bisecting fixing commit since 1752938529c614a8ed4432ecce6ebc95d3b87207 building syzkaller on b1c228e1773559f05fa98950902ab025d6ab946e testing commit 1752938529c614a8ed4432ecce6ebc95d3b87207 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 4ec244e6b877a884da62ba182db519342ae3395553ab260db8f75963634a264a all runs: crashed: kernel BUG in ipgre_xmit testing current HEAD 66722c42ec916e92cadda46316f8f6e3fdcaedc6 testing commit 66722c42ec916e92cadda46316f8f6e3fdcaedc6 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 4c566470a292c2be8f4e0feea1d83961bc24d15056468be4e3231e133e6727ec all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 29m14.898300789s (build: 21m54.821689621s, test: 6m36.326787996s) the crash still happens on HEAD commit msg: Linux 4.14.256 crash: unregister_netdevice: waiting for DEV to become free Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci1 command 0x0409 tx timeout unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout