From 92cee5bdf51a8763d50f6ccac42aeda3ef86a0cb Mon Sep 17 00:00:00 2001
From: Ben Wiederhake <BenWiederhake.GitHub@gmx.de>
Date: Sun, 31 Jan 2021 13:28:18 +0100
Subject: [PATCH] Kernel: Demonstrate crash for invalid pointers

---
 .../Kernel/invalid-path-pointer-assert.cpp    | 56 +++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 Userland/Tests/Kernel/invalid-path-pointer-assert.cpp

diff --git a/Userland/Tests/Kernel/invalid-path-pointer-assert.cpp b/Userland/Tests/Kernel/invalid-path-pointer-assert.cpp
new file mode 100644
index 0000000000..fe503753d1
--- /dev/null
+++ b/Userland/Tests/Kernel/invalid-path-pointer-assert.cpp
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2021, Ben Wiederhake <BenWiederhake.GitHub@gmx.de>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <Kernel/API/Syscall.h>
+#include <errno.h>
+#include <stdio.h>
+#include <sys/stat.h>
+
+int main()
+{
+    struct stat statbuf;
+    // stat(3) would call strlen, and we can't have that.
+    Syscall::SC_stat_params params {
+        // Hey Kernel, please try to read the path from this totally valid location!
+        { (const char*)0xc000dead, 50 },
+        &statbuf, false
+    };
+    int rc = syscall(SC_stat, &params);
+
+    if (rc == 0) {
+        printf("stat passed?!\n");
+        printf("FAIL\n");
+        return 1;
+    }
+    if (rc != EFAULT) {
+        printf("error other than EFAULT?! rc = %d\n", rc);
+        printf("FAIL\n");
+        return 1;
+    }
+
+    printf("PASS\n");
+    return 0;
+}