bisecting fixing commit since 7d7d1c0ab3eb7c8d8f63a126535018007823b207 building syzkaller on f54a5c0916af7d798b204eb70c484f154d69e0a3 testing commit 7d7d1c0ab3eb7c8d8f63a126535018007823b207 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 88db4c9722609554fec9c7521048142f03ca13ec8d2aabbee995bd1f02fe6232 all runs: crashed: WARNING: ODEBUG bug in pppol2tp_release testing current HEAD 569d1abf9402e943bf00821a6e0b8e13bffde699 testing commit 569d1abf9402e943bf00821a6e0b8e13bffde699 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 2be0fb538915cba07c19e79d00691e1e9ec559e62710c9a397d6b64d402c3894 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 24m8.576121536s (build: 16m31.539197086s, test: 7m6.08372976s) the crash still happens on HEAD commit msg: Linux 4.14.278 crash: unregister_netdevice: waiting for DEV to become free Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci0 command 0x0409 tx timeout unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci2 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: hci2 command 0x040f tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout