CVE-2021-4440

In the Linux kernel, the following vulnerability has been resolved: x86/xen: Drop USERGSSYSRET64 paravirt call commit afd30525a659ac0ae0904f0cb4a2ca75522c3123 upstream. USERGSSYSRET64 is used to return from a syscall via SYSRET, but a Xen PV guest will nevertheless use the IRET hypercall, as ther...