From 62a8cfd5fed1380331b10d20fbb7b08f206cf541 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alex=20R=C3=B8nne=20Petersen?= <alex@alexrp.com>
Date: Tue, 14 Oct 2025 23:07:22 +0200
Subject: [PATCH] std.debug: fix an invalid read in StackIterator.next()

We're overwriting the memory that unwind_context sits in, so we need to do the
getFp() call earlier.
---
 lib/std/debug.zig | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/std/debug.zig b/lib/std/debug.zig
index 8501df175a..83322e8a6e 100644
--- a/lib/std/debug.zig
+++ b/lib/std/debug.zig
@@ -925,7 +925,8 @@ const StackIterator = union(enum) {
                 const di_gpa = getDebugInfoAllocator();
                 const ret_addr = di.unwindFrame(di_gpa, unwind_context) catch |err| {
                     const pc = unwind_context.pc;
-                    it.* = .{ .fp = unwind_context.getFp() };
+                    const fp = unwind_context.getFp();
+                    it.* = .{ .fp = fp };
                     return .{ .switch_to_fp = .{
                         .address = pc,
                         .err = err,