======================================
| xx__-> [  267.620410][   T12] ==================================================================
| [  267.620594][   T12] BUG: KASAN: slab-use-after-free in idr_for_each (./include/linux/radix-tree.h:424 lib/idr.c:204)
| [  267.620742][   T12] Read of size 8 at addr ff1100000cb296b8 by task kworker/u16:0/12
| [  267.620877][   T12]
[  267.620930][   T12] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  267.620932][   T12] Workqueue: netns cleanup_net
[  267.620938][   T12] Call Trace:
[  267.620939][   T12]  <TASK>
[  267.620942][   T12]  dump_stack_lvl (lib/dump_stack.c:122)
[  267.620947][   T12]  print_address_description.constprop.0 (mm/kasan/report.c:379)
[  267.620952][   T12]  print_report (mm/kasan/report.c:483)
[  267.620953][   T12]  ? idr_for_each (./include/linux/radix-tree.h:424 lib/idr.c:204)
[  267.620955][   T12]  ? __virt_addr_valid (./include/linux/rcupdate.h:981 (discriminator 3) ./include/linux/mmzone.h:2194 (discriminator 3) arch/x86/mm/physaddr.c:54 (discriminator 3))
[  267.620959][   T12]  ? idr_for_each (./include/linux/radix-tree.h:424 lib/idr.c:204)
[  267.620961][   T12]  kasan_report (mm/kasan/report.c:597)
[  267.620965][   T12]  ? idr_for_each (./include/linux/radix-tree.h:424 lib/idr.c:204)
[  267.620968][   T12]  ? rtnl_net_notifyid (net/core/net_namespace.c:628)
[  267.620973][   T12]  idr_for_each (./include/linux/radix-tree.h:424 lib/idr.c:204)
[  267.620975][   T12]  ? idr_find (lib/idr.c:199)
[  267.620978][   T12]  ? __lock_release.isra.0 (kernel/locking/lockdep.c:5536)
[  267.620981][   T12]  ? __up_write (kernel/locking/rwsem.c:1388 (discriminator 3))
[  267.620984][   T12]  ? cleanup_net (net/core/net_namespace.c:656 net/core/net_namespace.c:700)
[  267.620985][   T12]  cleanup_net (net/core/net_namespace.c:658 net/core/net_namespace.c:700)
[  267.620987][   T12]  ? lock_acquire.part.0 (kernel/locking/lockdep.c:470 kernel/locking/lockdep.c:5870)
[  267.620988][   T12]  ? process_one_work (kernel/workqueue.c:3233 (discriminator 1))
[  267.620992][   T12]  ? net_passive_dec (net/core/net_namespace.c:668)
[  267.620993][   T12]  ? rcu_is_watching (./include/linux/context_tracking.h:128 (discriminator 1) kernel/rcu/tree.c:751 (discriminator 1))
[  267.620996][   T12]  ? process_one_work (kernel/workqueue.c:3233 (discriminator 1))
[  267.620998][   T12]  ? lock_acquire (./include/trace/events/lock.h:24 (discriminator 33) kernel/locking/lockdep.c:5831 (discriminator 33))
[  267.620999][   T12]  ? rcu_is_watching (./include/linux/context_tracking.h:128 (discriminator 1) kernel/rcu/tree.c:751 (discriminator 1))
[  267.621001][   T12]  process_one_work (kernel/workqueue.c:3262)
[  267.621004][   T12]  ? pwq_dec_nr_in_flight (kernel/workqueue.c:3159)
[  267.621006][   T12]  ? lock_acquire.part.0 (kernel/locking/lockdep.c:470 kernel/locking/lockdep.c:5870)
[  267.621009][   T12]  ? assign_work (kernel/workqueue.c:1200)
[  267.621011][   T12]  worker_thread (kernel/workqueue.c:3334 (discriminator 2) kernel/workqueue.c:3421 (discriminator 2))
[  267.621014][   T12]  ? process_one_work (kernel/workqueue.c:3367)
[  267.621016][   T12]  kthread (kernel/kthread.c:463)
[  267.621019][   T12]  ? kthread_is_per_cpu (kernel/kthread.c:412)
[  267.621021][   T12]  ? __lock_release.isra.0 (kernel/locking/lockdep.c:5536)
[  267.621022][   T12]  ? rcu_is_watching (./include/linux/context_tracking.h:128 (discriminator 1) kernel/rcu/tree.c:751 (discriminator 1))
[  267.621024][   T12]  ? kthread_is_per_cpu (kernel/kthread.c:412)
[  267.621026][   T12]  ret_from_fork (arch/x86/kernel/process.c:164)
[  267.621030][   T12]  ? arch_exit_to_user_mode_prepare.isra.0 (arch/x86/entry/syscall_64.c:37)
[  267.621032][   T12]  ? __switch_to (./arch/x86/include/asm/cpufeature.h:101 arch/x86/kernel/process_64.c:377 arch/x86/kernel/process_64.c:665)
[  267.621035][   T12]  ? kthread_is_per_cpu (kernel/kthread.c:412)


Finger prints:
print_report:kasan_report:idr_for_each:cleanup_net:process_one_work