bisecting fixing commit since 6b6446efedb27c2766745a04f9b5d4449f51391d building syzkaller on cba33199be220cbf61f7c0c8223d88a25a913d6f testing commit 6b6446efedb27c2766745a04f9b5d4449f51391d compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 5f5df8cb11ffe52d0502fa47e77423ecfacc3bc5fd24211d07366c3cdb150b8e run #0: crashed: possible deadlock in __get_super run #1: crashed: possible deadlock in __get_super run #2: crashed: possible deadlock in __get_super run #3: crashed: possible deadlock in blkdev_put run #4: crashed: possible deadlock in blkdev_put run #5: crashed: possible deadlock in __get_super run #6: crashed: possible deadlock in __get_super run #7: crashed: possible deadlock in __get_super run #8: crashed: possible deadlock in __get_super run #9: crashed: possible deadlock in __get_super run #10: crashed: possible deadlock in blkdev_put run #11: crashed: possible deadlock in __get_super run #12: crashed: possible deadlock in __get_super run #13: crashed: INFO: task hung in blkdev_put run #14: crashed: INFO: task hung in blkdev_put run #15: crashed: INFO: task hung in blkdev_put run #16: crashed: INFO: task hung in blkdev_put run #17: crashed: INFO: task hung in blkdev_put run #18: crashed: INFO: task hung in __blkdev_get run #19: crashed: INFO: task hung in blkdev_put testing current HEAD f96eb53cbd76415edfba99c2cfa88567a885a428 testing commit f96eb53cbd76415edfba99c2cfa88567a885a428 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 521ea23ff8ed8fec936a41742d46da109ba6f69205558e88836d06a4737a7d47 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 25m16.562380226s (build: 14m23.614542143s, test: 10m28.034690336s) the crash still happens on HEAD commit msg: Linux 4.14.246 crash: unregister_netdevice: waiting for DEV to become free Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci1 command 0x0409 tx timeout unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci5 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: hci5 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout