======================================
| xx__-> [   11.902955][   T65] ==================================================================
| [ 11.903183][ T65] BUG: KASAN: slab-use-after-free in cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
| [   11.903377][   T65] Read of size 8 at addr ffff88800b9900f8 by task kworker/u16:1/65
| [   11.903563][   T65]
[   11.903844][   T65] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   11.904008][   T65] Workqueue: netns cleanup_net
[   11.904144][   T65] Call Trace:
[   11.904240][   T65]  <TASK>
[ 11.904311][ T65] dump_stack_lvl (lib/dump_stack.c:123)
[ 11.904448][ T65] print_address_description.constprop.0 (mm/kasan/report.c:379)
[ 11.904615][ T65] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 11.904748][ T65] print_report (mm/kasan/report.c:490)
[ 11.904875][ T65] ? kasan_addr_to_slab (./include/linux/mm.h:1294 mm/kasan/../slab.h:211 mm/kasan/common.c:38)
[ 11.905002][ T65] kasan_report (mm/kasan/report.c:604)
[ 11.905101][ T65] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 11.905232][ T65] cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 11.905376][ T65] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 11.905512][ T65] ? __pfx_cleanup_net (net/core/net_namespace.c:592)
[ 11.905640][ T65] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 47))
[ 11.905768][ T65] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 11.905900][ T65] ? process_one_work (kernel/workqueue.c:3205)
[ 11.906029][ T65] process_one_work (kernel/workqueue.c:3229)
[ 11.906153][ T65] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 11.906286][ T65] ? __pfx_process_one_work (kernel/workqueue.c:3131)
[ 11.906418][ T65] ? assign_work (kernel/workqueue.c:1200)
[ 11.906545][ T65] worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391)
[ 11.906671][ T65] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 11.906835][ T65] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 11.906962][ T65] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 11.907094][ T65] kthread (kernel/kthread.c:389)
[ 11.907196][ T65] ? __pfx_kthread (kernel/kthread.c:342)
[ 11.907325][ T65] ret_from_fork (arch/x86/kernel/process.c:147)
[ 11.907457][ T65] ? __pfx_kthread (kernel/kthread.c:342)


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