bisecting fixing commit since 2c8a3fceddf0dd87f278e7a5e01350f86f844b1c building syzkaller on fc9fd31ee7998c8b747752791000ea4eef07b5c6 testing commit 2c8a3fceddf0dd87f278e7a5e01350f86f844b1c compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 81f5f0c2677a4af22757718bd43d63cbd05f24811616cafc1126bf2b4ec7e19a all runs: crashed: BUG: looking up invalid subclass: NUM testing current HEAD 4ba8e26127c393c32776dff6d79c5b82de6dc542 testing commit 4ba8e26127c393c32776dff6d79c5b82de6dc542 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 6b0cf8d1652b303a0e1d845a63e97825ee73104a684c5e4d2e346ae8e74dac86 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 26m5.815278921s (build: 18m52.401943371s, test: 6m40.779132598s) the crash still happens on HEAD commit msg: Linux 4.14.262 crash: unregister_netdevice: waiting for DEV to become free Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout