bisecting fixing commit since d7e78d08fa77acdea351c8f628f49ca9a0e1029a building syzkaller on 816e0689d7d9d8321f8bf360740f0e516aee15ca testing commit d7e78d08fa77acdea351c8f628f49ca9a0e1029a with gcc (GCC) 8.1.0 kernel signature: 2f603ba27d0b8ad37c2efc69f3a370953e7bc7e99c298f33f23b3f505b4c19bb run #0: crashed: WARNING: ODEBUG bug in bt_host_release run #1: crashed: WARNING: ODEBUG bug in bt_host_release run #2: crashed: WARNING: ODEBUG bug in bt_host_release run #3: crashed: WARNING: ODEBUG bug in bt_host_release run #4: OK run #5: crashed: general protection fault in __queue_work run #6: OK run #7: OK run #8: OK run #9: OK testing current HEAD 5b7a52cd2eef952cee8a72512ef370bcdef46636 testing commit 5b7a52cd2eef952cee8a72512ef370bcdef46636 with gcc (GCC) 8.1.0 kernel signature: 875c8a8a158e92be47faa41ba64111290697100fe82cc601cd91f3599a601a59 run #0: crashed: WARNING: ODEBUG bug in bt_host_release run #1: crashed: WARNING: ODEBUG bug in bt_host_release run #2: crashed: WARNING: ODEBUG bug in bt_host_release run #3: crashed: WARNING: ODEBUG bug in bt_host_release run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK revisions tested: 2, total time: 37m59.291748765s (build: 16m1.973870377s, test: 21m26.686193924s) the crash still happens on HEAD commit msg: Linux 4.14.202 crash: WARNING: ODEBUG bug in bt_host_release Bluetooth: hci1 command 0x0401 tx timeout Bluetooth: hci1 command 0x0401 tx timeout Bluetooth: hci1 command 0x0401 tx timeout ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x90 kernel/workqueue.c:4852 ------------[ cut here ]------------ WARNING: CPU: 1 PID: 739 at lib/debugobjects.c:290 debug_print_object.cold.8+0xa7/0xdb lib/debugobjects.c:287 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 739 Comm: syz-executor.5 Not tainted 4.14.202-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x14b/0x1f1 lib/dump_stack.c:58 panic+0x1b0/0x358 kernel/panic.c:183 __warn.cold.7+0x25/0x2c kernel/panic.c:547 report_bug+0x1a4/0x1f3 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:177 [inline] do_error_trap+0x1bd/0x310 arch/x86/kernel/traps.c:295 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:964 RIP: 0010:debug_print_object.cold.8+0xa7/0xdb lib/debugobjects.c:287 RSP: 0018:ffff888097757788 EFLAGS: 00010082 RAX: 0000000000000061 RBX: 0000000000000003 RCX: 0000000000000000 RDX: 0000000000000061 RSI: ffffffff86cbea20 RDI: ffffed1012eeaee8 RBP: ffff8880977577b0 R08: 0000000000000000 R09: 0000000000000000 R10: fffffbfff13444c9 R11: dffffc0000000000 R12: ffffffff86cb9ca0 R13: ffffffff813b12d0 R14: 0000000000000000 R15: dffffc0000000000 __debug_check_no_obj_freed lib/debugobjects.c:747 [inline] debug_check_no_obj_freed+0x4bc/0x890 lib/debugobjects.c:776 kfree+0xbd/0x270 mm/slab.c:3814 bt_host_release+0x10/0x20 net/bluetooth/hci_sysfs.c:86 device_release+0xd7/0x170 drivers/base/core.c:831 kobject_cleanup lib/kobject.c:646 [inline] kobject_release lib/kobject.c:675 [inline] kref_put include/linux/kref.h:70 [inline] kobject_put+0x10d/0x1b0 lib/kobject.c:692 put_device+0x12/0x20 drivers/base/core.c:2014 hci_free_dev+0x10/0x20 net/bluetooth/hci_core.c:3065 vhci_release+0x73/0xe0 drivers/bluetooth/hci_vhci.c:355 __fput+0x232/0x740 fs/file_table.c:210 ____fput+0x9/0x10 fs/file_table.c:244 task_work_run+0xe5/0x170 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x953/0x2c40 kernel/exit.c:865 do_group_exit+0xf8/0x2c0 kernel/exit.c:962 get_signal+0x2f6/0x1ab0 kernel/signal.c:2423 do_signal+0x7f/0x18b0 arch/x86/kernel/signal.c:814 exit_to_usermode_loop+0x11e/0x190 arch/x86/entry/common.c:160 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x416/0x5b0 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45d5b9 RSP: 002b:00007fd7c8cc8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: fffffffffffffffc RBX: 000000000000f2c0 RCX: 000000000045d5b9 RDX: 0000000020000200 RSI: 00000000800448f0 RDI: 0000000000000004 RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 00007ffc14e37f5f R14: 00007fd7c8cc99c0 R15: 000000000118cf4c ======================================================