======================================
| [   30.583119][   T65] ==================================================================
| [ 30.583330][ T65] BUG: KASAN: slab-use-after-free in cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
| [   30.583516][   T65] Read of size 8 at addr ffff888004fb1bf8 by task kworker/u16:1/65
| [   30.583706][   T65]
[   30.583955][   T65] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   30.584114][   T65] Workqueue: netns cleanup_net
[   30.584246][   T65] Call Trace:
[   30.584341][   T65]  <TASK>
[ 30.584408][ T65] dump_stack_lvl (lib/dump_stack.c:123)
[ 30.584538][ T65] print_address_description.constprop.0 (mm/kasan/report.c:379)
[ 30.584699][ T65] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 30.584824][ T65] print_report (mm/kasan/report.c:490)
[ 30.584948][ T65] ? kasan_addr_to_slab (./include/linux/mm.h:1294 mm/kasan/../slab.h:211 mm/kasan/common.c:38)
[ 30.585075][ T65] kasan_report (mm/kasan/report.c:604)
[ 30.585171][ T65] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 30.585297][ T65] cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 30.585421][ T65] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 30.585551][ T65] ? __pfx_cleanup_net (net/core/net_namespace.c:592)
[ 30.585675][ T65] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 47))
[ 30.585801][ T65] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 30.585926][ T65] ? process_one_work (kernel/workqueue.c:3205)
[ 30.586054][ T65] process_one_work (kernel/workqueue.c:3229)
[ 30.586180][ T65] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 30.586306][ T65] ? __pfx_process_one_work (kernel/workqueue.c:3131)
[ 30.586433][ T65] ? assign_work (kernel/workqueue.c:1200)
[ 30.586559][ T65] worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391)
[ 30.586685][ T65] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 30.586842][ T65] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 30.586968][ T65] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 30.587093][ T65] kthread (kernel/kthread.c:389)
[ 30.587189][ T65] ? __pfx_kthread (kernel/kthread.c:342)
[ 30.587313][ T65] ret_from_fork (arch/x86/kernel/process.c:147)
[ 30.587437][ T65] ? __pfx_kthread (kernel/kthread.c:342)


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