bisecting fixing commit since 2d2791fce891fc20709232d49a6bae075b9a77f8 building syzkaller on 52e3731913ab2677be27c29ed8142b04e8f28521 testing commit 2d2791fce891fc20709232d49a6bae075b9a77f8 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 2681f6507a0a33b7fed6c9a3c309972442161764c95f98d72d0eb110ec504350 all runs: crashed: INFO: task hung in nbd_ioctl testing current HEAD ed99bf0e81b558df39f7db2fa96d0228be4198c6 testing commit ed99bf0e81b558df39f7db2fa96d0228be4198c6 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 14ebc4334d8611aba2b1c451d10d5fe1297171c5702a9a4ce26029a7b1aaf111 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 32m52.920684599s (build: 21m20.506015316s, test: 10m42.197500185s) the crash still happens on HEAD commit msg: Linux 4.14.250 crash: unregister_netdevice: waiting for DEV to become free Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout