bisecting fixing commit since f96eb53cbd76415edfba99c2cfa88567a885a428 building syzkaller on d236a457274375e5273ac4e958722659929c469f testing commit f96eb53cbd76415edfba99c2cfa88567a885a428 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: b0c0e476096bc43c4fda10e40babb3fdcca8b3ac9438357a08c90c7f53d7696b all runs: crashed: unregister_netdevice: waiting for DEV to become free testing current HEAD f11944f1aa1cda3fd8b4edc71e3cf9dceb40234f testing commit f11944f1aa1cda3fd8b4edc71e3cf9dceb40234f compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 6ee606b64e939a848c64e0dae3723ba9988f0501772fca33ed10c45d2450a522 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 29m55.906753346s (build: 22m45.082289324s, test: 6m31.738996867s) the crash still happens on HEAD commit msg: Linux 4.14.248 crash: unregister_netdevice: waiting for DEV to become free unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout