bisecting fixing commit since 670d6552eda8ff0c5f396d3d6f0174237917c66c building syzkaller on a8529b82fb3bb45832b08a099e7eb51707da9b37 testing commit 670d6552eda8ff0c5f396d3d6f0174237917c66c compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 959905dcd3fc25ce977cc926973329e935129189051e9b6a5a4fa9d51e85c9df all runs: crashed: KASAN: use-after-free Read in ip_tunnel_xmit testing current HEAD 964f3712e6a7447d9d3203f2be3f6c50e78ea179 testing commit 964f3712e6a7447d9d3203f2be3f6c50e78ea179 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: fab0bbfefcdc659331d939cc7921687c8e4aceec8586705ee50124bf484e3c2a all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 27m23.861586152s (build: 20m20.354304286s, test: 6m29.377856109s) the crash still happens on HEAD commit msg: Linux 4.14.240 crash: unregister_netdevice: waiting for DEV to become free unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout