bisecting fixing commit since a35d65bedfbc38cffe2701798cd6810bbdf07892 building syzkaller on 3cd800e43d452c348a66ba475143831d94969a24 testing commit a35d65bedfbc38cffe2701798cd6810bbdf07892 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 1f2292dc7a079fbbc02666bb78613d7ea7b507340ca688ae266c6135817ac28a all runs: crashed: unregister_netdevice: waiting for DEV to become free testing current HEAD 74766a973637a02c32c04c1c6496e114e4855239 testing commit 74766a973637a02c32c04c1c6496e114e4855239 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: f9c73716cd4afed627f08e1efb7fb16d1f04bcc429558edc3ed9349359e42dea all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 20m52.122567537s (build: 14m42.871872022s, test: 5m48.721687262s) the crash still happens on HEAD commit msg: Linux 4.14.275 crash: unregister_netdevice: waiting for DEV to become free unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout Bluetooth: hci1 command 0x0419 tx timeout