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BUG: KMSAN: uninit-value in __call_rcu+0x4b8/0xef0 kernel/rcu/tree.c:3038
CPU: 0 PID: 7 Comm: ksoftirqd/0 Not tainted 4.16.0+ #87
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x185/0x1d0 lib/dump_stack.c:53
 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:683
 __call_rcu+0x4b8/0xef0 kernel/rcu/tree.c:3038
 call_rcu_sched+0x32/0x40 kernel/rcu/tree.c:3100
 dst_release+0x8f/0x1d0 net/core/dst.c:190
 refdst_drop include/net/dst.h:270 [inline]
 skb_dst_drop include/net/dst.h:282 [inline]
 skb_release_head_state+0xf0/0x520 net/core/skbuff.c:609
 skb_release_all net/core/skbuff.c:626 [inline]
 __kfree_skb net/core/skbuff.c:642 [inline]
 kfree_skb+0x372/0x5f0 net/core/skbuff.c:660
 dst_discard_out net/core/dst.c:48 [inline]
 dst_discard+0x37/0x60 include/net/dst.h:388
 dst_input include/net/dst.h:449 [inline]
 ip_rcv_finish+0xa36/0x1d00 net/ipv4/ip_input.c:397
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip_rcv+0x118f/0x16d0 net/ipv4/ip_input.c:493
 __netif_receive_skb_core+0x47df/0x4a90 net/core/dev.c:4562
 __netif_receive_skb net/core/dev.c:4627 [inline]
 process_backlog+0x62d/0xe20 net/core/dev.c:5307
 napi_poll net/core/dev.c:5705 [inline]
 net_rx_action+0x7c1/0x1a70 net/core/dev.c:5771
 __do_softirq+0x56d/0x93d kernel/softirq.c:285
 run_ksoftirqd+0x1f/0x40 kernel/softirq.c:666
 smpboot_thread_fn+0x488/0x970 kernel/smpboot.c:164
 kthread+0x539/0x720 kernel/kthread.c:239
 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:406

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:293 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:528
 rcu_segcblist_enqueue+0x275/0x2d0 kernel/rcu/rcu_segcblist.c:151
 __call_rcu+0x227/0xef0 kernel/rcu/tree.c:3060
 call_rcu_sched+0x32/0x40 kernel/rcu/tree.c:3100
 release_task+0x24b9/0x2530 kernel/exit.c:223
 exit_notify kernel/exit.c:736 [inline]
 do_exit+0x2d91/0x38d0 kernel/exit.c:887
 do_group_exit+0x1a0/0x360 kernel/exit.c:970
 get_signal+0x1320/0x1f20 kernel/signal.c:2469
 do_signal+0xb8/0x1c80 arch/x86/kernel/signal.c:809
 exit_to_usermode_loop arch/x86/entry/common.c:162 [inline]
 prepare_exit_to_usermode+0x271/0x3a0 arch/x86/entry/common.c:196
 syscall_return_slowpath+0xe9/0x700 arch/x86/entry/common.c:265
 do_syscall_64+0x36d/0x430 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:188
 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:314
 kmem_cache_alloc+0xaab/0xb90 mm/slub.c:2756
 alloc_pid+0x7f/0xce0 kernel/pid.c:168
 copy_process+0x3fb7/0x9bb0 kernel/fork.c:1808
 _do_fork+0x311/0xf00 kernel/fork.c:2088
 SYSC_clone+0xf6/0x110 kernel/fork.c:2195
 SyS_clone+0x77/0xa0 kernel/fork.c:2189
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
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