syzbot

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ODEBUG: free active (active state 0) object: ffff88805e93d438 object type: timer_list hint: hci_devcd_timeout+0x0/0x2e0 net/bluetooth/coredump.c:288
WARNING: lib/debugobjects.c:629 at debug_print_object+0x198/0x2b0 lib/debugobjects.c:629, CPU#0: syz.0.1441/13502
Modules linked in:
CPU: 0 UID: 0 PID: 13502 Comm: syz.0.1441 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:debug_print_object+0x1a5/0x2b0 lib/debugobjects.c:629
Code: b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 4f 48 8d 3d 88 0a df 0b 41 56 48 8b 14 ed 40 76 1e 8c 4c 89 e6 <67> 48 0f b9 3a 58 83 05 b2 42 d4 0b 01 48 83 c4 18 5b 5d 41 5c 41
RSP: 0018:ffffc90004d076f8 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffffc90004d077e0 RCX: 0000000000000000
RDX: ffffffff8c1e7580 RSI: ffffffff8c1e71a0 RDI: ffffffff90e66d10
RBP: 0000000000000003 R08: ffff88805e93d438 R09: ffffffff8bb2e1e0
R10: 0000000000000000 R11: ffffffff81000130 R12: ffffffff8c1e71a0
R13: ffffffff8bb2e220 R14: ffffffff8aa11360 R15: ffffc90004d077f8
FS:  0000000000000000(0000) GS:ffff8881242f6000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f70819adac0 CR3: 000000003faa0000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __debug_check_no_obj_freed lib/debugobjects.c:1154 [inline]
 debug_check_no_obj_freed+0x4da/0x630 lib/debugobjects.c:1184
 __free_pages_prepare mm/page_alloc.c:1413 [inline]
 __free_frozen_pages+0x409/0x1090 mm/page_alloc.c:2950
 hci_release_dev+0x4ef/0x630 net/bluetooth/hci_core.c:2739
 bt_host_release+0x6b/0xb0 net/bluetooth/hci_sysfs.c:87
 device_release+0xd2/0x270 drivers/base/core.c:2636
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1f7/0x640 lib/kobject.c:737
 put_device+0x1f/0x30 drivers/base/core.c:3880
 vhci_release+0x185/0x230 drivers/bluetooth/hci_vhci.c:701
 __fput+0x3ff/0xb50 fs/file_table.c:512
 task_work_run+0x150/0x240 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x951/0x2ae0 kernel/exit.c:1004
 do_group_exit+0xd5/0x2a0 kernel/exit.c:1147
 get_signal+0x1ec7/0x21e0 kernel/signal.c:3038
 arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
 exit_to_user_mode_loop+0x139/0x6f0 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x652/0x840 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f727279ce59
Code: Unable to access opcode bytes at 0x7f727279ce2f.
RSP: 002b:00007f72705b2028 EFLAGS: 00000246 ORIG_RAX: 0000000000000117
RAX: fffffffffffffff2 RBX: 00007f7272a16270 RCX: 00007f727279ce59
RDX: 0000000000000000 RSI: 0002000000000003 RDI: 0000000000000001
RBP: 00007f7272832e6f R08: 0000000000000000 R09: 8000400000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7272a16308 R14: 00007f7272a16270 R15: 00007ffff51b6008
 </TASK>
----------------
Code disassembly (best guess):
   0:	b8 00 00 00 00       	mov    $0x0,%eax
   5:	00 fc                	add    %bh,%ah
   7:	ff                   	lcall  (bad)
   8:	df 48 89             	fisttps -0x77(%rax)
   b:	fa                   	cli
   c:	48 c1 ea 03          	shr    $0x3,%rdx
  10:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
  14:	75 4f                	jne    0x65
  16:	48 8d 3d 88 0a df 0b 	lea    0xbdf0a88(%rip),%rdi        # 0xbdf0aa5
  1d:	41 56                	push   %r14
  1f:	48 8b 14 ed 40 76 1e 	mov    -0x73e189c0(,%rbp,8),%rdx
  26:	8c
  27:	4c 89 e6             	mov    %r12,%rsi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	58                   	pop    %rax
  30:	83 05 b2 42 d4 0b 01 	addl   $0x1,0xbd442b2(%rip)        # 0xbd442e9
  37:	48 83 c4 18          	add    $0x18,%rsp
  3b:	5b                   	pop    %rbx
  3c:	5d                   	pop    %rbp
  3d:	41 5c                	pop    %r12
  3f:	41                   	rex.B