======================================
| [   22.109764][   T68] ==================================================================
| [ 22.109990][ T68] BUG: KASAN: slab-use-after-free in cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
| [   22.110189][   T68] Read of size 8 at addr ffff8880050000f8 by task kworker/u16:1/68
| [   22.110375][   T68]
[   22.110644][   T68] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   22.110801][   T68] Workqueue: netns cleanup_net
[   22.110936][   T68] Call Trace:
[   22.111035][   T68]  <TASK>
[ 22.111102][ T68] dump_stack_lvl (lib/dump_stack.c:123)
[ 22.111232][ T68] print_address_description.constprop.0 (mm/kasan/report.c:379)
[ 22.111391][ T68] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 22.111515][ T68] print_report (mm/kasan/report.c:490)
[ 22.111641][ T68] ? kasan_addr_to_slab (./include/linux/mm.h:1294 mm/kasan/../slab.h:211 mm/kasan/common.c:38)
[ 22.111765][ T68] kasan_report (mm/kasan/report.c:604)
[ 22.111861][ T68] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 22.111991][ T68] cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 22.112118][ T68] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 22.112248][ T68] ? __pfx_cleanup_net (net/core/net_namespace.c:592)
[ 22.112373][ T68] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 47))
[ 22.112500][ T68] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 22.112625][ T68] ? process_one_work (kernel/workqueue.c:3205)
[ 22.112755][ T68] process_one_work (kernel/workqueue.c:3229)
[ 22.112883][ T68] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 22.113016][ T68] ? __pfx_process_one_work (kernel/workqueue.c:3131)
[ 22.113145][ T68] ? assign_work (kernel/workqueue.c:1200)
[ 22.113270][ T68] worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391)
[ 22.113397][ T68] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 22.113552][ T68] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 22.113686][ T68] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 22.113809][ T68] kthread (kernel/kthread.c:389)
[ 22.113905][ T68] ? __pfx_kthread (kernel/kthread.c:342)
[ 22.114031][ T68] ret_from_fork (arch/x86/kernel/process.c:147)
[ 22.114158][ T68] ? __pfx_kthread (kernel/kthread.c:342)


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