======================================
| [  659.431157][   T65] ==================================================================
| [ 659.431400][ T65] BUG: KASAN: slab-use-after-free in cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
| [  659.431591][   T65] Read of size 8 at addr ffff8880118f1a38 by task kworker/u16:1/65
| [  659.431770][   T65]
[  659.432124][   T65] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  659.432294][   T65] Workqueue: netns cleanup_net
[  659.432444][   T65] Call Trace:
[  659.432559][   T65]  <TASK>
[ 659.432632][ T65] dump_stack_lvl (lib/dump_stack.c:123)
[ 659.432776][ T65] print_address_description.constprop.0 (mm/kasan/report.c:379)
[ 659.432947][ T65] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 659.433080][ T65] print_report (mm/kasan/report.c:490)
[ 659.433205][ T65] ? kasan_addr_to_slab (./include/linux/mm.h:1294 mm/kasan/../slab.h:211 mm/kasan/common.c:38)
[ 659.433338][ T65] kasan_report (mm/kasan/report.c:604)
[ 659.433435][ T65] ? cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 659.433564][ T65] cleanup_net (net/core/net_namespace.c:462 net/core/net_namespace.c:661)
[ 659.433690][ T65] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 659.433820][ T65] ? __pfx_cleanup_net (net/core/net_namespace.c:592)
[ 659.433952][ T65] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 47))
[ 659.434080][ T65] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 659.434205][ T65] ? process_one_work (kernel/workqueue.c:3205)
[ 659.434339][ T65] process_one_work (kernel/workqueue.c:3229)
[ 659.434466][ T65] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 659.434596][ T65] ? __pfx_process_one_work (kernel/workqueue.c:3131)
[ 659.434723][ T65] ? assign_work (kernel/workqueue.c:1200)
[ 659.434847][ T65] worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391)
[ 659.434982][ T65] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 659.435137][ T65] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 659.435261][ T65] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 659.435393][ T65] kthread (kernel/kthread.c:389)
[ 659.435490][ T65] ? __pfx_kthread (kernel/kthread.c:342)
[ 659.435614][ T65] ret_from_fork (arch/x86/kernel/process.c:147)
[ 659.435738][ T65] ? __pfx_kthread (kernel/kthread.c:342)


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