On Wed, 2013-11-06 at 16:38 +0100, Jiri Kosina wrote:

On Tue, 29 Oct 2013, Luis Henriques wrote:

quoted

James has reported a NULL pointer dereference[1] on the appleir
driver.  From the bug report[2] it looks like it is 100%
reproducible using a 3.12-rc6 kernel simply by pressing any button on
the IR remote.

quoted

From the stack trace, it looks like input_event is invoked with the

input_dev parameter set to NULL, which seems to indicate that
appleir_input_configured is never invoked.

Any ideas?

[1] https://launchpadlibrarian.net/154942024/macmini-oops.jpg
[2] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1244505

[ adding some more CCs ]

Okay, so apparently we didn't register with input, but only hiddev / 
hidraw.

appleir 0003:05AC:8240.0005: hiddev0,hidraw4: USB HID v1.11 Device [Apple Computer, Inc. IR Receiver] on usb-0000:00:1d.3-2/input0

Therefore ->input_configured() callback has never been called, and thus we 
oops due to appleir->input_dev being NULL when the first raw event is 
reported.

Could you please provide report descriptor of the device?

The driver apparently relies on it being registered with hid-input, but 
for some reason that doesn't happen.

FWIW, my original patch (and driver) was an input driver, not a hid one.
I'm not sure either how the new driver got tested.