Currently `RestrictFileSystemAccess` isn't trying hard enough to enforce
W^X and thus there are still places where an executable and writable
mapping can be created:
* `/proc/<pid>/mem` `FOLL_FORCE` writes
* `PTRACE_POKE{TEXT,DATA}` `FOLL_FORCE` writes
* `MAP_PRIVATE | MAP_EXECUTABLE` memory mappings
Let's block all of these mechanisms. Do note that
`RestrictFileSystemAccess` is still in very active development and also
cannot meaningfully be used on general purpose distros and systems.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Christian Brauner
9b62fd169e