Intel has admitted that PCs and servers are experiencing unexpected reboots after applying a patch designed to address the Spectre and Meltdown processor flaws. Spectre and Meltdown are design flaws in modern CPUs that could allow hackers to bypass system protections on a wide range of devices, allowing attackers to read sensitive information, such as passwords, from memory. Intel began making software and firmware updates available to mitigate attacks exploiting these flaws last week, pushing them out via system manufacturers. However, yesterday the chip maker admitted these updates were causing certain computers to unexpectedly reboot. The random reboots appear to be affecting both PCs and servers that use Intel Broadwell and Haswell processors. "We are working quickly with these customers to understand, diagnose and address this reboot issue. If this requires a revised firmware update from Intel, we will distribute that update through the normal channels," wrote Navin Shenoy, executive vice president and general manager of the Data Center Group at Intel. Despite the issues, Shenoy says that computer users and admins should "continue to apply updates recommended by their system and operating system providers". While tech firms have been preparing updates to mitigate the Spectre and Meltdown flaws for months, details of the vulnerabilities leaked out early. In the rush to issue patches there have been other instances of Spectre and Meltdown updates causing problems of their own. Microsoft recently said that Windows PCs won't receive any further security updates until third-party AV software is verified as compatible with Windows patches for Spectre and Meltdown. And chipmaker AMD has been working with Microsoft to resolve problems after the patches caused PCs running on some older AMD Opteron, Athlon and AMD Turion X2 Ultra processors to refuse to boot. AMD said yesterday the issue should be resolved shortly. AMD also announced that, starting this week, it will address the branch target injection exploit for Spectre by making microcode updates available for its Ryzen and Epyc processors. Updates for older processors will follow in the "coming weeks", with all updates being made available via OS vendors and system manufacturers. The Meltdown flaw doesn't affect AMD processors. As well as triggering undesirable behaviour the Spectre patches are degrading machine performance, particularly for older processors. Microsoft said earlier this week that people running computers on 2015-era Intel Haswell or earlier processors would see the biggest performance slowdown, particularly if they weren't using Windows 10. Those running Windows 10 systems on newer CPUs would see minimal impact, it said. Microsoft cautioned the performance of Windows Server systems could suffer a more significant impact, "especially in any IO-intensive application". Intel has also published data, gathered both from users and its own synthetic benchmarks, which identified a real-world performance hit of between about six and eight percent across all systems. Like Microsoft, it found that computers running on 8th-generation processors suffered a smaller impact than those running 7th- or 6th-generation CPUs. Apple claims that performance of Macs, iPhones and iPads is largely unaffected by the patches, stating "our testing with public benchmarks has shown that the changes in the December 2017 updates resulted in no measurable reduction in the performance of macOS and iOS as measured by the GeekBench 4 benchmark, or in common Web browsing benchmarks". Major cloud providers, AWS, Google and Microsoft say that, for the majority of workloads, customers should not notice a difference in performance following the updates. However, there have been reports from some customers of a drop off. AWS customer Epic Games attributed a more than 20 percent spike in CPU load on a cloud server hosting games of Fortnite to the impact of the Spectre and Meltdown patches. Also see
Intel is running into problems protecting its chips from the major Meltdown and Spectre vulnerabilities that became public last week. The company has been warning customers of three specific flaws in a recent firmware update and recommending that customers hold off installing the patch, according to emails first reported by The Wall Street Journal. According to a follow-up announcement by Intel, the issue may cause reboot issues in systems running older Haswell chips. Intel has been aware of the Spectre issues since June, but rewriting processor firmware to address the vulnerability proved to be a significant challenge. The company has committed to protecting 90 percent of its CPUs produced in the last five years, with patches to be deployed by January 15th, but technical issues have marred those patches across the board. Earlier this week, Microsoft had to halt the deployment of AMDs Spectre patches after they rendered some computers unbootable. Patching the CPU firmware is widely seen as the most technically difficult element of Spectre recovery, far more challenging than the operating system or browser patches that were deployed last week. Its also the patch most likely to slow computers down, although its still unclear how significant the performance hit will be. Intels recent benchmarks show less than 5 percent slowdowns on recent processors, but those tests did not extend to the Haswell processors affected by todays issues.