CVE Catalog

CVE-2026-99168

Unknown
Published: Translated: NVD NIST

Summary

In the Linux kernel, mshv_vtl checks the global mshv_has_reg_page flag before selecting the requested CPU's register page. With mixed setup results across CPUs, the check passes even for a CPU with no register page, leading to get_page(NULL) when userspace faults in that mapping.

Risk Assessment

This can cause a kernel crash (oops/panic) or denial of service on systems using mshv_vtl when userspace triggers a fault on such a mapping.

Recommendation

Update the Linux kernel to a version containing the fix that checks the selected per-CPU register page before taking its reference and returns VM_FAULT_SIGBUS if absent.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

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

Vulnerability data from NVD (NIST) · CISA KEV · EPSS