Not long after it started issuing firmware patches in response to the disclosure Meltdown and Spectre flaw, Intel acknowledged that some users were experiencing unwanted reboots seemingly caused by the fix. In a new blog post, Intel says that it has now identified the root cause of the issue, which impacts machines with Broadwell and Haswell CPUs, and is testing a fix with partners.
We have now identified the root cause for Broadwell and Haswell platforms, and made good progress in developing a solution to address it. Over the weekend, we began rolling out an early version of the updated solution to industry partners for testing, and we will make a final release available once that testing has been completed.
Now that a fix is in testing, Intel is recommending that "OEMs, cloud service providers, system manufacturers, software vendors and end users stop deployment of current versions" to limit the impact of unexpected reboots with current updates. Assuming testing goes well, we can likely expect Intel to release the fix more broadly. Intel says that it expects to share more details on its testing later this week.
Though that's potentially good news for Haswell and Broadwell systems, It's unclear where those with newer CPUs stand. Last week, Intel revealed that systems based on Ivy Bridge, Sandy Bridge, Skylake, and Kaby Lake CPUs are also impacted by unwanted reboots. In a separate security bulletin Intel says that the progress it has made in identifying the cause for Broadwell and Haswell systems will help it "address issues on other platforms."
Aside from Intel's own fixes, a number of other companies have rolled out various remedies of their own. Microsoft was among the first, releasing an emergency patch for Windows users and a set of firmware updates for Surface devices. AMD also announced optional patches of its own, despite its claims that the exploits pose a "near-zero" risk to its hardware. Similarly, NVIDIA joined the fray with a set of software patches for its GPU drivers.
If you're curious whether your PC is affected by Spectre or Meltdown, a tool called InSpectre can quickly identify vulnerabilities on your system.