bisecting fixing commit since 7d7d1c0ab3eb7c8d8f63a126535018007823b207 building syzkaller on a343ba6b077a3efe7feb57783dcbb7496d2c3572 testing commit 7d7d1c0ab3eb7c8d8f63a126535018007823b207 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: adfe21951174b87a6228d1f372dbf9ca6d7dc1e2e9a9ab0c69a44184544c935a run #0: crashed: INFO: task hung in grab_super run #1: crashed: INFO: task hung in grab_super run #2: crashed: INFO: task hung in grab_super run #3: crashed: INFO: task hung in grab_super run #4: crashed: INFO: task hung in grab_super run #5: crashed: INFO: task hung in grab_super run #6: crashed: INFO: task hung in grab_super run #7: crashed: INFO: task hung in grab_super run #8: crashed: INFO: task hung in grab_super run #9: crashed: INFO: task hung in grab_super run #10: crashed: INFO: task hung in grab_super run #11: crashed: INFO: task hung in grab_super run #12: crashed: INFO: task hung in grab_super run #13: crashed: no output from test machine run #14: crashed: no output from test machine run #15: crashed: no output from test machine run #16: crashed: no output from test machine run #17: crashed: no output from test machine run #18: crashed: no output from test machine run #19: crashed: no output from test machine testing current HEAD 4ba8e26127c393c32776dff6d79c5b82de6dc542 testing commit 4ba8e26127c393c32776dff6d79c5b82de6dc542 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 4b1c59b6063e95ec494c801a272b633d1a6a9759784eabc5b1dc5501aa1af117 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 34m12.921151631s (build: 21m57.363014588s, test: 11m34.940350521s) the crash still happens on HEAD commit msg: Linux 4.14.262 crash: unregister_netdevice: waiting for DEV to become free unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci1 command 0x040f tx timeout unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout