ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x80 kernel/workqueue.c:1563
WARNING: CPU: 1 PID: 267 at lib/debugobjects.c:508 debug_print_object lib/debugobjects.c:505 [inline]
WARNING: CPU: 1 PID: 267 at lib/debugobjects.c:508 __debug_check_no_obj_freed lib/debugobjects.c:987 [inline]
WARNING: CPU: 1 PID: 267 at lib/debugobjects.c:508 debug_check_no_obj_freed+0x44b/0x650 lib/debugobjects.c:1018
Modules linked in:
CPU: 1 PID: 267 Comm: kworker/u4:5 Not tainted 5.11.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
RIP: 0010:debug_print_object lib/debugobjects.c:505 [inline]
RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:987 [inline]
RIP: 0010:debug_check_no_obj_freed+0x44b/0x650 lib/debugobjects.c:1018
Code: 4c 89 ef e8 67 93 d5 fd 4d 8b 45 00 48 c7 c7 60 d8 6d 8a 48 c7 c6 80 d4 6d 8a 48 89 da 44 89 f1 4d 89 f9 31 c0 e8 b5 c2 5c fd <0f> 0b 48 ba 00 00 00 00 00 fc ff df ff 05 ff 79 86 09 48 8b 5c 24
RSP: 0018:ffffc90001b7f728 EFLAGS: 00010246
RAX: 59407907a0fb5500 RBX: ffffffff8a6dda20 RCX: ffff88801228b780
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffff888012f90fd8 R08: ffffffff8163c792 R09: ffffed10173a60b8
R10: ffffed10173a60b8 R11: 0000000000000000 R12: ffff888012f90fd4
R13: ffffffff8a10ac20 R14: 0000000000000000 R15: ffffffff81509b40
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000015a0004 CR3: 000000001d5b4000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 slab_free_hook mm/slub.c:1539 [inline]
 slab_free_freelist_hook+0xc6/0x1a0 mm/slub.c:1580
 slab_free mm/slub.c:3142 [inline]
 kfree+0xd1/0x2a0 mm/slub.c:4124
 device_release+0x98/0x1c0 drivers/base/core.c:1958
 kobject_cleanup+0x1c9/0x280 lib/kobject.c:705
 netdev_run_todo+0xfe9/0x11a0 net/core/dev.c:10350
 default_device_exit_batch+0x710/0x790 net/core/dev.c:11214
 ops_exit_list net/core/net_namespace.c:190 [inline]
 cleanup_net+0x7ec/0xc60 net/core/net_namespace.c:604
 process_one_work+0x833/0x10c0 kernel/workqueue.c:2275
 worker_thread+0xaa4/0x1460 kernel/workqueue.c:2421
 kthread+0x39a/0x3c0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296