Check env stack length before OP_SETUPVAR; ref #3643

matz · matz · commit e0931126ffcf · 2017-05-25T14:12:16.000+09:00
diff --git a/src/vm.c b/src/vm.c
@@ -1084,8 +1084,11 @@ mrb_vm_exec(mrb_state *mrb, struct RProc *proc, mrb_code *pc)
       if (e) {
         mrb_value *regs_a = regs + GETARG_A(i);
         int idx = GETARG_B(i);
-        e->stack[idx] = *regs_a;
-        mrb_write_barrier(mrb, (struct RBasic*)e);
+
+        if (idx < MRB_ENV_STACK_LEN(e)) {
+          e->stack[idx] = *regs_a;
+          mrb_write_barrier(mrb, (struct RBasic*)e);
+        }
       }
       NEXT;
     }

Original file line number	Diff line number	Diff line change
`@@ -1084,8 +1084,11 @@ mrb_vm_exec(mrb_state mrb, struct RProc proc, mrb_code *pc)`
`1084`	`1084`	`if (e) {`
`1085`	`1085`	`mrb_value *regs_a = regs + GETARG_A(i);`
`1086`	`1086`	`int idx = GETARG_B(i);`
`1087`		`- e->stack[idx] = *regs_a;`
`1088`		`- mrb_write_barrier(mrb, (struct RBasic*)e);`
	`1087`	`+`
	`1088`	`+ if (idx < MRB_ENV_STACK_LEN(e)) {`
	`1089`	`+ e->stack[idx] = *regs_a;`
	`1090`	`+ mrb_write_barrier(mrb, (struct RBasic*)e);`
	`1091`	`+ }`
`1089`	`1092`	`}`
`1090`	`1093`	`NEXT;`
`1091`	`1094`	`}`