: 118d869f5b104563284ac033e156a6bb85a4d642
parent: 005a79c6528d7b98c37f24e548e805f6435f0e36
author: Simon Howard <fraggle@soulsphere.org>
date: Thu Jan 4 20:27:11 EST 2018 

hexen: Add bounds checking for world variables.

There is a fixed number of world variables and the limit should not
be exceeded.


--- a/src/hexen/p_acs.c
+++ b/src/hexen/p_acs.c
@@ -900,6 +900,15 @@
     return var;
 }
 
+static int ReadWorldVar(void)
+{
+    int var = ReadCodeImmediate();
+    ACSAssert(var >= 0, "negative world variable: %d < 0", var);
+    ACSAssert(var < MAX_ACS_WORLD_VARS,
+              "invalid world variable: %d >= %d", var, MAX_ACS_WORLD_VARS);
+    return var;
+}
+
 //==========================================================================
 //
 // P-Code Commands
@@ -1185,8 +1194,7 @@
 
 static int CmdAssignWorldVar(void)
 {
-    WorldVars[LONG(*PCodePtr)] = Pop();
-    ++PCodePtr;
+    WorldVars[ReadWorldVar()] = Pop();
     return SCRIPT_CONTINUE;
 }
 
@@ -1204,8 +1212,7 @@
 
 static int CmdPushWorldVar(void)
 {
-    Push(WorldVars[LONG(*PCodePtr)]);
-    ++PCodePtr;
+    Push(WorldVars[ReadWorldVar()]);
     return SCRIPT_CONTINUE;
 }
 
@@ -1223,8 +1230,7 @@
 
 static int CmdAddWorldVar(void)
 {
-    WorldVars[LONG(*PCodePtr)] += Pop();
-    ++PCodePtr;
+    WorldVars[ReadWorldVar()] += Pop();
     return SCRIPT_CONTINUE;
 }
 
@@ -1242,8 +1248,7 @@
 
 static int CmdSubWorldVar(void)
 {
-    WorldVars[LONG(*PCodePtr)] -= Pop();
-    ++PCodePtr;
+    WorldVars[ReadWorldVar()] -= Pop();
     return SCRIPT_CONTINUE;
 }
 
@@ -1261,8 +1266,7 @@
 
 static int CmdMulWorldVar(void)
 {
-    WorldVars[LONG(*PCodePtr)] *= Pop();
-    ++PCodePtr;
+    WorldVars[ReadWorldVar()] *= Pop();
     return SCRIPT_CONTINUE;
 }
 
@@ -1280,8 +1284,7 @@
 
 static int CmdDivWorldVar(void)
 {
-    WorldVars[LONG(*PCodePtr)] /= Pop();
-    ++PCodePtr;
+    WorldVars[ReadWorldVar()] /= Pop();
     return SCRIPT_CONTINUE;
 }
 
@@ -1299,8 +1302,7 @@
 
 static int CmdModWorldVar(void)
 {
-    WorldVars[LONG(*PCodePtr)] %= Pop();
-    ++PCodePtr;
+    WorldVars[ReadWorldVar()] %= Pop();
     return SCRIPT_CONTINUE;
 }
 
@@ -1318,8 +1320,7 @@
 
 static int CmdIncWorldVar(void)
 {
-    ++WorldVars[LONG(*PCodePtr)];
-    ++PCodePtr;
+    ++WorldVars[ReadWorldVar()];
     return SCRIPT_CONTINUE;
 }
 
@@ -1337,8 +1338,7 @@
 
 static int CmdDecWorldVar(void)
 {
-    --WorldVars[LONG(*PCodePtr)];
-    ++PCodePtr;
+    --WorldVars[ReadWorldVar()];
     return SCRIPT_CONTINUE;
 }