bisecting fixing commit since 2c8a3fceddf0dd87f278e7a5e01350f86f844b1c building syzkaller on fc9fd31ee7998c8b747752791000ea4eef07b5c6 testing commit 2c8a3fceddf0dd87f278e7a5e01350f86f844b1c with gcc (GCC) 8.4.1 20210217 kernel signature: 9f5827330dfbd32b2c6bdab7044d7d0ff23117a098df88d1606294cce149eda2 all runs: crashed: BUG: looking up invalid subclass: 8 testing current HEAD ad8397a84e1e425e3f8221638cee2bfa237d9b2c testing commit ad8397a84e1e425e3f8221638cee2bfa237d9b2c with gcc (GCC) 8.4.1 20210217 kernel signature: 7b6fd3b35d619d3fb2e045eb8d6b99a579341473dfd543c68fe5303b70ab8076 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 25m48.126606947s (build: 18m45.941393577s, test: 6m30.369629694s) the crash still happens on HEAD commit msg: Linux 4.14.234 crash: unregister_netdevice: waiting for DEV to become free Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout