bisecting fixing commit since d7e78d08fa77acdea351c8f628f49ca9a0e1029a
building syzkaller on 816e0689d7d9d8321f8bf360740f0e516aee15ca
testing commit d7e78d08fa77acdea351c8f628f49ca9a0e1029a with gcc (GCC) 8.1.0
kernel signature: 4737f1fe6ace0d5888b7d637f04753b48e2d8d9fbaf000eb230f62e7bb0bb900
run #0: crashed: WARNING: ODEBUG bug in bt_host_release
run #1: crashed: WARNING: ODEBUG bug in bt_host_release
run #2: crashed: KASAN: use-after-free Read in __queue_work
run #3: crashed: WARNING: ODEBUG bug in bt_host_release
run #4: crashed: general protection fault in __queue_work
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
testing current HEAD 87335852c5d9ec629f80bb2257b9a9945962b719
testing commit 87335852c5d9ec629f80bb2257b9a9945962b719 with gcc (GCC) 8.1.0
kernel signature: b57623e712521eef3b9fd0fe2a089bfdace189e754afea8fbd73570581bdb84e
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: crashed: KASAN: use-after-free Read in __queue_work
run #5: crashed: WARNING: ODEBUG bug in bt_host_release
run #6: OK
run #7: OK
run #8: OK
run #9: OK
revisions tested: 2, total time: 39m25.054973529s (build: 17m50.147434725s, test: 21m4.469335154s)
the crash still happens on HEAD
commit msg: Linux 4.14.209
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: 0 PID: 30770 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: 0 PID: 30770 Comm: syz-executor.0 Not tainted 4.14.209-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:ffff8880a3d4f9a8 EFLAGS: 00010086
RAX: 0000000000000061 RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000000061 RSI: ffffffff86cbeb20 RDI: ffffed10147a9f2c
RBP: ffff8880a3d4f9d0 R08: 0000000000000000 R09: 0000000000000000
R10: fffffbfff13442c9 R11: dffffc0000000000 R12: ffffffff86cb9da0
R13: ffffffff813b16d0 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_dev_put include/net/bluetooth/hci_core.h:997 [inline]
 hci_inquiry+0x509/0x790 net/bluetooth/hci_core.c:1316
 hci_sock_ioctl+0x199/0x600 net/bluetooth/hci_sock.c:1043
 sock_do_ioctl+0x62/0xa0 net/socket.c:974
 sock_ioctl+0x251/0x430 net/socket.c:1071
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x180/0xfb0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x74/0x80 fs/ioctl.c:692
 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45d5b9
RSP: 002b:00007fe162401c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000000f2c0 RCX: 000000000045d5b9
RDX: 0000000020000200 RSI: 00000000800448f0 RDI: 0000000000000004
RBP: 000000000118d0c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118d08c
R13: 00007fff839b4cef R14: 00007fe1624029c0 R15: 000000000118d08c

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