Description
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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 6.19 | 7.2.13 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 7.2.13-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | linux | 7.3.0-10.10 | — |
| Ubuntu 26.10 | linux-aws +4 | 7.3.0-1004.4 | — |
| Ubuntu 26.10 | linux-azure-fde | 7.3.0-1004.5 | — |
| Ubuntu 26.10 | linux-riscv +1 | 7.3.0-10.10.1 | — |
| Ubuntu 26.04 LTS | linux +14 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-riscv +33 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 +1 | No fix yet | — |
Advisories 1
- WID-SEC-2026-4224 Linux Kernel: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff BSI CERT-Bund (WID) · Nov 12, 2026