[] ? kobject_release+0x0/0xa0 [] kref_put+0x36/0x70 [] kobject_put+0x27/0x60 [] put_device+0x17/0x20 [] hci_free_dev+0x29/0x30 [] vhci_release+0x36/0x70 [] fput+0xd6/0x1f0 [] filp_close+0x66/0x90 [] sys_close+0x99/0xf0 [] system_call_fastpath+0x16/0x1b That timer was introduced with commit 6bd32326cda(Bluetooth: Use proper timer for hci command timout) Timer seems to be running when the thing is closed. Removing the timer unconditionally fixes the problem. And yes, it needs to be fixed before the HCI_UP check. Signed-off-by: Thomas Gleixner Tested-by: Ingo Molnar Signed-off-by: Gustavo F. Padovan