bisecting fixing commit since cd529693461026636f76d0395a42cb2439bbd368 building syzkaller on be531bb42381b245eed805e49fd889d1c2118c76 testing commit cd529693461026636f76d0395a42cb2439bbd368 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: d0680b09221feb6a71a849346b52964bf544872c64fe4ff521548fc19399f7c0 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: 28625d8748489853180dd5ddd337e90f4ae907f427791500b050c0a5ba05b922 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 23m13.886425926s (build: 16m24.98453795s, test: 6m20.752253259s) the crash still happens on HEAD commit msg: Linux 4.14.256 crash: unregister_netdevice: waiting for DEV to become free Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci3 command 0x0409 tx timeout unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout