------------[ cut here ]------------ ODEBUG: free active (active state 0) object: ffff88804f942278 object type: timer_list hint: br_ip6_multicast_port_query_expired+0x0/0x380 net/bridge/br_multicast.c:-1 WARNING: lib/debugobjects.c:632 at debug_print_object lib/debugobjects.c:629 [inline], CPU#0: dhcpcd-run-hook/6138 WARNING: lib/debugobjects.c:632 at __debug_check_no_obj_freed lib/debugobjects.c:1116 [inline], CPU#0: dhcpcd-run-hook/6138 WARNING: lib/debugobjects.c:632 at debug_check_no_obj_freed+0x405/0x550 lib/debugobjects.c:1146, CPU#0: dhcpcd-run-hook/6138 Modules linked in: CPU: 0 UID: 0 PID: 6138 Comm: dhcpcd-run-hook Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:debug_print_object lib/debugobjects.c:629 [inline] RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:1116 [inline] RIP: 0010:debug_check_no_obj_freed+0x44a/0x550 lib/debugobjects.c:1146 Code: 89 44 24 20 e8 67 2e 74 fd 48 8b 44 24 20 4c 8b 4d 00 4c 89 ef 48 c7 c6 20 b7 28 8c 48 c7 c2 a0 bc 28 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:ffffc90000007c70 EFLAGS: 00010246 RAX: ffffffff8a7e71f0 RBX: ffffffff9a63ebd0 RCX: 0000000000000000 RDX: ffffffff8c28bca0 RSI: ffffffff8c28b720 RDI: ffffffff903bb0e0 RBP: ffffffff8bcf3a20 R08: ffff88804f942278 R09: ffffffff8bcf4d80 R10: dffffc0000000000 R11: ffffffff81b220d0 R12: ffff88804f942400 R13: ffffffff903bb0e0 R14: ffff88804f942000 R15: ffff88804f942278 FS: 0000000000000000(0000) GS:ffff88812528a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5b8d5a0286 CR3: 00000000403f0000 CR4: 00000000003526f0 Call Trace: slab_free_hook mm/slub.c:2620 [inline] slab_free mm/slub.c:6250 [inline] kfree+0x13e/0x640 mm/slub.c:6565 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x228/0x560 lib/kobject.c:737 rcu_do_batch kernel/rcu/tree.c:2617 [inline] rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0xb/0x3c0 kernel/locking/lockdep.c:5876 Code: be 2f 00 00 00 e9 0e ff ff ff 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 <41> 54 53 48 83 ec 30 49 89 f5 49 89 fe 65 48 8b 05 f0 79 97 11 48 RSP: 0018:ffffc9000398eeb0 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffffff90c42c01 RCX: 0000000080000001 RDX: ffffc9000398f001 RSI: ffffffff8176f256 RDI: ffffffff8e95cde0 RBP: dffffc0000000000 R08: ffffc9000398f090 R09: 0000000000000000 R10: ffffc9000398f058 R11: fffff52000731e0d R12: ffffc9000398f0a0 R13: ffffc90003988000 R14: ffffc9000398f008 R15: ffffffff8176f256 rcu_lock_release include/linux/rcupdate.h:310 [inline] rcu_read_unlock include/linux/rcupdate.h:869 [inline] class_rcu_destructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0x1bba/0x2550 arch/x86/kernel/unwind_orc.c:709 __unwind_start+0x5b8/0x760 arch/x86/kernel/unwind_orc.c:787 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4569 [inline] slab_alloc_node mm/slub.c:4898 [inline] kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4905 kmem_alloc_batch lib/debugobjects.c:371 [inline] fill_pool+0x156/0x580 lib/debugobjects.c:420 debug_objects_fill_pool lib/debugobjects.c:742 [inline] debug_object_activate+0x4a3/0x580 lib/debugobjects.c:831 debug_rcu_head_queue kernel/rcu/rcu.h:236 [inline] __call_rcu_common kernel/rcu/tree.c:3116 [inline] call_rcu+0x43/0x890 kernel/rcu/tree.c:3251 slab_free_hook mm/slub.c:2653 [inline] slab_free mm/slub.c:6250 [inline] kmem_cache_free+0x462/0x650 mm/slub.c:6377 tear_down_vmas+0x312/0x520 mm/mmap.c:1262 exit_mmap+0x4b6/0x9e0 mm/mmap.c:1320 __mmput+0x118/0x430 kernel/fork.c:1178 exec_mmap+0x3b4/0x440 fs/exec.c:893 begin_new_exec+0x134a/0x2480 fs/exec.c:1148 load_elf_binary+0xa47/0x2980 fs/binfmt_elf.c:1010 search_binary_handler fs/exec.c:1664 [inline] exec_binprm fs/exec.c:1696 [inline] bprm_execve+0x94a/0x1510 fs/exec.c:1748 do_execveat_common+0x50d/0x690 fs/exec.c:1846 __do_sys_execve fs/exec.c:1930 [inline] __se_sys_execve fs/exec.c:1924 [inline] __x64_sys_execve+0x97/0xc0 fs/exec.c:1924 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5b8d4e6107 Code: Unable to access opcode bytes at 0x7f5b8d4e60dd. RSP: 002b:00007ffc22f5ed88 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 0000564e6b0fb078 RCX: 00007f5b8d4e6107 RDX: 0000564e6b0fb0a0 RSI: 0000564e6b0fb078 RDI: 0000564e6b0fb130 RBP: 0000564e6b0fb130 R08: 00007ffc22f63e77 R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000246 R12: 0000564e6b0fb0a0 R13: 00007f5b8d6abe8b R14: 0000564e6b0fb0a0 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: 89 44 24 20 mov %eax,0x20(%rsp) 4: e8 67 2e 74 fd call 0xfd742e70 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 20 b7 28 8c mov $0xffffffff8c28b720,%rsi 1c: 48 c7 c2 a0 bc 28 8c mov $0xffffffff8c28bca0,%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