In the Linux kernel, the following vulnerability has been resolved:
um: time-travel: fix time corruption
In basic time-travel mode (without =inf-cpu or =ext), we still get timer interrupts. These can happen at arbitrary points in time, i.e. while in timer_read(), which pushes time forward just a little bit. Then, if we happen to get the interrupt after calculating the new time to push to, but before actually finishing that, the interrupt will set the time to a value thats incompatible with the forward, and well crash because time goes backwards when we do the forwarding.
Fix this by reading the time_travel_time, calculating the adjustment, and doing the adjustment all with interrupts disabled.