Hello, The cdc-acm driver (drivers/usb/class/cdc-acm.c) expects, when the control interface is different from the data interface, the following things: * one notification endpoint in control interface * two data endpoints (bulk/iso) in data interface The problem is that the first requirement is not in the spec as far as I understand it (it's optional). Furthermore, the driver doesn't check if there actually is an endpoint but makes a pointer from it: epctrl = &control_interface->cur_altsetting->endpoint[0].desc; If there is no notification endpoint, this will result in a NULL pointer dereference. Notice that there are two problems out there: * it should do the check anyway, for safety reason * it shouldn't assume an endpoint if the spec doesn't require it (but I'm unsure about this point) I submitted a bug report to the Kernel Bug Tracker (Bug 18322) but was then redirected to this mailing list for further discussion. Regards Amaury Pouly -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
