------------[ cut here ]------------ ODEBUG: free active (active state 0) object: ffff88807d0f5460 object type: timer_list hint: hci_devcd_timeout+0x0/0x2e0 net/bluetooth/coredump.c:190 WARNING: lib/debugobjects.c:612 at debug_print_object+0x18e/0x2a0 lib/debugobjects.c:612, CPU#0: kworker/0:7/7138 Modules linked in: CPU: 0 UID: 0 PID: 7138 Comm: kworker/0:7 Tainted: G U L syzkaller #0 PREEMPT(full) Tainted: [U]=USER, [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events devcd_del RIP: 0010:debug_print_object+0x19b/0x2a0 lib/debugobjects.c:612 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 02 f5 df 0b 41 56 48 8b 14 dd e0 c6 f2 8b 4c 89 e6 <67> 48 0f b9 3a 58 83 05 5c 7e d6 0b 01 48 83 c4 18 5b 5d 41 5c 41 RSP: 0018:ffffc900035a77e8 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: 0000000000000003 RCX: 0000000000000000 RDX: ffffffff8bf2c620 RSI: ffffffff8bf2c200 RDI: ffffffff909290f0 RBP: 0000000000000001 R08: ffff88807d0f5460 R09: ffffffff8b906c80 R10: ffffffff9088e9d7 R11: ffff88802d618b30 R12: ffffffff8bf2c200 R13: ffffffff8b906cc0 R14: ffffffff8a7e0f10 R15: ffffc900035a78e8 FS: 0000000000000000(0000) GS:ffff8881248fc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc9b6fed58 CR3: 00000000831ae000 CR4: 00000000003526f0 Call Trace: __debug_check_no_obj_freed lib/debugobjects.c:1099 [inline] debug_check_no_obj_freed+0x4b7/0x600 lib/debugobjects.c:1129 free_pages_prepare mm/page_alloc.c:1413 [inline] __free_frozen_pages+0x31a/0x1170 mm/page_alloc.c:2943 hci_release_dev+0x4ef/0x640 net/bluetooth/hci_core.c:2776 bt_host_release+0x6a/0xb0 net/bluetooth/hci_sysfs.c:87 device_release+0xa4/0x240 drivers/base/core.c:2565 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1ef/0x6f0 lib/kobject.c:737 put_device+0x1f/0x30 drivers/base/core.c:3797 devcd_dev_release+0x122/0x170 drivers/base/devcoredump.c:90 device_release+0xa4/0x240 drivers/base/core.c:2565 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1ef/0x6f0 lib/kobject.c:737 put_device+0x1f/0x30 drivers/base/core.c:3797 __devcd_del drivers/base/devcoredump.c:98 [inline] devcd_del+0xaa/0xd0 drivers/base/devcoredump.c:114 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 ---------------- Code disassembly (best guess): 0: b8 00 00 00 00 mov $0x0,%eax 5: 00 fc add %bh,%ah 7: ff (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 02 f5 df 0b lea 0xbdff502(%rip),%rdi # 0xbdff51f 1d: 41 56 push %r14 1f: 48 8b 14 dd e0 c6 f2 mov -0x740d3920(,%rbx,8),%rdx 26: 8b 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 5c 7e d6 0b 01 addl $0x1,0xbd67e5c(%rip) # 0xbd67e93 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