A cross-privilege Spectre v2 vulnerability allows attackers to bypass all deployed mitigations, including the recent Fine(IBT), and to leak arbitrary Linux kernel memory on Intel systems.
https://www.kb.cert.org/vuls/id/155143
https://github.com/vusec/inspectre-gadget?tab=readme-ov-file
http://xenbits.xen.org/xsa/advisory-456.html