CVE-2026-99168

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> mshv_vtl: Check per-CPU register page before mmap<br /> <br /> Register-page setup is optional for each CPU. If allocation or<br /> registration fails, mshv_vtl_configure_reg_page() warns and leaves that<br /> CPU&amp;#39;s reg_page NULL, but initial context setup continues successfully.<br /> Meanwhile, successful setup on another CPU sets the global<br /> mshv_has_reg_page flag.<br /> <br /> mshv_vtl_fault() checks this global flag before selecting the requested<br /> CPU&amp;#39;s register page. With mixed setup results across online CPUs, the<br /> check passes even for a CPU with no register page, reaching<br /> get_page(NULL) when userspace faults in that mapping.<br /> <br /> Check the selected per-CPU register page before taking its reference and<br /> return VM_FAULT_SIGBUS if it is absent.