bisecting fixing commit since 2d2791fce891fc20709232d49a6bae075b9a77f8 building syzkaller on a57db36fe48aa500618c2eac3b38c27afe6d290f testing commit 2d2791fce891fc20709232d49a6bae075b9a77f8 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 88aff3d455c84b73809072f09ed4b0b102f817e7436ed0e196bf8bd06caada97 all runs: crashed: KASAN: use-after-free Read in disk_unblock_events testing current HEAD 15a1c6b6f5162f7b70cf9a77cd8ed9771c1f0b53 testing commit 15a1c6b6f5162f7b70cf9a77cd8ed9771c1f0b53 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 4ad36bdfd59c92a81f36ae18216a09550115c41e71f376a50bfd6987670ff91c all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 32m16.980581259s (build: 24m28.785964793s, test: 6m1.503363457s) the crash still happens on HEAD commit msg: Linux 4.14.276 crash: unregister_netdevice: waiting for DEV to become free unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci1 command 0x0409 tx timeout 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 Bluetooth: hci0 command 0x041b tx timeout 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: 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: hci0 command 0x0419 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 unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1