bisecting fixing commit since 397a88b2cc869c823bf40bc403d36a62afec1edd building syzkaller on f89ed068375b8e31b9575a0ecc834c602657a9a9 testing commit 397a88b2cc869c823bf40bc403d36a62afec1edd with gcc (GCC) 8.4.1 20210217 kernel signature: bb205fb45271fee85fe279c62c66997de402ac9a6baead34420f74791188fffc all runs: crashed: SYZFAIL: netlink_send_ext: netlink read failed testing current HEAD cfb41ef9deb1e6572ac218ddfcec9567e5d1c101 testing commit cfb41ef9deb1e6572ac218ddfcec9567e5d1c101 with gcc (GCC) 8.4.1 20210217 kernel signature: 0d568f05165542ca887288fafb5710f9c1758051a2e159ceb15ee25dac1b80a6 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 21m19.244333404s (build: 14m41.11250134s, test: 6m10.894612845s) the crash still happens on HEAD commit msg: Linux 4.14.237 crash: unregister_netdevice: waiting for DEV to become free unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci1 command 0x0419 tx timeout