From 51e304f10f6a184f39f1f69d2f0d52e7cd9e5347 Mon Sep 17 00:00:00 2001
From: acqn <acqn163@outlook.com>
Date: Mon, 18 Sep 2023 16:44:04 +0800
Subject: [PATCH] Added check for total arguments size for variadic functions.

---
 src/cc65/expr.c    |  4 ++++
 test/err/bug2144.c | 13 +++++++++++++
 2 files changed, 17 insertions(+)
 create mode 100644 test/err/bug2144.c

diff --git a/src/cc65/expr.c b/src/cc65/expr.c
index 47a05eca0..37af494b5 100644
--- a/src/cc65/expr.c
+++ b/src/cc65/expr.c
@@ -1035,6 +1035,10 @@ static void FunctionCall (ExprDesc* Expr)
     /* Parse the argument list and pass them to the called function */
     ArgSize = FunctionArgList (Func, IsFastcall, Expr);
 
+    if (ArgSize > 0xFF && (Func->Flags & FD_VARIADIC) != 0) {
+        Error ("Total size of all arguments passed to a variadic function cannot exceed 255 bytes");
+    }
+
     /* We need the closing paren here */
     ConsumeRParen ();
 
diff --git a/test/err/bug2144.c b/test/err/bug2144.c
new file mode 100644
index 000000000..eb27d672b
--- /dev/null
+++ b/test/err/bug2144.c
@@ -0,0 +1,13 @@
+/* Bug #2144 - Maximum parameter size is not checked for variadic functions */
+
+void a(...) {}
+
+void b()
+{
+    /* Argument size > 255 */
+    a(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L,
+      1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L,
+      1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L,
+      1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L,
+      1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L);
+}