======================================
| xx__-> [   11.210873][   T68] ==================================================================
| [ 11.211240][ T68] BUG: KASAN: slab-use-after-free in cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
| [   11.211556][   T68] Read of size 8 at addr ffff8880066800f8 by task kworker/u16:1/68
| [   11.211851][   T68]
[   11.212292][   T68] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   11.212563][   T68] Workqueue: netns cleanup_net
[   11.212790][   T68] Call Trace:
[   11.212949][   T68]  <TASK>
[ 11.213060][ T68] dump_stack_lvl (lib/dump_stack.c:123)
[ 11.213275][ T68] print_address_description.constprop.0 (mm/kasan/report.c:379)
[ 11.213539][ T68] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 11.213755][ T68] print_report (mm/kasan/report.c:490)
[ 11.213971][ T68] ? kasan_addr_to_slab (./include/linux/mm.h:1294 mm/kasan/../slab.h:211 mm/kasan/common.c:38)
[ 11.214182][ T68] kasan_report (mm/kasan/report.c:604)
[ 11.214347][ T68] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 11.214548][ T68] cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 11.214748][ T68] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 11.214956][ T68] ? __pfx_cleanup_net (net/core/net_namespace.c:592)
[ 11.215145][ T68] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 47))
[ 11.215384][ T68] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 11.215574][ T68] ? process_one_work (kernel/workqueue.c:3205)
[ 11.215764][ T68] process_one_work (kernel/workqueue.c:3229)
[ 11.215954][ T68] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 11.216148][ T68] ? __pfx_process_one_work (kernel/workqueue.c:3131)
[ 11.216342][ T68] ? assign_work (kernel/workqueue.c:1200)
[ 11.216530][ T68] worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391)
[ 11.216714][ T68] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 11.216958][ T68] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 11.217177][ T68] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 11.217383][ T68] kthread (kernel/kthread.c:389)
[ 11.217544][ T68] ? __pfx_kthread (kernel/kthread.c:342)
[ 11.217763][ T68] ret_from_fork (arch/x86/kernel/process.c:147)
[ 11.217959][ T68] ? __pfx_kthread (kernel/kthread.c:342)


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