bisecting fixing commit since 2d2791fce891fc20709232d49a6bae075b9a77f8 building syzkaller on 52e3731913ab2677be27c29ed8142b04e8f28521 testing commit 2d2791fce891fc20709232d49a6bae075b9a77f8 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: c25a0aa595c8c0b9a4fa8479dac848db5804bccf36be199a975fd0a46ec8080d all runs: crashed: INFO: task hung in nbd_ioctl testing current HEAD 46914f96189be290174e378c6bf9ccadfdb9ca1e testing commit 46914f96189be290174e378c6bf9ccadfdb9ca1e compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: c3d1aadb69165d1dbf5a92363d1aea005c73bb42723b75e3c5a83555dad459d1 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 31m10.715879948s (build: 20m31.755020028s, test: 10m5.182640255s) the crash still happens on HEAD commit msg: Linux 4.14.243 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: hci0 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout Bluetooth: hci0 command 0x0419 tx timeout