======================================
| [   18.333706][   T63] ==================================================================
| [ 18.333939][ T63] BUG: KASAN: slab-use-after-free in cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
| [   18.334161][   T63] Read of size 8 at addr ffff88800bd980f8 by task kworker/u16:1/63
| [   18.334363][   T63]
[   18.334641][   T63] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   18.334815][   T63] Workqueue: netns cleanup_net
[   18.334959][   T63] Call Trace:
[   18.335063][   T63]  <TASK>
[ 18.335146][ T63] dump_stack_lvl (lib/dump_stack.c:123)
[ 18.335296][ T63] print_address_description.constprop.0 (mm/kasan/report.c:379)
[ 18.335474][ T63] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 18.335612][ T63] print_report (mm/kasan/report.c:490)
[ 18.335751][ T63] ? kasan_addr_to_slab (./include/linux/mm.h:1294 mm/kasan/../slab.h:211 mm/kasan/common.c:38)
[ 18.335888][ T63] kasan_report (mm/kasan/report.c:604)
[ 18.335993][ T63] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 18.336143][ T63] cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 18.336286][ T63] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 18.336429][ T63] ? __pfx_cleanup_net (net/core/net_namespace.c:592)
[ 18.336565][ T63] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 47))
[ 18.336704][ T63] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 18.336842][ T63] ? process_one_work (kernel/workqueue.c:3205)
[ 18.336988][ T63] process_one_work (kernel/workqueue.c:3229)
[ 18.337136][ T63] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 18.337278][ T63] ? __pfx_process_one_work (kernel/workqueue.c:3131)
[ 18.337420][ T63] ? assign_work (kernel/workqueue.c:1200)
[ 18.337559][ T63] worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391)
[ 18.337699][ T63] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 18.337869][ T63] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 18.338013][ T63] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 18.338160][ T63] kthread (kernel/kthread.c:389)
[ 18.338269][ T63] ? __pfx_kthread (kernel/kthread.c:342)
[ 18.338409][ T63] ret_from_fork (arch/x86/kernel/process.c:147)
[ 18.338549][ T63] ? __pfx_kthread (kernel/kthread.c:342)


Finger prints:
print_report:kasan_report:cleanup_net:process_one_work:worker_thread