bisecting fixing commit since 7d7d1c0ab3eb7c8d8f63a126535018007823b207 building syzkaller on f54a5c0916af7d798b204eb70c484f154d69e0a3 testing commit 7d7d1c0ab3eb7c8d8f63a126535018007823b207 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 32ef6ba8f0441c5673d2c00bb27678b2a3cae089d1d775ad498d8253f04b41da all runs: crashed: WARNING: suspicious RCU usage in tcp_disconnect testing current HEAD 9dfbac0e6b8600043de8dc85ed072f5f1342dc15 testing commit 9dfbac0e6b8600043de8dc85ed072f5f1342dc15 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 3d409ec498ed0d7cddb01a9b2a6da434f919fa89d3430c1286c5bff7b8168e1f all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 22m5.013996s (build: 14m52.889425208s, test: 6m45.350200445s) the crash still happens on HEAD commit msg: Linux 4.14.258 crash: unregister_netdevice: waiting for DEV to become free Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 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: hci3 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci4 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: hci3 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout