bisecting fixing commit since cd529693461026636f76d0395a42cb2439bbd368 building syzkaller on 098b5d530648147c744a7c2eb8b78c1307f9d3ce testing commit cd529693461026636f76d0395a42cb2439bbd368 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: b3955bbf10595624b13d069a0289e931b73fa0df178deb79cd082abcf3d689a1 all runs: crashed: unregister_netdevice: waiting for DEV to become free testing current HEAD 66722c42ec916e92cadda46316f8f6e3fdcaedc6 testing commit 66722c42ec916e92cadda46316f8f6e3fdcaedc6 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 67c050cab64483cdfc058c71ff37af1cadb89c778128c93c0fbf1f434ca30d12 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 21m45.641601538s (build: 15m11.384136053s, test: 6m10.553712859s) the crash still happens on HEAD commit msg: Linux 4.14.256 crash: unregister_netdevice: waiting for DEV to become free Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci1 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: hci1 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout