======================================
| [   82.694981][   T11] ==================================================================
| [ 82.695463][ T11] BUG: KASAN: slab-use-after-free in __mutex_lock (kernel/locking/mutex.c:587 kernel/locking/mutex.c:752) 
| [   82.695876][   T11] Read of size 8 at addr ffff888006a36868 by task kworker/u8:0/11
| [   82.696315][   T11]
[   82.696858][   T11] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   82.697481][   T11] Workqueue: netns cleanup_net
[   82.697729][   T11] Call Trace:
[   82.697904][   T11]  <TASK>
[ 82.698061][ T11] dump_stack_lvl (lib/dump_stack.c:107) 
[ 82.698303][ T11] print_address_description.constprop.0 (mm/kasan/report.c:378) 
[ 82.698641][ T11] ? __mutex_lock (kernel/locking/mutex.c:587 kernel/locking/mutex.c:752) 
[ 82.698884][ T11] print_report (mm/kasan/report.c:489) 
[ 82.699123][ T11] ? kasan_addr_to_slab (./arch/x86/include/asm/bitops.h:206 ./arch/x86/include/asm/bitops.h:238 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 ./include/linux/page-flags.h:481 mm/kasan/../slab.h:206 mm/kasan/common.c:38) 
[ 82.699381][ T11] kasan_report (mm/kasan/report.c:603) 
[ 82.699602][ T11] ? __mutex_lock (kernel/locking/mutex.c:587 kernel/locking/mutex.c:752) 
[ 82.699846][ T11] __mutex_lock (kernel/locking/mutex.c:587 kernel/locking/mutex.c:752) 
[ 82.700087][ T11] ? __lock_release (kernel/locking/lockdep.c:353 kernel/locking/lockdep.c:5436) 
[ 82.700339][ T11] ? __pfx___lock_release (kernel/locking/lockdep.c:5406) 
[ 82.700606][ T11] ? refcount_dec_and_mutex_lock (./include/linux/instrumented.h:96 ./include/linux/atomic/atomic-instrumented.h:400 ./include/linux/refcount.h:261 ./include/linux/refcount.h:304 ./include/linux/refcount.h:322 lib/refcount.c:119 lib/refcount.c:113) 
[ 82.700931][ T11] ? __pfx___mutex_lock (kernel/locking/mutex.c:751) 
[ 82.701196][ T11] ? __pfx___up_read (kernel/locking/rwsem.c:1339) 
[ 82.701485][ T11] ? refcount_dec_not_one (./arch/x86/include/asm/atomic.h:23 ./include/linux/atomic/atomic-arch-fallback.h:457 ./include/linux/atomic/atomic-instrumented.h:33 lib/refcount.c:76) 
[ 82.701764][ T11] ? tc_setup_cb_destroy (net/sched/cls_api.c:3715) 
[ 82.702049][ T11] ? __pfx_refcount_dec_not_one (lib/refcount.c:75) 
[ 82.702356][ T11] ? refcount_dec_and_mutex_lock (./include/linux/instrumented.h:96 ./include/linux/atomic/atomic-instrumented.h:400 ./include/linux/refcount.h:261 ./include/linux/refcount.h:304 ./include/linux/refcount.h:322 lib/refcount.c:119 lib/refcount.c:113) 
[ 82.702671][ T11] refcount_dec_and_mutex_lock (./include/linux/instrumented.h:96 ./include/linux/atomic/atomic-instrumented.h:400 ./include/linux/refcount.h:261 ./include/linux/refcount.h:304 ./include/linux/refcount.h:322 lib/refcount.c:119 lib/refcount.c:113) 
[ 82.702989][ T11] __tcf_action_put (net/sched/act_api.c:377) 
[ 82.703240][ T11] tcf_action_destroy (net/sched/act_api.c:413 net/sched/act_api.c:393 net/sched/act_api.c:1175) 
[ 82.703494][ T11] tcf_exts_destroy (net/sched/cls_api.c:3312) 
[ 82.703733][ T11] __fl_destroy_filter (./include/net/pkt_cls.h:261 net/sched/cls_flower.c:425) cls_flower
[ 82.704084][ T11] __fl_put (net/sched/cls_flower.c:522 net/sched/cls_flower.c:514) cls_flower
[ 82.704388][ T11] ? __pfx___fl_put (net/sched/cls_flower.c:515) cls_flower
[ 82.704700][ T11] ? __fl_delete (net/sched/cls_flower.c:568) cls_flower
[ 82.705008][ T11] __fl_delete (net/sched/cls_flower.c:574) cls_flower
[ 82.705304][ T11] ? __pfx___fl_delete (net/sched/cls_flower.c:550) cls_flower
[ 82.705626][ T11] ? __lock_release (kernel/locking/lockdep.c:353 kernel/locking/lockdep.c:5436) 
[ 82.705875][ T11] ? __mutex_lock (./arch/x86/include/asm/preempt.h:94 kernel/locking/mutex.c:618 kernel/locking/mutex.c:752) 
[ 82.706129][ T11] fl_destroy (net/sched/cls_flower.c:599) cls_flower
[ 82.706415][ T11] ? __pfx_fl_destroy (net/sched/cls_flower.c:590) cls_flower
[ 82.706724][ T11] ? __pfx___mutex_unlock_slowpath (kernel/locking/mutex.c:907) 
[ 82.707035][ T11] tcf_proto_destroy (net/sched/cls_api.c:418) 
[ 82.707293][ T11] tcf_chain_flush (net/sched/cls_api.c:737) 
[ 82.707539][ T11] __tcf_block_put (net/sched/cls_api.c:1070 net/sched/cls_api.c:1141 net/sched/cls_api.c:1305) 
[ 82.707787][ T11] clsact_destroy (net/sched/sch_ingress.c:302) sch_ingress
[ 82.708098][ T11] __qdisc_destroy (net/sched/sch_generic.c:1067) 
[ 82.708343][ T11] dev_shutdown (net/sched/sch_generic.c:1482) 
[ 82.708576][ T11] unregister_netdevice_many_notify (./include/net/tcx.h:168 net/core/dev.c:11084) 
[ 82.708901][ T11] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11035) 
[ 82.709250][ T11] ? __pfx_tc_action_net_exit_batch_rtnl (net/sched/act_api.c:925) 
[ 82.709579][ T11] ? mutex_is_locked (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2569 ./include/linux/atomic/atomic-long.h:38 ./include/linux/atomic/atomic-instrumented.h:3161 kernel/locking/mutex.c:81 kernel/locking/mutex.c:91) 
[ 82.709824][ T11] ? nexthop_net_exit_batch_rtnl (net/ipv4/nexthop.c:569 net/ipv4/nexthop.c:1918 net/ipv4/nexthop.c:2426 net/ipv4/nexthop.c:3754) 
[ 82.710141][ T11] cleanup_net (net/core/net_namespace.c:633) 
[ 82.710369][ T11] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5719) 
[ 82.710659][ T11] ? __pfx_cleanup_net (net/core/net_namespace.c:581) 
[ 82.710921][ T11] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5725) 
[ 82.711183][ T11] ? process_one_work (kernel/workqueue.c:2609) 
[ 82.711456][ T11] process_one_work (kernel/workqueue.c:2633) 
[ 82.711740][ T11] ? hlock_class (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:228) 
[ 82.711974][ T11] ? __pfx_process_one_work (kernel/workqueue.c:2542) 
[ 82.712276][ T11] ? assign_work (kernel/workqueue.c:1101) 
[ 82.712521][ T11] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[ 82.712772][ T11] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 82.713047][ T11] kthread (kernel/kthread.c:388) 
[ 82.713282][ T11] ? __pfx_kthread (kernel/kthread.c:341) 
[ 82.713526][ T11] ret_from_fork (arch/x86/kernel/process.c:147) 
[ 82.713771][ T11] ? __pfx_kthread (kernel/kthread.c:341) 


Finger prints:
dump_stack_lvl:print_report:kasan_report:__mutex_lock