bisecting fixing commit since 2d2791fce891fc20709232d49a6bae075b9a77f8
building syzkaller on 52e3731913ab2677be27c29ed8142b04e8f28521
testing commit 2d2791fce891fc20709232d49a6bae075b9a77f8 with gcc (GCC) 8.4.1 20210217
kernel signature: 7dc63643c702b94b33993cb07720c8427ac8a42f7d39a8f4161f71ba6ce65aa5
all runs: crashed: INFO: task hung in nbd_ioctl
testing current HEAD 3d3abdc8ebd3c3082e4398fc73ceb4c852b66e85
testing commit 3d3abdc8ebd3c3082e4398fc73ceb4c852b66e85 with gcc (GCC) 8.4.1 20210217
kernel signature: b5b1d5c9b9948c423077ea73c237937e050253280cb936d40297e5a571cd4bad
all runs: crashed: unregister_netdevice: waiting for DEV to become free
revisions tested: 2, total time: 25m20.114506218s (build: 14m54.576347635s, test: 10m4.807435956s)
the crash still happens on HEAD
commit msg: Linux 4.14.236
crash: unregister_netdevice: waiting for DEV to become free
unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1
Bluetooth: hci4 command 0x0409 tx timeout
Bluetooth: hci5 command 0x0409 tx timeout
Bluetooth: hci2 command 0x0409 tx timeout
Bluetooth: hci1 command 0x0409 tx timeout
Bluetooth: hci0 command 0x0409 tx timeout
Bluetooth: hci3 command 0x0409 tx timeout
Bluetooth: hci5 command 0x041b tx timeout
Bluetooth: hci3 command 0x041b tx timeout
Bluetooth: hci4 command 0x041b tx timeout
Bluetooth: hci0 command 0x041b tx timeout
Bluetooth: hci1 command 0x041b tx timeout
Bluetooth: hci2 command 0x041b tx timeout
Bluetooth: hci3 command 0x040f tx timeout
Bluetooth: hci2 command 0x040f tx timeout
Bluetooth: hci5 command 0x040f tx timeout
Bluetooth: hci1 command 0x040f tx timeout
Bluetooth: hci0 command 0x040f tx timeout
Bluetooth: hci4 command 0x040f tx timeout
Bluetooth: hci2 command 0x0419 tx timeout
Bluetooth: hci4 command 0x0419 tx timeout
Bluetooth: hci0 command 0x0419 tx timeout
Bluetooth: hci3 command 0x0419 tx timeout
Bluetooth: hci1 command 0x0419 tx timeout
Bluetooth: hci5 command 0x0419 tx timeout