bisecting fixing commit since 7d7d1c0ab3eb7c8d8f63a126535018007823b207 building syzkaller on f54a5c0916af7d798b204eb70c484f154d69e0a3 testing commit 7d7d1c0ab3eb7c8d8f63a126535018007823b207 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: ca1b40918c03c522de0258284880bb0ba307f49a4dfdec5957315b8cd2f29b0f all runs: crashed: WARNING: suspicious RCU usage in tcp_disconnect testing current HEAD 424a46ea058e160ae6fdd0693092ba79da533f26 testing commit 424a46ea058e160ae6fdd0693092ba79da533f26 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 2016440939dd8e25f39b831e669c1e5d5718621765173bcafea1fee1aecdac08 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 26m29.336197474s (build: 19m33.045368003s, test: 6m30.596128444s) the crash still happens on HEAD commit msg: Linux 4.14.288 crash: unregister_netdevice: waiting for DEV to become free Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout