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BUG: KMSAN: uninit-value in __arch_swab32 arch/x86/include/uapi/asm/swab.h:10 [inline]
BUG: KMSAN: uninit-value in __fswab32 include/uapi/linux/swab.h:59 [inline]
BUG: KMSAN: uninit-value in erspan_rcv net/ipv4/ip_gre.c:282 [inline]
BUG: KMSAN: uninit-value in gre_rcv+0x1237/0x1970 net/ipv4/ip_gre.c:420
CPU: 0 PID: 8 Comm: ksoftirqd/0 Not tainted 4.17.0-rc5+ #103
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x185/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x149/0x260 mm/kmsan/kmsan.c:1084
 __msan_warning_32+0x6e/0xc0 mm/kmsan/kmsan_instr.c:686
 __arch_swab32 arch/x86/include/uapi/asm/swab.h:10 [inline]
 __fswab32 include/uapi/linux/swab.h:59 [inline]
 erspan_rcv net/ipv4/ip_gre.c:282 [inline]
 gre_rcv+0x1237/0x1970 net/ipv4/ip_gre.c:420
 gre_rcv+0x2d6/0x3b0 net/ipv4/gre_demux.c:142
 ip_local_deliver_finish+0x881/0xed0 net/ipv4/ip_input.c:215
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip_local_deliver+0x43c/0x4e0 net/ipv4/ip_input.c:256
 dst_input include/net/dst.h:450 [inline]
 ip_rcv_finish+0xa36/0x1d00 net/ipv4/ip_input.c:396
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip_rcv+0x118a/0x16d0 net/ipv4/ip_input.c:492
 __netif_receive_skb_core+0x47ff/0x4ac0 net/core/dev.c:4592
 __netif_receive_skb net/core/dev.c:4657 [inline]
 process_backlog+0x62d/0xe20 net/core/dev.c:5337
 napi_poll net/core/dev.c:5735 [inline]
 net_rx_action+0x7c1/0x1a70 net/core/dev.c:5801
 __do_softirq+0x56d/0x93d kernel/softirq.c:285
 run_ksoftirqd+0x1f/0x40 kernel/softirq.c:646
 smpboot_thread_fn+0x488/0x970 kernel/smpboot.c:164
 kthread+0x4e3/0x6d0 kernel/kthread.c:241
 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:412

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:279 [inline]
 kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:189
 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:315
 kmsan_slab_alloc+0x10/0x20 mm/kmsan/kmsan.c:322
 slab_post_alloc_hook mm/slab.h:446 [inline]
 slab_alloc_node mm/slub.c:2753 [inline]
 __kmalloc_node_track_caller+0xb32/0x11b0 mm/slub.c:4395
 __kmalloc_reserve net/core/skbuff.c:138 [inline]
 __alloc_skb+0x2cb/0x9e0 net/core/skbuff.c:206
 alloc_skb_fclone include/linux/skbuff.h:1030 [inline]
 sk_stream_alloc_skb+0x17c/0xcf0 net/ipv4/tcp.c:875
 tcp_fragment+0x425/0x20e0 net/ipv4/tcp_output.c:1316
 tcp_send_loss_probe+0xa69/0xf00 net/ipv4/tcp_output.c:2508
 tcp_write_timer_handler+0x5e3/0xed0 net/ipv4/tcp_timer.c:569
 tcp_write_timer+0x12b/0x280 net/ipv4/tcp_timer.c:593
 call_timer_fn+0x26a/0x5a0 kernel/time/timer.c:1326
 expire_timers kernel/time/timer.c:1363 [inline]
 __run_timers+0xda7/0x11c0 kernel/time/timer.c:1666
 run_timer_softirq+0x43/0x70 kernel/time/timer.c:1692
 __do_softirq+0x56d/0x93d kernel/softirq.c:285
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