In a recent security advisory, Salvatore Bonaccorso writes that the last Linux kernel update released for Debian GNU/Linux 9 “Stretch” to mitigate the L1 Terminal Fault (L1TF) security vulnerabilities is causing boot failures for users on the ARM architecture. Also known as Foreshadow, these security vulnerabilities are similar to the Spectre security vulnerabilities and allow an attacker that has access to an unprivileged process to read the memory from arbitrary addresses that aren’t controlled by users, including from the kernel.