bisecting fixing commit since 6b6446efedb27c2766745a04f9b5d4449f51391d building syzkaller on cba33199be220cbf61f7c0c8223d88a25a913d6f testing commit 6b6446efedb27c2766745a04f9b5d4449f51391d compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 59bc51a9bc7c645b1e3186209bf129b44e0dff94b07e714771eb637708b174c4 all runs: crashed: INFO: task hung in rtnl_lock testing current HEAD 74766a973637a02c32c04c1c6496e114e4855239 testing commit 74766a973637a02c32c04c1c6496e114e4855239 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: e43d2a0612ffcad63169912b1de24a7bd8294f23bac625cb51052fe367353df6 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 34m2.531487896s (build: 23m41.477828799s, test: 9m49.081817409s) the crash still happens on HEAD commit msg: Linux 4.14.275 crash: unregister_netdevice: waiting for DEV to become free Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci3 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: hci0 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout