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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: 1 PID: 1718 Comm: kworker/u4:30 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
 invoke_softirq kernel/softirq.c:390 [inline]
 __irq_exit_rcu+0x226/0x270 kernel/softirq.c:420
 irq_exit_rcu+0xe/0x10 kernel/softirq.c:432
 sysvec_apic_timer_interrupt+0x107/0x130 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:593
RIP: 0010:kmsan_slab_free+0x8c/0xb0 mm/kmsan/kmsan_hooks.c:109
Code: 00 00 b9 03 00 00 00 e8 12 ea ff ff be ff ff ff ff 65 0f c1 35 f5 dd 31 70 ff ce 75 1a e8 bc 69 2e ff 4c 89 7d e0 ff 75 e0 9d <48> 83 c4 10 5b 41 5e 41 5f 5d c3 0f 0b 48 c7 c7 2a 29 4a 9d 31 c0
RSP: 0018:ffffa30dc2de33e8 EFLAGS: 00000246
RAX: fcbad30b25bf2400 RBX: ffff9469af4eda40 RCX: 0000000000000021
RDX: 0000000000000020 RSI: 0000000000000000 RDI: ffff9468ca735700
RBP: ffffa30dc2de3410 R08: ffffefb80000000f R09: ffff9469afffb000
R10: 0000000000000011 R11: ffffffff9ca0083d R12: ffff9468ca735700
R13: 0000000000000000 R14: ffff9468ca735700 R15: 0000000000000246
 slab_free_freelist_hook mm/slub.c:1507 [inline]
 slab_free mm/slub.c:3088 [inline]
 kmem_cache_free+0x33d/0x2d20 mm/slub.c:3104
 kernfs_put+0x631/0x910 fs/kernfs/dir.c:537
 __kernfs_remove+0x1100/0x11d0 fs/kernfs/dir.c:1344
 kernfs_remove_by_name_ns+0x115/0x1f0 fs/kernfs/dir.c:1516
 kernfs_remove_by_name include/linux/kernfs.h:593 [inline]
 remove_files fs/sysfs/group.c:28 [inline]
 sysfs_remove_group+0x30a/0x610 fs/sysfs/group.c:289
 sysfs_remove_groups+0xd9/0x190 fs/sysfs/group.c:313
 device_remove_groups drivers/base/core.c:1790 [inline]
 device_remove_attrs drivers/base/core.c:1978 [inline]
 device_del+0xd44/0x1fe0 drivers/base/core.c:2856
 netdev_unregister_kobject+0x247/0x2d0 net/core/net-sysfs.c:1854
 rollback_registered_many+0x206d/0x25e0 net/core/dev.c:8995
 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+0x66f/0xbf0 net/ipv4/devinet.c:2695
 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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