bisecting fixing commit since 2d2791fce891fc20709232d49a6bae075b9a77f8 building syzkaller on 52e3731913ab2677be27c29ed8142b04e8f28521 testing commit 2d2791fce891fc20709232d49a6bae075b9a77f8 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 335a37a0836ca3ed8f1cb2158dc1d152895611a67123c31b880e44e309cb8d7d all runs: crashed: INFO: task hung in nbd_ioctl testing current HEAD bfdef05c8da46b022172695aa493cff7ac667a4b testing commit bfdef05c8da46b022172695aa493cff7ac667a4b compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: bb2a032b466169a2ec87bed3383fb37a95fc2a907b31cfab4997d2c07f87fd19 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 25m19.853337434s (build: 14m34.576035417s, test: 10m14.619553496s) the crash still happens on HEAD commit msg: Linux 4.14.261 crash: unregister_netdevice: waiting for DEV to become free Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci1 command 0x0409 tx timeout unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout