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BUG: KMSAN: uninit-value in __skb_checksum_complete+0x37f/0x540 net/core/skbuff.c:2850
CPU: 1 PID: 26776 Comm: syz-executor.3 Not tainted 5.8.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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
 __skb_checksum_complete+0x37f/0x540 net/core/skbuff.c:2850
 nf_ip6_checksum+0x501/0x610 net/netfilter/utils.c:91
 nf_nat_icmpv6_reply_translation+0x24b/0x10c0 net/netfilter/nf_nat_proto.c:800
 nf_nat_ipv6_fn+0x394/0x4d0 net/netfilter/nf_nat_proto.c:873
 nf_nat_ipv6_local_fn+0xb0/0x690 net/netfilter/nf_nat_proto.c:946
 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]
 __ip6_local_out+0x56d/0x750 net/ipv6/output_core.c:167
 ip6_local_out+0xa4/0x1d0 net/ipv6/output_core.c:177
 ip6_send_skb net/ipv6/ip6_output.c:1865 [inline]
 ip6_push_pending_frames+0x213/0x4f0 net/ipv6/ip6_output.c:1885
 icmpv6_push_pending_frames+0x674/0x6b0 net/ipv6/icmp.c:304
 icmp6_send+0x32c7/0x3a00 net/ipv6/icmp.c:617
 icmpv6_send+0xe4/0x110 net/ipv6/ip6_icmp.c:43
 __udp6_lib_rcv+0x29ba/0x4060 net/ipv6/udp.c:928
 udpv6_rcv+0x5c/0x70 net/ipv6/udp.c:1017
 ip6_protocol_deliver_rcu+0x14d6/0x22c0 net/ipv6/ip6_input.c:433
 ip6_input_finish net/ipv6/ip6_input.c:474 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ip6_input+0x2af/0x340 net/ipv6/ip6_input.c:483
 dst_input include/net/dst.h:449 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ipv6_rcv+0x683/0x710 net/ipv6/ip6_input.c:307
 __netif_receive_skb_one_core net/core/dev.c:5281 [inline]
 __netif_receive_skb net/core/dev.c:5395 [inline]
 process_backlog+0x72c/0x14e0 net/core/dev.c:6239
 napi_poll net/core/dev.c:6684 [inline]
 net_rx_action+0x746/0x1aa0 net/core/dev.c:6752
 __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
 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
 rcu_read_unlock_bh include/linux/rcupdate.h:723 [inline]
 ip6_finish_output2+0x2111/0x2620 net/ipv6/ip6_output.c:118
 __ip6_finish_output+0x824/0x8e0 net/ipv6/ip6_output.c:143
 ip6_finish_output+0x166/0x410 net/ipv6/ip6_output.c:153
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip6_output+0x60a/0x770 net/ipv6/ip6_output.c:176
 dst_output include/net/dst.h:443 [inline]
 ip6_local_out+0x164/0x1d0 net/ipv6/output_core.c:179
 ip6_send_skb+0xfa/0x390 net/ipv6/ip6_output.c:1865
 udp_v6_send_skb+0x1834/0x1e80 net/ipv6/udp.c:1175
 udpv6_sendmsg+0x4570/0x4940 net/ipv6/udp.c:1473
 inet6_sendmsg+0x276/0x2e0 net/ipv6/af_inet6.c:638
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 kernel_sendmsg+0x24a/0x440 net/socket.c:692
 sock_no_sendpage+0x235/0x300 net/core/sock.c:2853
 kernel_sendpage net/socket.c:3642 [inline]
 sock_sendpage+0x1e1/0x2c0 net/socket.c:945
 pipe_to_sendpage+0x38c/0x4c0 fs/splice.c:448
 splice_from_pipe_feed fs/splice.c:502 [inline]
 __splice_from_pipe+0x565/0xf00 fs/splice.c:626
 splice_from_pipe fs/splice.c:661 [inline]
 generic_splice_sendpage+0x1d5/0x2d0 fs/splice.c:834
 do_splice_from fs/splice.c:846 [inline]
 direct_splice_actor+0x1fd/0x580 fs/splice.c:1016
 splice_direct_to_actor+0x6b2/0xf50 fs/splice.c:971
 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
RIP: 0033:0x45c1d9
Code: Bad RIP value.
RSP: 002b:00007ff11e263c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 0000000000025a00 RCX: 000000000045c1d9
RDX: 0000000000000000 RSI: 0000000000000007 RDI: 0000000000000003
RBP: 000000000078bf48 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000a808 R11: 0000000000000246 R12: 000000000078bf0c
R13: 0000000000c9fb6f R14: 00007ff11e2649c0 R15: 000000000078bf0c

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+0x227/0x1130 net/core/skbuff.c:2737
 icmpv6_getfrag+0x15f/0x350 net/ipv6/icmp.c:319
 __ip6_append_data+0x507b/0x6320 net/ipv6/ip6_output.c:1623
 ip6_append_data+0x3cb/0x660 net/ipv6/ip6_output.c:1757
 icmp6_send+0x308e/0x3a00 net/ipv6/icmp.c:609
 icmpv6_send+0xe4/0x110 net/ipv6/ip6_icmp.c:43
 __udp6_lib_rcv+0x29ba/0x4060 net/ipv6/udp.c:928
 udpv6_rcv+0x5c/0x70 net/ipv6/udp.c:1017
 ip6_protocol_deliver_rcu+0x14d6/0x22c0 net/ipv6/ip6_input.c:433
 ip6_input_finish net/ipv6/ip6_input.c:474 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ip6_input+0x2af/0x340 net/ipv6/ip6_input.c:483
 dst_input include/net/dst.h:449 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ipv6_rcv+0x683/0x710 net/ipv6/ip6_input.c:307
 __netif_receive_skb_one_core net/core/dev.c:5281 [inline]
 __netif_receive_skb net/core/dev.c:5395 [inline]
 process_backlog+0x72c/0x14e0 net/core/dev.c:6239
 napi_poll net/core/dev.c:6684 [inline]
 net_rx_action+0x746/0x1aa0 net/core/dev.c:6752
 __do_softirq+0x311/0x83d kernel/softirq.c: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
 _copy_from_iter_full+0xbfe/0x13b0 lib/iov_iter.c:793
 copy_from_iter_full include/linux/uio.h:156 [inline]
 ip_generic_getfrag+0x14a/0x3c0 net/ipv4/ip_output.c:928
 __ip6_append_data+0x507b/0x6320 net/ipv6/ip6_output.c:1623
 ip6_make_skb+0x6ce/0xcf0 net/ipv6/ip6_output.c:1944
 udpv6_sendmsg+0x42f4/0x4940 net/ipv6/udp.c:1467
 inet6_sendmsg+0x276/0x2e0 net/ipv6/af_inet6.c:638
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 kernel_sendmsg+0x24a/0x440 net/socket.c:692
 sock_no_sendpage+0x235/0x300 net/core/sock.c:2853
 kernel_sendpage net/socket.c:3642 [inline]
 sock_sendpage+0x1e1/0x2c0 net/socket.c:945
 pipe_to_sendpage+0x38c/0x4c0 fs/splice.c:448
 splice_from_pipe_feed fs/splice.c:502 [inline]
 __splice_from_pipe+0x565/0xf00 fs/splice.c:626
 splice_from_pipe fs/splice.c:661 [inline]
 generic_splice_sendpage+0x1d5/0x2d0 fs/splice.c:834
 do_splice_from fs/splice.c:846 [inline]
 direct_splice_actor+0x1fd/0x580 fs/splice.c:1016
 splice_direct_to_actor+0x6b2/0xf50 fs/splice.c:971
 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

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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