======================================
| [  620.111708][  T279] ==================================================================
| [ 620.112001][ T279] BUG: KASAN: slab-use-after-free in cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
| [  620.112280][  T279] Read of size 8 at addr ffff88800a483078 by task kworker/u16:2/279
| [  620.112547][  T279]
[  620.112857][  T279] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  620.113069][  T279] Workqueue: netns cleanup_net
[  620.113244][  T279] Call Trace:
[  620.113373][  T279]  <TASK>
[ 620.113445][ T279] dump_stack_lvl (lib/dump_stack.c:123)
[ 620.113589][ T279] print_address_description.constprop.0 (mm/kasan/report.c:379)
[ 620.113770][ T279] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 620.113906][ T279] print_report (mm/kasan/report.c:490)
[ 620.114053][ T279] ? kasan_addr_to_slab (./include/linux/mm.h:1294 mm/kasan/../slab.h:211 mm/kasan/common.c:38)
[ 620.114181][ T279] kasan_report (mm/kasan/report.c:604)
[ 620.114278][ T279] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 620.114410][ T279] cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 620.114551][ T279] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 620.114696][ T279] ? __pfx_cleanup_net (net/core/net_namespace.c:592)
[ 620.114850][ T279] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 47))
[ 620.114984][ T279] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 620.115116][ T279] ? process_one_work (kernel/workqueue.c:3205)
[ 620.115243][ T279] process_one_work (kernel/workqueue.c:3229)
[ 620.115380][ T279] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 620.115519][ T279] ? __pfx_process_one_work (kernel/workqueue.c:3131)
[ 620.115669][ T279] ? assign_work (kernel/workqueue.c:1200)
[ 620.115798][ T279] worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391)
[ 620.115928][ T279] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 620.116089][ T279] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 620.116227][ T279] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 620.116365][ T279] kthread (kernel/kthread.c:389)
[ 620.116467][ T279] ? __pfx_kthread (kernel/kthread.c:342)
[ 620.116601][ T279] ret_from_fork (arch/x86/kernel/process.c:147)
[ 620.116728][ T279] ? __pfx_kthread (kernel/kthread.c:342)


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