bisecting fixing commit since 7d7d1c0ab3eb7c8d8f63a126535018007823b207 building syzkaller on a343ba6b077a3efe7feb57783dcbb7496d2c3572 testing commit 7d7d1c0ab3eb7c8d8f63a126535018007823b207 with gcc (GCC) 8.4.1 20210217 kernel signature: 86b624f56d0e2aaf1fcc88ad937ddc5eccd7f3225b3aef836b04b5ea794cc088 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: INFO: task hung in grab_super run #14: crashed: INFO: task hung in grab_super 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 4e68c9b0763ff55eaa69d6e519f07515f1c9037b testing commit 4e68c9b0763ff55eaa69d6e519f07515f1c9037b with gcc (GCC) 8.4.1 20210217 kernel signature: 6b96c8449bbe5b9081fb5f1aaab8c6bf1407b3e028edaf69b4f180ed688c6791 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 28m19.553805185s (build: 16m26.773031681s, test: 11m32.916190537s) the crash still happens on HEAD commit msg: Linux 4.14.239 crash: unregister_netdevice: waiting for DEV to become free can: request_module (can-proto-0) failed. can: request_module (can-proto-0) failed. unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout