======================================
| [  119.987298][   T67] ==================================================================
| [ 119.987573][ T67] BUG: KASAN: slab-use-after-free in cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
| [  119.987799][   T67] Read of size 8 at addr ffff88800f2500f8 by task kworker/u16:1/67
| [  119.988007][   T67]
[  119.988308][   T67] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  119.988493][   T67] Workqueue: netns cleanup_net
[  119.988651][   T67] Call Trace:
[  119.988762][   T67]  <TASK>
[ 119.988840][ T67] dump_stack_lvl (lib/dump_stack.c:123)
[ 119.988988][ T67] print_address_description.constprop.0 (mm/kasan/report.c:379)
[ 119.989191][ T67] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 119.989343][ T67] print_report (mm/kasan/report.c:490)
[ 119.989492][ T67] ? kasan_addr_to_slab (./include/linux/mm.h:1294 mm/kasan/../slab.h:211 mm/kasan/common.c:38)
[ 119.989636][ T67] kasan_report (mm/kasan/report.c:604)
[ 119.989746][ T67] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 119.989890][ T67] cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 119.990035][ T67] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 119.990194][ T67] ? __pfx_cleanup_net (net/core/net_namespace.c:592)
[ 119.990336][ T67] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 47))
[ 119.990515][ T67] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 119.990682][ T67] ? process_one_work (kernel/workqueue.c:3205)
[ 119.990851][ T67] process_one_work (kernel/workqueue.c:3229)
[ 119.991012][ T67] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 119.991169][ T67] ? __pfx_process_one_work (kernel/workqueue.c:3131)
[ 119.991335][ T67] ? assign_work (kernel/workqueue.c:1200)
[ 119.991497][ T67] worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391)
[ 119.991656][ T67] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 119.991859][ T67] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 119.992021][ T67] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 119.992177][ T67] kthread (kernel/kthread.c:389)
[ 119.992301][ T67] ? __pfx_kthread (kernel/kthread.c:342)
[ 119.992457][ T67] ret_from_fork (arch/x86/kernel/process.c:147)
[ 119.992625][ T67] ? __pfx_kthread (kernel/kthread.c:342)


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