Microsoft's latest Insider build of Windows 10 has crippled the 64-bit version of Google's Chrome browser.
After Microsoft issued build 10525 Tuesday, Chrome users began reporting on Google's help forum, on Reddit and elsewhere, that their browsers were consistently crashing.
"I'm on Windows Insider Preview and just upgraded to Windows 10 Pro Build 10525 which was just released to Insider Preview members and Google Chrome doesn't work in this build," wrote someone identified as ksweeley on a thread in the Chrome support forum. "All versions (stable, beta, developer and Canary) do not work, I get the 'Aw Snap!' page ... and no pages will load."
A much longer thread on Reddit also tackled the problem. "I tried reinstalling Chrome, I even tried installing a different branch (the beta one), but I just cannot get it to work," added James1o1o.
According to the reports, and confirmed by Computerworld, the 64-bit version of Chrome, which made it to the Stable channel a year ago, does not run on Windows 10 build 10525. The 32-bit browser, however, works fine.
An entry in the Chromium bug tracker -- Chromium is the open-source project that feeds code into Chrome -- was logged yesterday.
"Cutting through the noise, it looks like the sandbox is breaking in the Win10 10525 previews for 64-bit Chrome," acknowledged Justin Schuh, a Google software engineer, in one message on the bug tracker. "If Firefox e10s is also breaking as well, then it must be something pretty basic, like our hooks breaking under CFG."
Chrome relies on an anti-exploitation technology, colloquially called a "sandbox," to isolate the browser's processes as part of an effort to stop or at least impede attackers leveraging a vulnerability, hopefully blocking them from planting malware on a device. Schuh's reference to "e10s" was to Mozilla's work on a sandboxing technology for its Firefox browser.
Schuh also linked to an associated entry in the bug tracker, which referred to requests by both Microsoft and Intel to Google to change Chrome "to work better with their ongoing ROP mitigation efforts."
ROP, for "return-oriented programming," is an exploit technique that has been a past focus of Microsoft's defensive efforts. ROP has a rich history: The Stuxnet worm, reportedly created by U.S. and Israeli coders to sabotage Iran's nuclear fuel enrichment facilities, made extensive use of ROP.
According to users on Reddit, the 64-bit version can be forced to run by appending "--no-sandbox" (without the quotation marks) to the Windows shortcut for Chrome. That, of course, also disables one of Chrome's most important defenses. Alternately, users can switch to 32-bit Chrome, or another browser.
Several on Reddit wondered whether the changes in build 10525 to Windows 10's memory management were behind the Chrome snafu. According to Microsoft, the build instigated a cache of compressed "pages," or contiguous memory blocks, that were stored in virtual memory rather than written to the device's physical memory or disk drive. The changes free up physical memory -- the actual RAM available on a device -- so that more apps can be maintained in the former for quick resuscitation and improves the OS's responsiveness.
Because the default download on Windows is for the 32-bit version, not everyone running Google's browser on Windows 10 build 10525 has been affected.