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BUG: KMSAN: uninit-value in __skb_checksum_complete+0x37f/0x540 net/core/skbuff.c:2850
CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.8.0-rc5-syzkaller #0
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+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
 __skb_checksum_complete+0x37f/0x540 net/core/skbuff.c:2850
 nf_ip_checksum+0x53b/0x740 net/netfilter/utils.c:36
 nf_nat_icmp_reply_translation+0x2ba/0x980 net/netfilter/nf_nat_proto.c:578
 nf_nat_ipv4_fn net/netfilter/nf_nat_proto.c:637 [inline]
 nf_nat_ipv4_local_fn+0x215/0x830 net/netfilter/nf_nat_proto.c:708
 nf_hook_entry_hookfn include/linux/netfilter.h:135 [inline]
 nf_hook_slow+0x16e/0x400 net/netfilter/core.c:512
 nf_hook include/linux/netfilter.h:262 [inline]
 __ip_local_out+0x69b/0x800 net/ipv4/ip_output.c:114
 ip_local_out net/ipv4/ip_output.c:123 [inline]
 ip_send_skb net/ipv4/ip_output.c:1560 [inline]
 ip_push_pending_frames+0x16f/0x460 net/ipv4/ip_output.c:1580
 icmp_push_reply+0x660/0x710 net/ipv4/icmp.c:390
 __icmp_send+0x23ca/0x3150 net/ipv4/icmp.c:740
 ipv4_send_dest_unreach net/ipv4/route.c:1221 [inline]
 ipv4_link_failure+0x7be/0xb70 net/ipv4/route.c:1228
 dst_link_failure include/net/dst.h:426 [inline]
 arp_error_report+0x106/0x1a0 net/ipv4/arp.c:293
 neigh_invalidate+0x33f/0x8c0 net/core/neighbour.c:993
 neigh_timer_handler+0xb0b/0x1520 net/core/neighbour.c:1080
 call_timer_fn+0x218/0x510 kernel/time/timer.c:1404
 expire_timers kernel/time/timer.c:1449 [inline]
 __run_timers+0xd20/0x11c0 kernel/time/timer.c:1773
 run_timer_softirq+0x2d/0x50 kernel/time/timer.c:1786
 __do_softirq+0x311/0x83d kernel/softirq.c:293
 run_ksoftirqd+0x25/0x40 kernel/softirq.c:634
 smpboot_thread_fn+0x493/0x980 kernel/smpboot.c:165
 kthread+0x515/0x550 kernel/kthread.c:292
 ret_from_fork+0x22/0x30 arch/x86/entry/entry_64.S:293

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
 kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:310
 kmsan_memcpy_memmove_metadata+0x272/0x2e0 mm/kmsan/kmsan.c:247
 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:267
 __msan_memcpy+0x43/0x50 mm/kmsan/kmsan_instr.c:116
 csum_partial_copy+0xae/0x100 lib/checksum.c:154
 skb_copy_and_csum_bits+0x757/0x1130 net/core/skbuff.c:2766
 icmp_glue_bits+0x166/0x380 net/ipv4/icmp.c:353
 __ip_append_data+0x47c4/0x5630 net/ipv4/ip_output.c:1131
 ip_append_data+0x328/0x480 net/ipv4/ip_output.c:1315
 icmp_push_reply+0x206/0x710 net/ipv4/icmp.c:371
 __icmp_send+0x23ca/0x3150 net/ipv4/icmp.c:740
 ipv4_send_dest_unreach net/ipv4/route.c:1221 [inline]
 ipv4_link_failure+0x7be/0xb70 net/ipv4/route.c:1228
 dst_link_failure include/net/dst.h:426 [inline]
 arp_error_report+0x106/0x1a0 net/ipv4/arp.c:293
 neigh_invalidate+0x33f/0x8c0 net/core/neighbour.c:993
 neigh_timer_handler+0xb0b/0x1520 net/core/neighbour.c:1080
 call_timer_fn+0x218/0x510 kernel/time/timer.c:1404
 expire_timers kernel/time/timer.c:1449 [inline]
 __run_timers+0xd20/0x11c0 kernel/time/timer.c:1773
 run_timer_softirq+0x2d/0x50 kernel/time/timer.c:1786
 __do_softirq+0x311/0x83d kernel/softirq.c:293

Uninit was created at:
 kmsan_save_stack_with_flags+0x3c/0x90 mm/kmsan/kmsan.c:144
 kmsan_internal_alloc_meta_for_pages mm/kmsan/kmsan_shadow.c:269 [inline]
 kmsan_alloc_page+0xb9/0x180 mm/kmsan/kmsan_shadow.c:293
 __alloc_pages_nodemask+0x56a2/0x5dc0 mm/page_alloc.c:4889
 alloc_pages_current+0x672/0x990 mm/mempolicy.c:2292
 alloc_pages include/linux/gfp.h:545 [inline]
 push_pipe+0x605/0xb70 lib/iov_iter.c:537
 __pipe_get_pages lib/iov_iter.c:1278 [inline]
 pipe_get_pages_alloc lib/iov_iter.c:1385 [inline]
 iov_iter_get_pages_alloc+0x18a9/0x21c0 lib/iov_iter.c:1403
 default_file_splice_read fs/splice.c:385 [inline]
 do_splice_to+0x4fc/0x14f0 fs/splice.c:871
 splice_direct_to_actor+0x45c/0xf50 fs/splice.c:950
 do_splice_direct+0x342/0x580 fs/splice.c:1059
 do_sendfile+0x101b/0x1d40 fs/read_write.c:1540
 __do_sys_sendfile64 fs/read_write.c:1601 [inline]
 __se_sys_sendfile64+0x2bb/0x360 fs/read_write.c:1587
 __x64_sys_sendfile64+0x56/0x70 fs/read_write.c:1587
 do_syscall_64+0xb0/0x150 arch/x86/entry/common.c:386
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
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