bisecting fixing commit since 5b7a52cd2eef952cee8a72512ef370bcdef46636 building syzkaller on a1839e81524f4e427a4b57bca0e4633d459d3d18 testing commit 5b7a52cd2eef952cee8a72512ef370bcdef46636 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: eed80c68945b869114dda845c8c72a72dfcf4fc1fd49bacfbc4d4097f0ec0ae3 all runs: crashed: KASAN: use-after-free Read in kvm_vm_ioctl_unregister_coalesced_mmio testing current HEAD 162b95d01320370b80cb2d5724cea4ae538ac740 testing commit 162b95d01320370b80cb2d5724cea4ae538ac740 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 9188ecc778dbd24ac6ae37e86cdf654de164ea74c2d7381d0c4f7825a82660c2 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 29m31.251910963s (build: 22m24.64385289s, test: 6m16.873307105s) the crash still happens on HEAD commit msg: Linux 4.14.244 crash: unregister_netdevice: waiting for DEV to become free Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci0 command 0x0419 tx timeout