bisecting fixing commit since 958e517f4e16952e9a2e2d58fd32d28ae4e23dda
building syzkaller on 6a81331a1d4c744da9204d02ec88d558f7eea9c9
testing commit 958e517f4e16952e9a2e2d58fd32d28ae4e23dda with gcc (GCC) 8.4.1 20210217
kernel signature: 726ef20850f18a3fc4a33b1219ef52045b95bbe66ed0dd4ab803693a5c72b15d
run #0: crashed: WARNING: ODEBUG bug in bt_host_release
run #1: crashed: WARNING: ODEBUG bug in bt_host_release
run #2: crashed: general protection fault in __queue_work
run #3: crashed: WARNING: ODEBUG bug in bt_host_release
run #4: crashed: WARNING: ODEBUG bug in bt_host_release
run #5: crashed: general protection fault in __queue_work
run #6: crashed: KASAN: use-after-free Read in __queue_work
run #7: crashed: KASAN: use-after-free Read in __queue_work
run #8: crashed: KASAN: use-after-free Read in __queue_work
run #9: crashed: WARNING: ODEBUG bug in bt_host_release
run #10: crashed: general protection fault in __queue_work
run #11: OK
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
testing current HEAD 7d7d1c0ab3eb7c8d8f63a126535018007823b207
testing commit 7d7d1c0ab3eb7c8d8f63a126535018007823b207 with gcc (GCC) 8.4.1 20210217
kernel signature: 46b9200c8aba73c472dc47ea2ca18f43553b640b494c1152c10715ede0992453
run #0: crashed: KASAN: use-after-free Read in __queue_work
run #1: crashed: general protection fault in __queue_work
run #2: crashed: general protection fault in __queue_work
run #3: crashed: WARNING: ODEBUG bug in bt_host_release
run #4: crashed: WARNING: ODEBUG bug in bt_host_release
run #5: crashed: KASAN: use-after-free Read in __queue_work
run #6: crashed: WARNING: ODEBUG bug in bt_host_release
run #7: crashed: WARNING: ODEBUG bug in bt_host_release
run #8: OK
run #9: OK
revisions tested: 2, total time: 40m58.35678203s (build: 22m51.484182605s, test: 17m25.99747729s)
the crash still happens on HEAD
commit msg: Linux 4.14.232
crash: WARNING: ODEBUG bug in bt_host_release
Bluetooth: hci0 command 0x0c1a tx timeout
Bluetooth: hci4 command 0x0409 tx timeout
Bluetooth: hci3 command 0x0419 tx timeout
ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x90 kernel/workqueue.c:4859
------------[ cut here ]------------
WARNING: CPU: 1 PID: 8310 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: 8310 Comm: syz-executor.2 Not tainted 4.14.232-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/0x1e7 lib/dump_stack.c:58
 panic+0x1b0/0x358 kernel/panic.c:183
 __warn.cold.7+0x25/0x25 kernel/panic.c:547
 report_bug+0x1a1/0x200 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 fixup_bug arch/x86/kernel/traps.c:172 [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:ffff8880931b7a38 EFLAGS: 00010082
RAX: 0000000000000061 RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000000061 RSI: ffffffff878b9220 RDI: ffffed1012636f3e
RBP: ffff8880931b7a60 R08: 0000000000000000 R09: 0000000000000000
R10: fffffbfff15ec6f1 R11: dffffc0000000000 R12: ffffffff878b44a0
R13: ffffffff8135fbc0 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:846
 kobject_cleanup lib/kobject.c:646 [inline]
 kobject_release lib/kobject.c:675 [inline]
 kref_put include/linux/kref.h:70 [inline]
 kobject_put lib/kobject.c:692 [inline]
 kobject_put+0x14f/0x3d0 lib/kobject.c:685
 put_device+0x12/0x20 drivers/base/core.c:2029
 hci_free_dev+0x10/0x20 net/bluetooth/hci_core.c:3067
 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+0x98b/0x2c90 kernel/exit.c:868
 do_group_exit+0xf8/0x2c0 kernel/exit.c:965
 SYSC_exit_group kernel/exit.c:976 [inline]
 SyS_exit_group+0x18/0x20 kernel/exit.c:974
 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x466459
RSP: 002b:00007fff0e849688 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00000000000003c6 RCX: 0000000000466459
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000043
RBP: 0000000000000000 R08: 0000000000000014 R09: 00000000000003c6
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004bfb46
R13: 0000000000000000 R14: 0000000000000005 R15: 00007fff0e849880

======================================================