From d4d17ce4235ffd89e081250df94ace8054c3436b Mon Sep 17 00:00:00 2001
From: Andreas Kling <awesomekling@gmail.com>
Date: Wed, 15 Jan 2020 22:10:38 +0100
Subject: [PATCH] Kernel: Trying to sys$link() a directory should fail with
 EPERM

---
 Kernel/FileSystem/VirtualFileSystem.cpp | 3 +++
 Userland/test_io.cpp                    | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/Kernel/FileSystem/VirtualFileSystem.cpp b/Kernel/FileSystem/VirtualFileSystem.cpp
index 472bdc3fed..d9d0a9cea2 100644
--- a/Kernel/FileSystem/VirtualFileSystem.cpp
+++ b/Kernel/FileSystem/VirtualFileSystem.cpp
@@ -521,6 +521,9 @@ KResult VFS::link(StringView old_path, StringView new_path, Custody& base)
     if (!parent_inode.metadata().may_write(current->process()))
         return KResult(-EACCES);
 
+    if (old_inode.is_directory())
+        return KResult(-EPERM);
+
     return parent_inode.add_child(old_inode.identifier(), FileSystemPath(new_path).basename(), old_inode.mode());
 }
 
diff --git a/Userland/test_io.cpp b/Userland/test_io.cpp
index 02a7053f27..e24fd0bfa5 100644
--- a/Userland/test_io.cpp
+++ b/Userland/test_io.cpp
@@ -255,5 +255,7 @@ int main(int, char**)
     test_eoverflow();
     test_rmdir_while_inside_dir();
 
+    EXPECT_ERROR_2(EPERM, link, "/", "/home/anon/lolroot");
+
     return 0;
 }