======================================
| xx__-> [   28.462571][   T67] ==================================================================
| [ 28.462789][ T67] BUG: KASAN: slab-use-after-free in cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
| [   28.462981][   T67] Read of size 8 at addr ffff88800b6f80f8 by task kworker/u16:1/67
| [   28.463167][   T67]
[   28.463425][   T67] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   28.463583][   T67] Workqueue: netns cleanup_net
[   28.463716][   T67] Call Trace:
[   28.463814][   T67]  <TASK>
[ 28.463881][ T67] dump_stack_lvl (lib/dump_stack.c:123)
[ 28.464012][ T67] print_address_description.constprop.0 (mm/kasan/report.c:379)
[ 28.464170][ T67] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 28.464298][ T67] print_report (mm/kasan/report.c:490)
[ 28.464421][ T67] ? kasan_addr_to_slab (./include/linux/mm.h:1294 mm/kasan/../slab.h:211 mm/kasan/common.c:38)
[ 28.464546][ T67] kasan_report (mm/kasan/report.c:604)
[ 28.464641][ T67] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 28.464766][ T67] cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 28.464891][ T67] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 28.465024][ T67] ? __pfx_cleanup_net (net/core/net_namespace.c:592)
[ 28.465150][ T67] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 47))
[ 28.465276][ T67] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 28.465404][ T67] ? process_one_work (kernel/workqueue.c:3205)
[ 28.465531][ T67] process_one_work (kernel/workqueue.c:3229)
[ 28.465656][ T67] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 28.465779][ T67] ? __pfx_process_one_work (kernel/workqueue.c:3131)
[ 28.465909][ T67] ? assign_work (kernel/workqueue.c:1200)
[ 28.466032][ T67] worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391)
[ 28.466151][ T67] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 28.466305][ T67] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 28.466431][ T67] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 28.466552][ T67] kthread (kernel/kthread.c:389)
[ 28.466646][ T67] ? __pfx_kthread (kernel/kthread.c:342)
[ 28.466774][ T67] ret_from_fork (arch/x86/kernel/process.c:147)
[ 28.466902][ T67] ? __pfx_kthread (kernel/kthread.c:342)


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