bisecting fixing commit since 7d7d1c0ab3eb7c8d8f63a126535018007823b207 building syzkaller on f54a5c0916af7d798b204eb70c484f154d69e0a3 testing commit 7d7d1c0ab3eb7c8d8f63a126535018007823b207 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 5847c2a7dc123efe2e0633986a5d037baac0247fc9664ea74a5a76824be5068f all runs: crashed: WARNING: suspicious RCU usage in tcp_disconnect testing current HEAD 162b95d01320370b80cb2d5724cea4ae538ac740 testing commit 162b95d01320370b80cb2d5724cea4ae538ac740 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: d6172a9bfaae2393eac9cf00d41f52a3975e014f55899a6434b271b40db58c89 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 27m49.329046454s (build: 21m4.618744519s, test: 6m11.268382345s) the crash still happens on HEAD commit msg: Linux 4.14.244 crash: unregister_netdevice: waiting for DEV to become free Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci5 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: hci3 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout