bisecting fixing commit since 964f3712e6a7447d9d3203f2be3f6c50e78ea179 building syzkaller on fd5118098a3df4301eba91aeca37119ccb209403 testing commit 964f3712e6a7447d9d3203f2be3f6c50e78ea179 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 68c5382f4b7490da22ee846c2a208c02696b8c2f75bf6e39422d650f10d87b42 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: 03956cd6bb023e32c821a9a1922968cdb0e0f64e8b448539dd1343bd19e98d18 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 24m44.885636833s (build: 17m53.352034714s, test: 6m19.570429607s) the crash still happens on HEAD commit msg: Linux 4.14.256 crash: unregister_netdevice: waiting for DEV to become free unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci3 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: hci3 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout