bisecting fixing commit since 7d7d1c0ab3eb7c8d8f63a126535018007823b207 building syzkaller on ed7d41c582d6f194ff35353d8bfdf7681dc0718e testing commit 7d7d1c0ab3eb7c8d8f63a126535018007823b207 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: d3311c12ab406924e727e8f57f5ae9dfd40b6081be185f88de5032557a900d11 run #0: crashed: INFO: task hung in blkdev_reread_part run #1: crashed: INFO: task hung in lo_open run #2: crashed: INFO: task hung in lo_open run #3: crashed: INFO: task hung in lo_open run #4: crashed: INFO: task hung in lo_open run #5: crashed: INFO: task hung in lo_open run #6: crashed: INFO: task hung in lo_open run #7: crashed: INFO: task hung in loop_control_ioctl run #8: crashed: INFO: task hung in lo_open run #9: crashed: INFO: task hung in lo_release run #10: crashed: INFO: task hung in lo_open run #11: crashed: INFO: task hung in blkdev_reread_part run #12: crashed: INFO: task hung in __blkdev_get run #13: crashed: INFO: task hung in lo_open run #14: crashed: INFO: task hung in lo_open run #15: crashed: INFO: task hung in lo_open run #16: crashed: INFO: task hung in lo_open run #17: crashed: INFO: task hung in lo_open run #18: crashed: INFO: task hung in lo_open run #19: crashed: INFO: task hung in lo_open testing current HEAD bfdef05c8da46b022172695aa493cff7ac667a4b testing commit bfdef05c8da46b022172695aa493cff7ac667a4b compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 38decffc5c56ffa1a9f3bc33c9c884da94b39884df71d48c583f6bea7b2d698b all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 28m52.173085129s (build: 17m51.059923424s, test: 10m38.82402007s) the crash still happens on HEAD commit msg: Linux 4.14.261 crash: unregister_netdevice: waiting for DEV to become free unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci3 command 0x041b tx timeout 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: hci4 command 0x041b tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci3 command 0x0419 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: hci4 command 0x0419 tx timeout