=====================================================
BUG: KMSAN: uninit-value in __hlist_del include/linux/list.h:812 [inline]
BUG: KMSAN: uninit-value in detach_timer kernel/time/timer.c:814 [inline]
BUG: KMSAN: uninit-value in expire_timers kernel/time/timer.c:1438 [inline]
BUG: KMSAN: uninit-value in __run_timers+0xbd9/0x11c0 kernel/time/timer.c:1773
CPU: 0 PID: 885 Comm: kworker/u4:9 Not tainted 5.8.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1df/0x240 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
 __hlist_del include/linux/list.h:812 [inline]
 detach_timer kernel/time/timer.c:814 [inline]
 expire_timers kernel/time/timer.c:1438 [inline]
 __run_timers+0xbd9/0x11c0 kernel/time/timer.c:1773
 run_timer_softirq+0x2d/0x50 kernel/time/timer.c:1786
 __do_softirq+0x311/0x83d kernel/softirq.c:293
 asm_call_on_stack+0x12/0x20 arch/x86/entry/entry_64.S:711
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:23 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:50 [inline]
 do_softirq_own_stack+0x7c/0xa0 arch/x86/kernel/irq_64.c:77
 do_softirq kernel/softirq.c:338 [inline]
 __local_bh_enable_ip+0x184/0x1d0 kernel/softirq.c:190
 local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
 get_next_corpse net/netfilter/nf_conntrack_core.c:2238 [inline]
 nf_ct_iterate_cleanup+0x5b6/0x710 net/netfilter/nf_conntrack_core.c:2261
 nf_ct_iterate_cleanup_net+0x182/0x230 net/netfilter/nf_conntrack_core.c:2346
 masq_device_event+0x10c/0x180 net/netfilter/nf_nat_masquerade.c:88
 notifier_call_chain kernel/notifier.c:83 [inline]
 __raw_notifier_call_chain kernel/notifier.c:361 [inline]
 raw_notifier_call_chain+0x130/0x250 kernel/notifier.c:368
 call_netdevice_notifiers_info net/core/dev.c:2027 [inline]
 call_netdevice_notifiers_extack net/core/dev.c:2039 [inline]
 call_netdevice_notifiers net/core/dev.c:2053 [inline]
 dev_close_many+0x673/0xaf0 net/core/dev.c:1628
 rollback_registered_many+0x8ae/0x25e0 net/core/dev.c:8945
 unregister_netdevice_many net/core/dev.c:10113 [inline]
 default_device_exit_batch+0x73b/0xc60 net/core/dev.c:10596
 ops_exit_list net/core/net_namespace.c:189 [inline]
 cleanup_net+0xf37/0x1a70 net/core/net_namespace.c:603
 process_one_work+0x1540/0x1f30 kernel/workqueue.c:2269
 worker_thread+0xed2/0x23f0 kernel/workqueue.c:2415
 kthread+0x515/0x550 kernel/kthread.c:292
 ret_from_fork+0x22/0x30 arch/x86/entry/entry_64.S:293

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
 kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127
 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:80
 slab_alloc_node mm/slub.c:2839 [inline]
 slab_alloc mm/slub.c:2848 [inline]
 __kmalloc_track_caller+0x8ce/0xef0 mm/slub.c:4447
 kmemdup+0x95/0x140 mm/util.c:127
 __devinet_sysctl_register+0xe4/0x770 net/ipv4/devinet.c:2560
 devinet_init_net+0x5f9/0xbf0 net/ipv4/devinet.c:2691
 ops_init+0x2d3/0x730 net/core/net_namespace.c:151
 setup_net+0x286/0x12b0 net/core/net_namespace.c:341
 copy_net_ns+0x551/0xa70 net/core/net_namespace.c:482
 create_new_namespaces+0x9a8/0x11e0 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x25e/0x340 kernel/nsproxy.c:231
 ksys_unshare+0x8d5/0x1120 kernel/fork.c:2985
 __do_sys_unshare kernel/fork.c:3053 [inline]
 __se_sys_unshare+0x41/0x60 kernel/fork.c:3051
 __x64_sys_unshare+0x32/0x50 kernel/fork.c:3051
 do_syscall_64+0xb0/0x150 arch/x86/entry/common.c:386
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
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