bisecting fixing commit since 670d6552eda8ff0c5f396d3d6f0174237917c66c building syzkaller on a8529b82fb3bb45832b08a099e7eb51707da9b37 testing commit 670d6552eda8ff0c5f396d3d6f0174237917c66c compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: fc34a53ee8676477a0271739baa94eb508c695811aaae9bf2ccc2fe5e0a16a82 all runs: crashed: KASAN: use-after-free Read in ip_tunnel_xmit testing current HEAD 4ba8e26127c393c32776dff6d79c5b82de6dc542 testing commit 4ba8e26127c393c32776dff6d79c5b82de6dc542 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: aecd1e6d1b82cbfa7a72b5dafed30e4473cc7ba3b69123211fabb18c0347ef7b all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 21m52.726929328s (build: 15m0.268195949s, test: 6m28.819774138s) the crash still happens on HEAD commit msg: Linux 4.14.262 crash: unregister_netdevice: waiting for DEV to become free Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci3 command 0x0409 tx timeout unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout