bisecting fixing commit since 6a24ca2506d64598eac5d5219e99acca9bde4ca5
building syzkaller on 6436ce4bcd8e2c7dcca0b171ac91f51e96d973f8
testing commit 6a24ca2506d64598eac5d5219e99acca9bde4ca5 with gcc (GCC) 8.4.1 20210217
kernel signature: 795eaef000b831c0bff87de9dbf38fa5f1c2ddcd369cbe57e7a5d83e0b368402
run #0: crashed: WARNING: ODEBUG bug in bt_host_release
run #1: crashed: general protection fault in __queue_work
run #2: crashed: WARNING: ODEBUG bug in bt_host_release
run #3: crashed: WARNING: ODEBUG bug in bt_host_release
run #4: crashed: general protection fault in __queue_work
run #5: crashed: WARNING: ODEBUG bug in bt_host_release
run #6: crashed: WARNING: ODEBUG bug in bt_host_release
run #7: crashed: WARNING: ODEBUG bug in bt_host_release
run #8: crashed: WARNING: ODEBUG bug in bt_host_release
run #9: OK
run #10: OK
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
reproducer seems to be flaky
testing current HEAD 3242aa3a635c0958671ee1e4b0958dcc7c4e5c79
testing commit 3242aa3a635c0958671ee1e4b0958dcc7c4e5c79 with gcc (GCC) 8.4.1 20210217
kernel signature: c3d17b20e2266dfd95010de80e7836c113f349139b71a0e389d37c56b51a327b
run #0: crashed: KASAN: use-after-free Read in __queue_work
run #1: crashed: WARNING: ODEBUG bug in bt_host_release
run #2: crashed: general protection fault in __queue_work
run #3: crashed: general protection fault in __queue_work
run #4: crashed: WARNING: ODEBUG bug in bt_host_release
run #5: crashed: WARNING: ODEBUG bug in bt_host_release
run #6: crashed: WARNING: ODEBUG bug in bt_host_release
run #7: crashed: WARNING: ODEBUG bug in bt_host_release
run #8: crashed: WARNING: ODEBUG bug in bt_host_release
run #9: OK
run #10: OK
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
Reproducer flagged being flaky
revisions tested: 2, total time: 34m22.994102466s (build: 15m31.362023731s, test: 17m55.33505678s)
the crash still happens on HEAD
commit msg: Linux 4.14.222
crash: WARNING: ODEBUG bug in bt_host_release
batman_adv: batadv0: Removing interface: batadv_slave_1
device bridge_slave_1 left promiscuous mode
bridge0: port 2(bridge_slave_1) entered disabled state
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: 18657 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: 18657 Comm: syz-executor.5 Not tainted 4.14.222-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:ffff8881df21fa38 EFLAGS: 00010082
RAX: 0000000000000061 RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000000061 RSI: ffffffff86cbeba0 RDI: ffffed103be43f3e
RBP: ffff8881df21fa60 R08: 0000000000000000 R09: 0000000000000000
R10: fffffbfff13446c9 R11: dffffc0000000000 R12: ffffffff86cb9e20
R13: ffffffff813a25f0 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+0x10d/0x1b0 lib/kobject.c:685
 put_device+0x12/0x20 drivers/base/core.c:2029
 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+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: 0033:0x465029
RSP: 002b:00007ffc09cf9ef8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00000000000000fd RCX: 0000000000465029
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000043
RBP: 00000000004af29c R08: 000000000000000b R09: 0000000000050cc8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000050fec R14: 0000000000050cc8 R15: 0000000000000007

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