bisecting fixing commit since 670d6552eda8ff0c5f396d3d6f0174237917c66c building syzkaller on a8529b82fb3bb45832b08a099e7eb51707da9b37 testing commit 670d6552eda8ff0c5f396d3d6f0174237917c66c compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 8a77a8ea07ad9652ca02c52fb5886ee2f6f49f2d0d5ff592a1e3d928ba2be3a8 all runs: crashed: KASAN: use-after-free Read in ip_tunnel_xmit testing current HEAD 35c4ba160ab6133e548468bd0bd1109990dc7736 testing commit 35c4ba160ab6133e548468bd0bd1109990dc7736 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: b6951baa7576927c7e1446d586024054341bcc65de2c6e3e10f145f76c78fd58 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 24m42.661805256s (build: 17m57.596130353s, test: 6m20.379213125s) the crash still happens on HEAD commit msg: Linux 4.14.245 crash: unregister_netdevice: waiting for DEV to become free can: request_module (can-proto-0) failed. can: request_module (can-proto-0) failed. Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci0 command 0x0409 tx timeout unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 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: hci0 command 0x041b 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: 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: hci2 command 0x040f tx timeout Bluetooth: hci0 command 0x0419 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