bisecting fixing commit since 670d6552eda8ff0c5f396d3d6f0174237917c66c building syzkaller on a8529b82fb3bb45832b08a099e7eb51707da9b37 testing commit 670d6552eda8ff0c5f396d3d6f0174237917c66c compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 07bd679b3af31a450a8e816b853f71062191a3d1d930bef78d5d909766147641 all runs: crashed: KASAN: use-after-free Read in ip_tunnel_xmit testing current HEAD cd529693461026636f76d0395a42cb2439bbd368 testing commit cd529693461026636f76d0395a42cb2439bbd368 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 593df56c54c8d072a8dfa3ddec59b6518355c17dbee9e3d24ed2cc4f740d925a all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 22m7.879494856s (build: 15m4.894993175s, test: 6m39.909749721s) the crash still happens on HEAD commit msg: Linux 4.14.253 crash: unregister_netdevice: waiting for DEV to become free Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci3 command 0x0409 tx timeout unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 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: hci1 command 0x041b tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci1 command 0x040f 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: hci3 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout