bisecting fixing commit since cfb41ef9deb1e6572ac218ddfcec9567e5d1c101 building syzkaller on aba2b2fb3544d9e42991237c13d8cada421deda5 testing commit cfb41ef9deb1e6572ac218ddfcec9567e5d1c101 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 76621b6fbddae4cf32324411e8390597b34b61a5d5b23cb29456bc7d33fcc2a5 all runs: crashed: unregister_netdevice: waiting for DEV to become free testing current HEAD 964f3712e6a7447d9d3203f2be3f6c50e78ea179 testing commit 964f3712e6a7447d9d3203f2be3f6c50e78ea179 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 20bdfe511a80312eddbfe5ab95114e72ba343199e04d7c7be42a808b70e75940 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 27m25.781687123s (build: 20m20.575616424s, test: 6m27.95156072s) the crash still happens on HEAD commit msg: Linux 4.14.240 crash: unregister_netdevice: waiting for DEV to become free Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout