------------[ cut here ]------------ ODEBUG: free active (active state 0) object: ffff88804ac34090 object type: timer_list hint: rose_t0timer_expiry+0x0/0x560 net/rose/rose_link.c:-1 WARNING: lib/debugobjects.c:615 at debug_print_object lib/debugobjects.c:612 [inline], CPU#0: syz.3.9135/9715 WARNING: lib/debugobjects.c:615 at __debug_check_no_obj_freed lib/debugobjects.c:1099 [inline], CPU#0: syz.3.9135/9715 WARNING: lib/debugobjects.c:615 at debug_check_no_obj_freed+0x405/0x550 lib/debugobjects.c:1129, CPU#0: syz.3.9135/9715 Modules linked in: CPU: 0 UID: 0 PID: 9715 Comm: syz.3.9135 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:debug_print_object lib/debugobjects.c:612 [inline] RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:1099 [inline] RIP: 0010:debug_check_no_obj_freed+0x44a/0x550 lib/debugobjects.c:1129 Code: 89 44 24 20 e8 b7 6b 7e fd 48 8b 44 24 20 4c 8b 4d 00 4c 89 ef 48 c7 c6 40 6b 27 8c 48 c7 c2 c0 70 27 8c 8b 0c 24 4d 89 f8 50 <67> 48 0f b9 3a 48 83 c4 08 4c 8b 6c 24 18 48 b9 00 00 00 00 00 fc RSP: 0018:ffffc90000007b68 EFLAGS: 00010246 RAX: ffffffff8a888d00 RBX: ffffffff9a4786a0 RCX: 0000000000000000 RDX: ffffffff8c2770c0 RSI: ffffffff8c276b40 RDI: ffffffff901b4570 RBP: ffffffff8bcf4a00 R08: ffff88804ac34090 R09: ffffffff8bcf5d20 R10: dffffc0000000000 R11: ffffffff81b099e0 R12: ffff88804ac34200 R13: ffffffff901b4570 R14: ffff88804ac34000 R15: ffff88804ac34090 FS: 00005555872ff500(0000) GS:ffff8881254b0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2da24220 CR3: 000000004d684000 CR4: 00000000003526f0 Call Trace: slab_free_hook mm/slub.c:2601 [inline] slab_free mm/slub.c:6082 [inline] kfree+0x13a/0x610 mm/slub.c:6399 rose_neigh_put include/net/rose.h:166 [inline] rose_timer_expiry+0x4cb/0x600 net/rose/rose_timer.c:183 call_timer_fn+0x192/0x5a0 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers kernel/time/timer.c:2373 [inline] __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385 run_timer_base kernel/time/timer.c:2394 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404 handle_softirqs+0x22a/0x7c0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x4e/0xb0 kernel/rcu/tree.c:752 Code: ff df 4c 8d 34 dd d0 7d 19 8e 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 dc e6 83 00 48 c7 c3 58 37 18 93 49 03 1e <48> 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 34 8b 03 65 ff 0d 69 RSP: 0018:ffffc900036c7740 EFLAGS: 00000283 RAX: 1ffffffff1c32fba RBX: ffff8880b8633758 RCX: 0000000080000001 RDX: 0000000000000000 RSI: ffffffff8c2764e0 RDI: ffffffff8c2764a0 RBP: ffffffff826b9e1c R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffed10036d9b38 R12: 0000000000000002 R13: ffffffff8e75e0a0 R14: ffffffff8e197dd0 R15: dffffc0000000000 trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x5f/0x330 kernel/locking/lockdep.c:5831 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] class_rcu_constructor include/linux/rcupdate.h:1193 [inline] kernfs_root+0x38/0x230 fs/kernfs/kernfs-internal.h:75 kernfs_unlink_sibling+0x110/0x180 fs/kernfs/dir.c:428 __kernfs_remove+0x3e7/0x660 fs/kernfs/dir.c:1519 kernfs_remove_by_name_ns+0xaf/0x130 fs/kernfs/dir.c:1722 kernfs_remove_by_name include/linux/kernfs.h:633 [inline] remove_files fs/sysfs/group.c:28 [inline] sysfs_remove_group+0xfc/0x2e0 fs/sysfs/group.c:328 sysfs_remove_groups+0x54/0xb0 fs/sysfs/group.c:352 netdev_queue_update_kobjects+0x5d3/0x6c0 net/core/net-sysfs.c:2072 remove_queue_kobjects net/core/net-sysfs.c:2170 [inline] netdev_unregister_kobject+0x11f/0x450 net/core/net-sysfs.c:2325 unregister_netdevice_many_notify+0x1e0e/0x2370 net/core/dev.c:12431 unregister_netdevice_many net/core/dev.c:12459 [inline] unregister_netdevice_queue+0x31f/0x360 net/core/dev.c:12273 unregister_netdevice include/linux/netdevice.h:3408 [inline] __tun_detach+0x6d9/0x15d0 drivers/net/tun.c:621 tun_detach drivers/net/tun.c:637 [inline] tun_chr_close+0x10a/0x1c0 drivers/net/tun.c:3436 __fput+0x44f/0xa70 fs/file_table.c:469 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc6ee19c629 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffcae75de28 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fc6ee417da0 RCX: 00007fc6ee19c629 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fc6ee417da0 R08: 0000000000000006 R09: 0000000000000000 R10: 00007fc6ee417cb0 R11: 0000000000000246 R12: 000000000011e399 R13: 00007fc6ee41609c R14: 000000000011e0fa R15: 00007fc6ee416090 ---------------- Code disassembly (best guess): 0: 89 44 24 20 mov %eax,0x20(%rsp) 4: e8 b7 6b 7e fd call 0xfd7e6bc0 9: 48 8b 44 24 20 mov 0x20(%rsp),%rax e: 4c 8b 4d 00 mov 0x0(%rbp),%r9 12: 4c 89 ef mov %r13,%rdi 15: 48 c7 c6 40 6b 27 8c mov $0xffffffff8c276b40,%rsi 1c: 48 c7 c2 c0 70 27 8c mov $0xffffffff8c2770c0,%rdx 23: 8b 0c 24 mov (%rsp),%ecx 26: 4d 89 f8 mov %r15,%r8 29: 50 push %rax * 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2f: 48 83 c4 08 add $0x8,%rsp 33: 4c 8b 6c 24 18 mov 0x18(%rsp),%r13 38: 48 rex.W 39: b9 00 00 00 00 mov $0x0,%ecx 3e: 00 fc add %bh,%ah