======================================
| xx__-> [   12.745434][   T11] ==================================================================
| [ 12.745668][ T11] BUG: KASAN: slab-use-after-free in cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
| [   12.745879][   T11] Read of size 8 at addr ffff888004fc00f8 by task kworker/u16:0/11
| [   12.746079][   T11]
[   12.746369][   T11] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.746539][   T11] Workqueue: netns cleanup_net
[   12.746686][   T11] Call Trace:
[   12.746793][   T11]  <TASK>
[ 12.746865][ T11] dump_stack_lvl (lib/dump_stack.c:123)
[ 12.747008][ T11] print_address_description.constprop.0 (mm/kasan/report.c:379)
[ 12.747187][ T11] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 12.747328][ T11] print_report (mm/kasan/report.c:490)
[ 12.747466][ T11] ? kasan_addr_to_slab (./include/linux/mm.h:1294 mm/kasan/../slab.h:211 mm/kasan/common.c:38)
[ 12.747602][ T11] kasan_report (mm/kasan/report.c:604)
[ 12.747707][ T11] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 12.747847][ T11] cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 12.747986][ T11] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 12.748128][ T11] ? __pfx_cleanup_net (net/core/net_namespace.c:592)
[ 12.748265][ T11] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 47))
[ 12.748409][ T11] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 12.748549][ T11] ? process_one_work (kernel/workqueue.c:3205)
[ 12.748690][ T11] process_one_work (kernel/workqueue.c:3229)
[ 12.748832][ T11] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 12.748976][ T11] ? __pfx_process_one_work (kernel/workqueue.c:3131)
[ 12.749117][ T11] ? assign_work (kernel/workqueue.c:1200)
[ 12.749256][ T11] worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391)
[ 12.749404][ T11] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 12.749544][ T11] kthread (kernel/kthread.c:389)
[ 12.749649][ T11] ? __pfx_kthread (kernel/kthread.c:342)
[ 12.749787][ T11] ret_from_fork (arch/x86/kernel/process.c:147)
[ 12.749924][ T11] ? __pfx_kthread (kernel/kthread.c:342)


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