Hello, > > Hmm, I see quite a few drivers assuming that endpoint 0 will be present. > > I wonder if that should not be solved at USB level. > > Every USB device always has endpoint 0. If one didn't, the kernel > wouldn't be able to initialize and enumerate it. Yes for the normal USB device. This case is a weird USB device (with no endpoints) specially designed to be weird. My point here is that even a weird device probing should not crash a kernel by a NULL-deref. > > Alan, does it make sense to have drivers probe interface if it does not > > have any endpoints? > > Yes; in theory an interface can do everything it needs using only > endpoint 0. Driver shouldn't assume anything about the endpoints in > the interfaces they problem. The current kernel code in drivers/usb/core/config.c accepts an interface with no endpoints in one of its configurations, and I could not find a direct ban for that in USB standard. So, I currently believe, it is a driver job to check if the endpoint 0 exist, otherwise we must change the kernel USB detection code. btw, indeed, this is not the only driver with this problem, I've met 2 more. Best regards, Vladis Dronov | Red Hat, Inc. | Product Security Engineer -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
