======================================
| [  618.200784][ T5838] ==================================================================
| [ 618.201033][ T5838] BUG: KASAN: slab-use-after-free in cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
| [  618.201234][ T5838] Read of size 8 at addr ffff88800e433078 by task kworker/u16:1/5838
| [  618.201426][ T5838]
[  618.201723][ T5838] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  618.201887][ T5838] Workqueue: netns cleanup_net
[  618.202020][ T5838] Call Trace:
[  618.202118][ T5838]  <TASK>
[ 618.202185][ T5838] dump_stack_lvl (lib/dump_stack.c:123)
[ 618.202323][ T5838] print_address_description.constprop.0 (mm/kasan/report.c:379)
[ 618.202483][ T5838] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 618.202622][ T5838] print_report (mm/kasan/report.c:490)
[ 618.202756][ T5838] ? kasan_addr_to_slab (./include/linux/mm.h:1294 mm/kasan/../slab.h:211 mm/kasan/common.c:38)
[ 618.202888][ T5838] kasan_report (mm/kasan/report.c:604)
[ 618.202988][ T5838] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 618.203119][ T5838] cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 618.203249][ T5838] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 618.203386][ T5838] ? __pfx_cleanup_net (net/core/net_namespace.c:592)
[ 618.203511][ T5838] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 47))
[ 618.203642][ T5838] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 618.203774][ T5838] ? process_one_work (kernel/workqueue.c:3205)
[ 618.203910][ T5838] process_one_work (kernel/workqueue.c:3229)
[ 618.204044][ T5838] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 618.204179][ T5838] ? __pfx_process_one_work (kernel/workqueue.c:3131)
[ 618.204315][ T5838] ? assign_work (kernel/workqueue.c:1200)
[ 618.204447][ T5838] worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391)
[ 618.204577][ T5838] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 618.204744][ T5838] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 618.204875][ T5838] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 618.205005][ T5838] kthread (kernel/kthread.c:389)
[ 618.205110][ T5838] ? __pfx_kthread (kernel/kthread.c:342)
[ 618.205241][ T5838] ret_from_fork (arch/x86/kernel/process.c:147)
[ 618.205371][ T5838] ? __pfx_kthread (kernel/kthread.c:342)


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