bisecting fixing commit since cfb41ef9deb1e6572ac218ddfcec9567e5d1c101 building syzkaller on 9d2ab5dfe7727dfea4b9b279f4edf731acb386ef testing commit cfb41ef9deb1e6572ac218ddfcec9567e5d1c101 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 1e25710d2df6591d9e93ba3e1c6c488f6dfbc9d9e4dbb6420b38e5cbf5e2da3d all runs: crashed: unregister_netdevice: waiting for DEV to become free testing current HEAD 8ea4f73cfa7e0555dc03aedde52db54a6587ab43 testing commit 8ea4f73cfa7e0555dc03aedde52db54a6587ab43 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: e7d979bafd91366f6879be58bca25d114aa4ab85cca34a62841d6c1f1ef12376 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 26m25.729236655s (build: 19m46.019962782s, test: 6m14.291320634s) the crash still happens on HEAD commit msg: Linux 4.14.247 crash: unregister_netdevice: waiting for DEV to become free unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout