======================================
| [   40.501105][  T326] ==================================================================
| [ 40.501556][ T326] BUG: KASAN: slab-use-after-free in cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
| [   40.501948][  T326] Read of size 8 at addr ffff88800bbd00f8 by task kworker/u16:2/326
| [   40.502328][  T326]
[   40.502829][  T326] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   40.503133][  T326] Workqueue: netns cleanup_net
[   40.503421][  T326] Call Trace:
[   40.503660][  T326]  <TASK>
[ 40.503792][ T326] dump_stack_lvl (lib/dump_stack.c:123)
[ 40.504081][ T326] print_address_description.constprop.0 (mm/kasan/report.c:379)
[ 40.504443][ T326] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 40.504727][ T326] print_report (mm/kasan/report.c:490)
[ 40.505051][ T326] ? kasan_addr_to_slab (./include/linux/mm.h:1294 mm/kasan/../slab.h:211 mm/kasan/common.c:38)
[ 40.505325][ T326] kasan_report (mm/kasan/report.c:604)
[ 40.505547][ T326] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 40.505808][ T326] cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 40.506065][ T326] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 40.506339][ T326] ? __pfx_cleanup_net (net/core/net_namespace.c:592)
[ 40.506581][ T326] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 47))
[ 40.506842][ T326] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 40.507088][ T326] ? process_one_work (kernel/workqueue.c:3205)
[ 40.507379][ T326] process_one_work (kernel/workqueue.c:3229)
[ 40.507653][ T326] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 40.507951][ T326] ? __pfx_process_one_work (kernel/workqueue.c:3131)
[ 40.508235][ T326] ? assign_work (kernel/workqueue.c:1200)
[ 40.508511][ T326] worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391)
[ 40.508770][ T326] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 40.509108][ T326] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 40.509372][ T326] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 40.509630][ T326] kthread (kernel/kthread.c:389)
[ 40.509831][ T326] ? __pfx_kthread (kernel/kthread.c:342)
[ 40.510094][ T326] ret_from_fork (arch/x86/kernel/process.c:147)
[ 40.510367][ T326] ? __pfx_kthread (kernel/kthread.c:342)


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