======================================
| xx__-> [   17.929204][   T69] ==================================================================
| [ 17.929429][ T69] BUG: KASAN: slab-use-after-free in cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
| [   17.929648][   T69] Read of size 8 at addr ffff88800b1b80f8 by task kworker/u16:1/69
| [   17.929826][   T69]
[   17.930083][   T69] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   17.930239][   T69] Workqueue: netns cleanup_net
[   17.930371][   T69] Call Trace:
[   17.930465][   T69]  <TASK>
[ 17.930537][ T69] dump_stack_lvl (lib/dump_stack.c:123)
[ 17.930666][ T69] print_address_description.constprop.0 (mm/kasan/report.c:379)
[ 17.930824][ T69] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 17.930960][ T69] print_report (mm/kasan/report.c:490)
[ 17.931088][ T69] ? kasan_addr_to_slab (./include/linux/mm.h:1294 mm/kasan/../slab.h:211 mm/kasan/common.c:38)
[ 17.931216][ T69] kasan_report (mm/kasan/report.c:604)
[ 17.931312][ T69] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 17.931438][ T69] cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 17.931565][ T69] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 17.931694][ T69] ? __pfx_cleanup_net (net/core/net_namespace.c:592)
[ 17.931817][ T69] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 47))
[ 17.931944][ T69] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 17.932068][ T69] ? process_one_work (kernel/workqueue.c:3205)
[ 17.932197][ T69] process_one_work (kernel/workqueue.c:3229)
[ 17.932322][ T69] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 17.932447][ T69] ? __pfx_process_one_work (kernel/workqueue.c:3131)
[ 17.932575][ T69] ? assign_work (kernel/workqueue.c:1200)
[ 17.932703][ T69] worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391)
[ 17.932827][ T69] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 17.932984][ T69] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 17.933112][ T69] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 17.933238][ T69] kthread (kernel/kthread.c:389)
[ 17.933334][ T69] ? __pfx_kthread (kernel/kthread.c:342)
[ 17.933459][ T69] ret_from_fork (arch/x86/kernel/process.c:147)
[ 17.933584][ T69] ? __pfx_kthread (kernel/kthread.c:342)


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