Catch overflow in header size

gap-system · Sep 25, 2023 · 412efb9 · 412efb9
1 parent 0fb705c
commit 412efb9
Show file tree

Hide file tree

Showing 2 changed files with 28 additions and 0 deletions.
diff --git a/src/code.c b/src/code.c
@@ -259,6 +259,10 @@ Stat NewStatOrExpr(CodeState * cs, UInt type, UInt size, UInt line)
     StatHeader * header = STAT_HEADER(cs, stat);
     header->line = line;
     header->size = size;
+    // check size fits inside header
+    if (header->size != size) {
+        ErrorQuit("function too large for parser", 0, 0);
+    }
     header->type = type;
     RegisterStatWithHook(GET_GAPNAMEID_BODY(cs->currBody), line, type);
     // return the new statement

diff --git a/tst/testinstall/function.tst b/tst/testinstall/function.tst
@@ -339,5 +339,29 @@ function ( x ) return ([ [ x ] ]{[ 1 ]}{[ 1 ]})[1, 1]; end
 gap> funcloop(x -> ([ [ x ] ]{[ 1 ]}{[ 1 ]}){[ 1 ]}); # EXPR_ELMS_LIST
 function ( x ) return ([ [ x ] ]{[ 1 ]}{[ 1 ]}){[ 1 ]}; end
 
+# Test functions with very large lists
+gap> funcstr := String(List([1..2097151], x -> x));;
+gap> funcstr := Concatenation("func := function() return ", funcstr, "; end;");;
+gap> Read(InputTextString(funcstr));;
+gap> func() = [1..2097151];
+true
+gap> funcstr := String(List([1..2097152], x -> x));;
+gap> funcstr := Concatenation("func := function() return ", funcstr, "; end;");;
+gap> Read(InputTextString(funcstr));;
+Error, function too large for parser
+
+# Test functions with very large records
+gap> r := rec();; for x in [1..2097150/2] do r.(x) := x; od;;
+gap> funcstr := String(r);;
+gap> funcstr := Concatenation("func := function() return ", funcstr, "; end;");;
+gap> Read(InputTextString(funcstr));;
+gap> func() = r;
+true
+gap> r := rec();; for x in [1..2097152/2] do r.(x) := x; od;;
+gap> funcstr := String(r);;
+gap> funcstr := Concatenation("func := function() return ", funcstr, "; end;");;
+gap> Read(InputTextString(funcstr));;
+Error, function too large for parser
+
 #
 gap> STOP_TEST("function.tst", 1);