bisecting fixing commit since 397a88b2cc869c823bf40bc403d36a62afec1edd building syzkaller on f89ed068375b8e31b9575a0ecc834c602657a9a9 testing commit 397a88b2cc869c823bf40bc403d36a62afec1edd compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 6be70e4630be020d7f612da48953ec0daeafc85a5dafe7c657da65b4ac09f605 run #0: crashed: SYZFAIL: netlink_send_ext: short netlink write run #1: crashed: SYZFAIL: netlink_send_ext: short netlink write run #2: crashed: SYZFAIL: netlink_send_ext: short netlink write run #3: crashed: SYZFAIL: netlink_send_ext: short netlink write run #4: crashed: SYZFAIL: netlink_send_ext: short netlink write run #5: crashed: SYZFAIL: netlink_send_ext: netlink read failed run #6: crashed: SYZFAIL: netlink_send_ext: short netlink write run #7: crashed: SYZFAIL: netlink_send_ext: netlink read failed run #8: crashed: SYZFAIL: netlink_send_ext: short netlink write run #9: crashed: SYZFAIL: netlink_send_ext: short netlink write run #10: crashed: SYZFAIL: netlink_send_ext: short netlink write run #11: crashed: SYZFAIL: netlink_send_ext: short netlink write run #12: crashed: SYZFAIL: netlink_send_ext: short netlink write run #13: crashed: SYZFAIL: netlink_send_ext: short netlink write run #14: crashed: SYZFAIL: netlink_send_ext: short netlink write run #15: crashed: SYZFAIL: netlink_send_ext: short netlink write run #16: crashed: SYZFAIL: netlink_send_ext: short netlink write run #17: crashed: SYZFAIL: netlink_send_ext: short netlink write run #18: crashed: SYZFAIL: netlink_send_ext: short netlink write run #19: crashed: SYZFAIL: netlink_send_ext: short netlink write testing current HEAD 66722c42ec916e92cadda46316f8f6e3fdcaedc6 testing commit 66722c42ec916e92cadda46316f8f6e3fdcaedc6 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 11682d3dd8f0af00347d395850d8d1856826ef30684373ef4d70525d7ac4a2b4 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 22m1.780149693s (build: 14m52.128703321s, test: 6m46.47689232s) the crash still happens on HEAD commit msg: Linux 4.14.256 crash: unregister_netdevice: waiting for DEV to become free Bluetooth: hci0 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: hci0 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout Bluetooth: hci1 command 0x0419 tx timeout