======================================
| [   59.855765][  T271] ==================================================================
| [ 59.856056][ T271] BUG: KASAN: slab-use-after-free in cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
| [   59.856278][  T271] Read of size 8 at addr ffff88800b8500f8 by task kworker/u16:2/271
| [   59.856497][  T271]
[   59.856799][  T271] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   59.856988][  T271] Workqueue: netns cleanup_net
[   59.857142][  T271] Call Trace:
[   59.857255][  T271]  <TASK>
[ 59.857332][ T271] dump_stack_lvl (lib/dump_stack.c:123)
[ 59.857481][ T271] print_address_description.constprop.0 (mm/kasan/report.c:379)
[ 59.857668][ T271] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 59.857822][ T271] print_report (mm/kasan/report.c:490)
[ 59.857966][ T271] ? kasan_addr_to_slab (./include/linux/mm.h:1294 mm/kasan/../slab.h:211 mm/kasan/common.c:38)
[ 59.858105][ T271] kasan_report (mm/kasan/report.c:604)
[ 59.858223][ T271] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 59.858372][ T271] cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 59.858525][ T271] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 59.858672][ T271] ? __pfx_cleanup_net (net/core/net_namespace.c:592)
[ 59.858818][ T271] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 47))
[ 59.858971][ T271] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 59.859114][ T271] ? process_one_work (kernel/workqueue.c:3205)
[ 59.859268][ T271] process_one_work (kernel/workqueue.c:3229)
[ 59.859415][ T271] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 59.859560][ T271] ? __pfx_process_one_work (kernel/workqueue.c:3131)
[ 59.859704][ T271] ? assign_work (kernel/workqueue.c:1200)
[ 59.859854][ T271] worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391)
[ 59.860001][ T271] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 59.860181][ T271] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 59.860333][ T271] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 59.860485][ T271] kthread (kernel/kthread.c:389)
[ 59.860600][ T271] ? __pfx_kthread (kernel/kthread.c:342)
[ 59.860761][ T271] ret_from_fork (arch/x86/kernel/process.c:147)
[ 59.860916][ T271] ? __pfx_kthread (kernel/kthread.c:342)


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