bisecting fixing commit since 670d6552eda8ff0c5f396d3d6f0174237917c66c building syzkaller on a8529b82fb3bb45832b08a099e7eb51707da9b37 testing commit 670d6552eda8ff0c5f396d3d6f0174237917c66c compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 21a39f2e642b0d8b45d8838c487b9aca95f46ef2d096540b8579c5f0edc4ca36 all runs: crashed: KASAN: use-after-free Read in ip_tunnel_xmit testing current HEAD fa33f9094f36943ea32f7fbe323293b62e96151d testing commit fa33f9094f36943ea32f7fbe323293b62e96151d compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: fee8c6e94496287ab6373ef1943c8ffad677dc5a825aa618b43c6a898dfda1af all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 24m53.789046411s (build: 18m6.629960626s, test: 6m19.890758589s) the crash still happens on HEAD commit msg: Linux 4.14.268 crash: unregister_netdevice: waiting for DEV to become free unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci3 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: hci3 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci0 command 0x0419 tx timeout