Reviving the modprobe_path Technique: Overcoming search_binary_handler() Patch

Introduction This blog post introduces a new method for utilizing the Overwriting modprobe_path technique. Since this patch was merged last year, it is no longer possible to trigger modprobe_path in the Upstream kernel by executing dummy files. Overwriting modprobe_path The Overwriting modprobe_path technique is, in simple terms, a method for achieving privilege escalation by overwriting the modprobe_path symbol when an Arbitrary Address Write (AAW) primitive is available. Due to its simplicity and effectiveness, this technique has been widely used by kernel exploit developers over the past few years. Since there are already numerous blog posts explaining this technique in detail, I will only provide a brief summary before moving on. First, in kernel versions prior to v6.14-rc1 , when a user attempts to execute a dummy file starting with a magic number such as \xff\xff\xff\xff , the following call stack is triggered: sys_execve() => do_execve() => do_execveat_common() => bprm_ ... Read full article.