`set_no_new_privs`¶

Overview¶

set_no_new_privs() enables the Linux no_new_privs attribute for the current process.

This is commonly required before applying unprivileged seccomp or Landlock restrictions.

Synopsis¶

[[nodiscard]] std::expected<void, int> set_no_new_privs() noexcept;

Description¶

Sets PR_SET_NO_NEW_PRIVS for the current process using prctl.

After this succeeds, the current process and its child processes cannot gain new privileges through operations such as execve() of set-user-ID or set-group-ID programs.

The function is equivalent to:

prctl(PR_SET_NO_NEW_PRIVS, 1L, 0L, 0L, 0L);

Returns¶

Returns an empty std::expected on success, or a positive errno value on failure.

Example¶

auto result = mylib::set_no_new_privs();

if (!result) {
    std::cerr << "set_no_new_privs failed: "
              << std::strerror(result.error()) << '\n';
    return 1;
}

or, using a helper such as unwrap_or_die:

unwrap_or_die(mylib::set_no_new_privs());

Notes¶

The no_new_privs attribute is inherited across fork() and execve().

Once set, it cannot be unset by the process.

set_no_new_privs¶