CVE-2019-6454

An issue was discovered in sd-bus in systemd 239. bus_process_object() in
libsystemd/sd-bus/bus-objects.c allocates a variable-length stack buffer
for temporarily storing the object path of incoming D-Bus messages. An
unprivileged local user can exploit this by sending a specially crafted
message to PID1, causing the stack pointer to jump over the stack guard
pages into an unmapped memory region and trigger a denial of service
(systemd PID1 crash and kernel panic).