------------[ cut here ]------------ ODEBUG: free active (active state 0) object: ffff88803f3bd420 object type: timer_list hint: vub300_inactivity_timer_expired+0x0/0x3f0 include/linux/refcount.h:-1 WARNING: lib/debugobjects.c:632 at debug_print_object+0xec/0x230 lib/debugobjects.c:629, CPU#0: kworker/0:3/5676 Modules linked in: CPU: 0 UID: 0 PID: 5676 Comm: kworker/0:3 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: usb_hub_wq hub_event RIP: 0010:debug_print_object+0x18a/0x230 lib/debugobjects.c:629 Code: f8 48 c1 e8 03 80 3c 18 00 74 08 4c 89 ff e8 cd 7f 61 fd 4d 8b 0f 4c 89 ef 48 8b 74 24 08 48 89 ea 44 89 e1 4d 89 f0 ff 34 24 <67> 48 0f b9 3a 48 83 c4 08 ff 05 03 e7 e1 0a 48 83 c4 10 5b 41 5c RSP: 0018:ffffc900057e7238 EFLAGS: 00010246 RAX: 1ffffffff16df000 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: ffffffff8bca6540 RSI: ffffffff8bca5fc0 RDI: ffffffff8fba69d0 RBP: ffffffff8bca6540 R08: ffff88803f3bd420 R09: ffffffff8b6f9380 R10: dffffc0000000000 R11: ffffffff81b1ea50 R12: 0000000000000000 R13: ffffffff8fba69d0 R14: ffff88803f3bd420 R15: ffffffff8b6f8000 FS: 0000000000000000(0000) GS:ffff888125c3a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b322f5ac0 CR3: 0000000038c6c000 CR4: 00000000003526f0 Call Trace: __debug_check_no_obj_freed lib/debugobjects.c:1171 [inline] debug_check_no_obj_freed+0x2e3/0x450 lib/debugobjects.c:1201 slab_free_hook mm/slub.c:2608 [inline] slab_free mm/slub.c:6377 [inline] kfree+0x13e/0x6c0 mm/slub.c:6692 device_release+0xc4/0x1f0 drivers/base/core.c:-1 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x222/0x550 lib/kobject.c:737 vub300_delete drivers/mmc/host/vub300.c:379 [inline] kref_put include/linux/kref.h:65 [inline] vub300_disconnect+0x280/0x2f0 drivers/mmc/host/vub300.c:2388 usb_unbind_interface+0x295/0x9f0 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:618 [inline] __device_release_driver drivers/base/dd.c:1349 [inline] device_release_driver_internal+0x4f5/0x880 drivers/base/dd.c:1372 bus_remove_device+0x449/0x560 drivers/base/bus.c:664 device_del+0x528/0x8f0 drivers/base/core.c:3961 usb_disable_device+0x3d4/0x8d0 drivers/usb/core/message.c:1478 usb_disconnect+0x32d/0x990 drivers/usb/core/hub.c:2345 hub_port_connect drivers/usb/core/hub.c:5415 [inline] hub_port_connect_change drivers/usb/core/hub.c:5715 [inline] port_event drivers/usb/core/hub.c:5879 [inline] hub_event+0x1bb7/0x4cf0 drivers/usb/core/hub.c:5961 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ---------------- Code disassembly (best guess): 0: f8 clc 1: 48 c1 e8 03 shr $0x3,%rax 5: 80 3c 18 00 cmpb $0x0,(%rax,%rbx,1) 9: 74 08 je 0x13 b: 4c 89 ff mov %r15,%rdi e: e8 cd 7f 61 fd call 0xfd617fe0 13: 4d 8b 0f mov (%r15),%r9 16: 4c 89 ef mov %r13,%rdi 19: 48 8b 74 24 08 mov 0x8(%rsp),%rsi 1e: 48 89 ea mov %rbp,%rdx 21: 44 89 e1 mov %r12d,%ecx 24: 4d 89 f0 mov %r14,%r8 27: ff 34 24 push (%rsp) * 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2f: 48 83 c4 08 add $0x8,%rsp 33: ff 05 03 e7 e1 0a incl 0xae1e703(%rip) # 0xae1e73c 39: 48 83 c4 10 add $0x10,%rsp 3d: 5b pop %rbx 3e: 41 5c pop %r12