bisecting fixing commit since 397a88b2cc869c823bf40bc403d36a62afec1edd building syzkaller on f89ed068375b8e31b9575a0ecc834c602657a9a9 testing commit 397a88b2cc869c823bf40bc403d36a62afec1edd with gcc (GCC) 8.4.1 20210217 kernel signature: 718d78d9bdde4dea82c400badbeb11847b3e9707228b18c7cea7766256b206eb run #0: crashed: SYZFAIL: netlink_send_ext: netlink read failed run #1: crashed: SYZFAIL: netlink_send_ext: netlink read failed run #2: crashed: SYZFAIL: netlink_send_ext: netlink read failed run #3: crashed: SYZFAIL: netlink_send_ext: netlink read failed run #4: crashed: SYZFAIL: netlink_send_ext: netlink read failed run #5: crashed: SYZFAIL: netlink_send_ext: netlink read failed run #6: crashed: SYZFAIL: netlink_send_ext: netlink read failed run #7: crashed: SYZFAIL: netlink_send_ext: netlink read failed run #8: crashed: SYZFAIL: netlink_send_ext: netlink read failed run #9: crashed: SYZFAIL: netlink_send_ext: netlink read failed run #10: crashed: SYZFAIL: netlink_send_ext: netlink read failed run #11: crashed: SYZFAIL: netlink_send_ext: short netlink write run #12: crashed: SYZFAIL: netlink_send_ext: netlink read failed run #13: crashed: SYZFAIL: netlink_send_ext: netlink read failed run #14: crashed: SYZFAIL: netlink_send_ext: netlink read failed run #15: crashed: SYZFAIL: netlink_send_ext: netlink read failed run #16: crashed: SYZFAIL: netlink_send_ext: netlink read failed run #17: crashed: SYZFAIL: netlink_send_ext: netlink read failed run #18: crashed: SYZFAIL: netlink_send_ext: netlink read failed run #19: crashed: SYZFAIL: netlink_send_ext: netlink read failed testing current HEAD 4e68c9b0763ff55eaa69d6e519f07515f1c9037b testing commit 4e68c9b0763ff55eaa69d6e519f07515f1c9037b with gcc (GCC) 8.4.1 20210217 kernel signature: ce6d310023bf9549a794faf2eb17b7ad5fcc96f7c91ddc066e37ab8895e09907 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 25m2.09109344s (build: 17m52.8872957s, test: 6m37.375356282s) the crash still happens on HEAD commit msg: Linux 4.14.239 crash: unregister_netdevice: waiting for DEV to become free Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci0 command 0x0419 tx timeout