From 8ec556e603ed5c21796409b5b487cbf9bf28751f Mon Sep 17 00:00:00 2001
From: 6h057 <15034695+omarsy@users.noreply.github.com>
Date: Wed, 30 Oct 2024 22:56:47 +0100
Subject: [PATCH] fix(gnovm): forbid star expression when value is nil (#3053)

close: #3052
<!-- please provide a detailed description of the changes made in this
pull request. -->

<details><summary>Contributors' checklist...</summary>

- [ ] Added new tests, or not needed, or not feasible
- [ ] Provided an example (e.g. screenshot) to aid review or the PR is
self-explanatory
- [ ] Updated the official documentation or not needed
- [ ] No breaking changes were made, or a `BREAKING CHANGE: xxx` message
was included in the description
- [ ] Added references to related issues and PRs
- [ ] Provided any useful hints for running manual tests
</details>
---
 gnovm/pkg/gnolang/preprocess.go | 3 +++
 gnovm/tests/files/ptr10.gno     | 8 ++++++++
 2 files changed, 11 insertions(+)
 create mode 100644 gnovm/tests/files/ptr10.gno

diff --git a/gnovm/pkg/gnolang/preprocess.go b/gnovm/pkg/gnolang/preprocess.go
index 10c55979520..a7a1e15bbf3 100644
--- a/gnovm/pkg/gnolang/preprocess.go
+++ b/gnovm/pkg/gnolang/preprocess.go
@@ -1760,6 +1760,9 @@ func preprocess1(store Store, ctx BlockNode, n Node) Node {
 			// TRANS_LEAVE -----------------------
 			case *StarExpr:
 				xt := evalStaticTypeOf(store, last, n.X)
+				if xt == nil {
+					panic(fmt.Sprintf("invalid operation: cannot indirect nil"))
+				}
 				if xt.Kind() != PointerKind && xt.Kind() != TypeKind {
 					panic(fmt.Sprintf("invalid operation: cannot indirect %s (variable of type %s)", n.X.String(), xt.String()))
 				}
diff --git a/gnovm/tests/files/ptr10.gno b/gnovm/tests/files/ptr10.gno
new file mode 100644
index 00000000000..807fc149808
--- /dev/null
+++ b/gnovm/tests/files/ptr10.gno
@@ -0,0 +1,8 @@
+package main
+
+func main() {
+	println(*nil)
+}
+
+// Error:
+// main/files/ptr10.gno:4:10: invalid operation: cannot indirect nil