On Thu, Jun 05, 2025 at 11:06:38PM +0200, David Hildenbrand wrote: > Not sure if relevant, but consider the following: > > an app being controlled by another process using userfaultfd. > > The app itself can "escape" uffd control of the other process by simply > creating a userfaultfd and unregistering VMAs. IMHO it's okay if it's intentional by the child. E.g., even after this patch, the child, if intentional, can also mmap() a new VMA on top of the uffd tracked region to stop being trapped by the parent. The parent might still get a UNMAP event if registered, but it'll not be able to track the new VMAs mapped. Thanks, -- Peter Xu
