bisecting fixing commit since 2d2791fce891fc20709232d49a6bae075b9a77f8
building syzkaller on 52e3731913ab2677be27c29ed8142b04e8f28521
testing commit 2d2791fce891fc20709232d49a6bae075b9a77f8 with gcc (GCC) 8.4.1 20210217
kernel signature: 1c72b0a7193ac04fd68cfdb38c401684fca5bb1fa633a17d74a9a7171904085e
all runs: crashed: INFO: task hung in nbd_ioctl
testing current HEAD 4e68c9b0763ff55eaa69d6e519f07515f1c9037b
testing commit 4e68c9b0763ff55eaa69d6e519f07515f1c9037b with gcc (GCC) 8.4.1 20210217
kernel signature: 7cac49b2dc8dd3451b10bc202be90655c64f92921d6b9795bb9dd4edb0eb637c
all runs: crashed: unregister_netdevice: waiting for DEV to become free
revisions tested: 2, total time: 25m35.900836017s (build: 15m2.420661921s, test: 10m11.758996469s)
the crash still happens on HEAD
commit msg: Linux 4.14.239
crash: unregister_netdevice: waiting for DEV to become free
Bluetooth: hci0 command 0x0409 tx timeout
Bluetooth: hci2 command 0x0409 tx timeout
Bluetooth: hci1 command 0x0409 tx timeout
unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1
Bluetooth: hci5 command 0x0409 tx timeout
Bluetooth: hci3 command 0x0409 tx timeout
Bluetooth: hci4 command 0x0409 tx timeout
Bluetooth: hci1 command 0x041b tx timeout
Bluetooth: hci2 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: hci0 command 0x040f tx timeout
Bluetooth: hci2 command 0x040f tx timeout
Bluetooth: hci1 command 0x040f tx timeout
Bluetooth: hci5 command 0x040f tx timeout
Bluetooth: hci3 command 0x040f tx timeout
Bluetooth: hci4 command 0x040f tx timeout
Bluetooth: hci1 command 0x0419 tx timeout
Bluetooth: hci2 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