bisecting fixing commit since 6b6446efedb27c2766745a04f9b5d4449f51391d building syzkaller on cba33199be220cbf61f7c0c8223d88a25a913d6f testing commit 6b6446efedb27c2766745a04f9b5d4449f51391d compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: d016c2ee0a5336f933bbfd23cdda45eff6ac532f51d6771ab1e2dd033df5fc07 all runs: crashed: INFO: task hung in rtnl_lock testing current HEAD 9dfbac0e6b8600043de8dc85ed072f5f1342dc15 testing commit 9dfbac0e6b8600043de8dc85ed072f5f1342dc15 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 32990e6c5da3a0f5339df2cf9b8d9a7c8f0a0e7978156ffe32f1eea1d11ac2e3 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 26m56.063460831s (build: 14m53.389404605s, test: 10m23.258751038s) the crash still happens on HEAD commit msg: Linux 4.14.258 crash: unregister_netdevice: waiting for DEV to become free Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci1 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: hci1 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout