UBUNTU-CVE-2026-80927: Medium severity ubuntu/linux-hwe-edge vulnerability

In the Linux kernel, the following vulnerability has been resolved: timekeeping: Check the return value of tkgetauxts64 in doadjtimex() If the auxiliary clock is disabled during tkgetauxts64() but is enabled before tks->clockvalid is checked, then uninitialized stackdata will be used in the calculations and indirectly leaked to userspace. The same race window also exists after this change and also for the core timekeeper. But in these cases the only effect would be incorrect adjustments and this is userspace's responsibility to avoid this.