Hi Greg, >> Hi Mathias, >> >> i got a NULL pointer deref in the usbfs and analyzed it. >> The connected device seemed to have trouble on USB transmissions. >> However, I have the impression that there is a race between finishing URB handling and disconnection of devices. >> In detail: >> [ 4979.029666] xhci_hcd 0000:00:15.0: USB transfer error. Maybe the USB cable is bad? > > Did your cable die? > > And 4.14 is quite old, what about 5.13? > > thanks, > > greg k-h That was reported from a device in the field. Yes, a defective cable is bad, but shouldn't the kernel's health avoid a NULL pointer deref? 4.14 is used due to being LTS and the device firmware has been stabilized on that. We frequently update on the 4.14 and monitor patches, but there's nothing regarding an xhci race up to now in 4.14 seen, I checked that. Not sure if this would happen on a newer kernel also, but we can't test that on the device in the field. It was seen once so far, but the indication of a race is really high here. If nobody of the USB maintainers has an idea, I'll fix that with my proposal. Best regards Carsten ----------------- Siemens Electronic Design Automation GmbH; Anschrift: Arnulfstraße 201, 80634 München; Gesellschaft mit beschränkter Haftung; Geschäftsführer: Thomas Heurung, Frank Thürauf; Sitz der Gesellschaft: München; Registergericht München, HRB 106955
