Yesterday, Mac video professionals started reporting that their computers were crashing, attributing the issue to Avid’s Media Composer editor. However, it appeared that the problem occurred due to a piece of Google software (Version 184.108.40.206 of Google Keystone) which helps keeping the Chrome browser up-to-date.
“We recently discovered that a Chrome update may have shipped with a bug that damages the file system on MacOS machines,” Google wrote in a forum post.
“We’ve paused the release while we finalize a new update that addresses the problem.”
The Chrome update corrupted the computers’ file system which had Apple’s System Integrity Protection disabled, making it impossible to reboot.
System Integrity Protection is an Apple technology whose purpose is to ensure that malicious software doesn’t corrupt core system files. Known as SIP, the OS security feature helps “prevent potentially malicious software from modifying protected files and folders on your Mac.”
The issue also affects Macs that do not support SIP (pre-OS X El Capitan).
Being aware of the issue, Google advised the affected users on how to uninstall the Chrome update, and suggested that the majority of users may not be at risk at all.
“If you have not taken steps to disable System Integrity Protection and your computer is on OS X 10.9 or later, this issue cannot affect you,” the forum post states.
After running some tests, Google has issued commands for recovering the machines affected by the recent update:
chroot /Volumes/Macintosh\ HD [note: “Macintosh HD” is the default]
rm -rf /Library/Google/GoogleSoftwareUpdate/GoogleSoftwareUpdate.bundle
mv var var_back # var may not exist, but this is fine
ln -sh private/var var
chflags -h restricted /var
chflags -h hidden /var
xattr -sw com.apple.rootless “” /var
These Terminal commands will remove the affected version of Google Software Update and will restore the damaged portion of the file system. After that, a system reboot is needed. Users should perform these steps in Recovery Mode and root the credentials.
The good news here is that most users should not be affected by the bug as long as SIP is enabled, which is the default setting on the Mac.
1. After rebooting the affected system it would Kernel Panic. The system will reboot only to KP again.
2. User Logs out and the system shows the Setup Assistant.
3. The System Kernel Panics into a boot Loop.