Bluetooth device-related kernel panics

[Published Wednesday, May 23rd]

Kernel panics are often associated with both Apple-provided and third-party hardware that make use of kernel extensions (items with the file extension .kext located in /System/Library/Extensions), and one such grouping of devices implicated in a rash of recently reported kernel panics is Bluetooth.

Determining whether or not a Bluetooth device is potentially behind any given kernel panic is usually as easy as inspecting the appropriate crash report (as described in our tutorial "An introduction to reading Mac OS X crash reports") and looking for one or more of the following lines in the Backtrace:

• com.apple.driver.IOBluetoothHIDDriver
• com.apple.iokit.IOBluetoothFamily
• com.apple.iokit.IOHIDFamily

These lines refer to various Bluetooth-related kernel extensions located in /System/Library/Extensions, such as:

• IOBluetoothFamily.kext
• IOBluetoothHIDDriver.kext
• IOHIDFamily.kext

Once you've identified a Bluetooth device(s) as the potential cuplrit in a kernel panic, there are a few options for dealing with the problem:

Disconnect and test Simply disconnecting all paired Bluetooth devices then reconnecting them in sets (one or more at a time) and checking for persistence of the kernel panics can reveal on or more culpable devices. You can then look for updated drivers or firmware (outdated firmware is a key factor in many kernel panics) for the offending device or discard it permanently.

Clear kernel extension-related caches Use a tool like Cocktail or Tiger Cache Cleaner, or manually delete the following files:

• com.apple.kernelcaches (a folder in /System/Library/Caches)
• Extensions.kextcache (a file in /System/Library)
• Extensions.mkext (a file in /System/Library/)

Have you recently had an experience with an apparently Bluetooth-related kernel panic? Please drop us a line.

Resources