=====================================================
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+0x38d/0x780 kernel/time/timer.c:1438
CPU: 0 PID: 543 Comm: kworker/u4:6 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+0x21c/0x280 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+0x38d/0x780 kernel/time/timer.c:1438
 __run_timers+0xaf4/0xd30 kernel/time/timer.c:1773
 run_timer_softirq+0x2d/0x50 kernel/time/timer.c:1786
 __do_softirq+0x2ea/0x7f5 kernel/softirq.c:293
 asm_call_on_stack+0xf/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+0x6f0/0x860 net/netfilter/nf_conntrack_core.c:2261
 nf_ct_iterate_cleanup_net+0x1b2/0x260 net/netfilter/nf_conntrack_core.c:2346
 masq_device_event+0x132/0x1a0 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+0x123/0x290 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+0x6ee/0xb30 net/core/dev.c:1628
 rollback_registered_many+0x8ee/0x2820 net/core/dev.c:8945
 unregister_netdevice_many net/core/dev.c:10113 [inline]
 default_device_exit_batch+0x735/0xc50 net/core/dev.c:10596
 ops_exit_list net/core/net_namespace.c:189 [inline]
 cleanup_net+0xf72/0x1b60 net/core/net_namespace.c:603
 process_one_work+0x1688/0x2140 kernel/workqueue.c:2269
 worker_thread+0x10bc/0x2730 kernel/workqueue.c:2415
 kthread+0x551/0x590 kernel/kthread.c:292
 ret_from_fork+0x1f/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+0xbe8/0xe10 mm/slub.c:4447
 kmemdup+0x95/0x140 mm/util.c:127
 __devinet_sysctl_register+0xe4/0x770 net/ipv4/devinet.c:2560
 devinet_sysctl_register+0x344/0x410 net/ipv4/devinet.c:2612
 inetdev_init+0x5fb/0xc10 net/ipv4/devinet.c:276
 inetdev_event+0xd19/0x2100 net/ipv4/devinet.c:1531
 notifier_call_chain kernel/notifier.c:83 [inline]
 __raw_notifier_call_chain kernel/notifier.c:361 [inline]
 raw_notifier_call_chain+0x123/0x290 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]
 register_netdevice+0x3120/0x37d0 net/core/dev.c:9545
 register_vlan_dev+0x6a2/0xeb0 net/8021q/vlan.c:175
 vlan_newlink+0xaa9/0xb60 net/8021q/vlan_netlink.c:187
 __rtnl_newlink net/core/rtnetlink.c:3339 [inline]
 rtnl_newlink+0x2e03/0x3ed0 net/core/rtnetlink.c:3397
 rtnetlink_rcv_msg+0x142b/0x18c0 net/core/rtnetlink.c:5460
 netlink_rcv_skb+0x6d7/0x7e0 net/netlink/af_netlink.c:2469
 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:5478
 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
 netlink_unicast+0x11c8/0x1490 net/netlink/af_netlink.c:1329
 netlink_sendmsg+0x173a/0x1840 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 __sys_sendto+0x9f8/0xca0 net/socket.c:1995
 __do_sys_sendto net/socket.c:2007 [inline]
 __se_sys_sendto+0x107/0x130 net/socket.c:2003
 __x64_sys_sendto+0x6e/0x90 net/socket.c:2003
 do_syscall_64+0xad/0x160 arch/x86/entry/common.c:386
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
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