bisecting fixing commit since 2c8a3fceddf0dd87f278e7a5e01350f86f844b1c building syzkaller on 14052202e8d8d0bb407512b6861e9085f9171241 testing commit 2c8a3fceddf0dd87f278e7a5e01350f86f844b1c with gcc (GCC) 8.4.1 20210217 kernel signature: f04aa09768582560fa52007a2965d8f83860e259218105b2be46914fc812daf2 run #0: crashed: BUG: unable to handle kernel run #1: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #2: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #3: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #4: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #5: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #6: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #7: crashed: BUG: unable to handle kernel run #8: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #9: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #10: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #11: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #12: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #13: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #14: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #15: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #16: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #17: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #18: crashed: BUG: unable to handle kernel NULL pointer dereference in vhci_shutdown_connection run #19: crashed: INFO: task hung in usb_get_descriptor testing current HEAD 4e68c9b0763ff55eaa69d6e519f07515f1c9037b testing commit 4e68c9b0763ff55eaa69d6e519f07515f1c9037b with gcc (GCC) 8.4.1 20210217 kernel signature: ee892321549e71fd71085254b2ecf0b23e9a68a0dde903515ac6716aa32f546f all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 27m20.767796811s (build: 14m43.868570793s, test: 12m13.114430516s) the crash still happens on HEAD commit msg: Linux 4.14.239 crash: unregister_netdevice: waiting for DEV to become free can: request_module (can-proto-0) failed. can: request_module (can-proto-0) failed. unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout