======================================
| [   62.698525][  T272] ==================================================================
| [ 62.698818][ T272] BUG: KASAN: slab-use-after-free in cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
| [   62.699037][  T272] Read of size 8 at addr ffff88800b7d00f8 by task kworker/u16:2/272
| [   62.699241][  T272]
[   62.699510][  T272] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   62.699683][  T272] Workqueue: netns cleanup_net
[   62.699831][  T272] Call Trace:
[   62.699938][  T272]  <TASK>
[ 62.700017][ T272] dump_stack_lvl (lib/dump_stack.c:123)
[ 62.700164][ T272] print_address_description.constprop.0 (mm/kasan/report.c:379)
[ 62.700342][ T272] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 62.700484][ T272] print_report (mm/kasan/report.c:490)
[ 62.700617][ T272] ? kasan_addr_to_slab (./include/linux/mm.h:1294 mm/kasan/../slab.h:211 mm/kasan/common.c:38)
[ 62.700754][ T272] kasan_report (mm/kasan/report.c:604)
[ 62.700859][ T272] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 62.700994][ T272] cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 62.701128][ T272] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 62.701268][ T272] ? __pfx_cleanup_net (net/core/net_namespace.c:592)
[ 62.701406][ T272] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 47))
[ 62.701542][ T272] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 62.701685][ T272] ? process_one_work (kernel/workqueue.c:3205)
[ 62.701823][ T272] process_one_work (kernel/workqueue.c:3229)
[ 62.701959][ T272] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 62.702094][ T272] ? __pfx_process_one_work (kernel/workqueue.c:3131)
[ 62.702236][ T272] ? assign_work (kernel/workqueue.c:1200)
[ 62.702370][ T272] worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391)
[ 62.702505][ T272] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 62.702673][ T272] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 62.702814][ T272] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 62.702942][ T272] kthread (kernel/kthread.c:389)
[ 62.703041][ T272] ? __pfx_kthread (kernel/kthread.c:342)
[ 62.703174][ T272] ret_from_fork (arch/x86/kernel/process.c:147)
[ 62.703309][ T272] ? __pfx_kthread (kernel/kthread.c:342)


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