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BUG: KCSAN: data-race in __ip4_datagram_connect / __ip_make_skb

write to 0xffff88810710e32a of 2 bytes by task 25399 on cpu 1:
 __ip4_datagram_connect+0x747/0x7a0 net/ipv4/datagram.c:76
 __ip6_datagram_connect+0xc9/0x7d0 net/ipv6/datagram.c:155
 ip6_datagram_connect+0x2a/0x40 net/ipv6/datagram.c:277
 inet_dgram_connect+0x110/0x1a0 net/ipv4/af_inet.c:581
 __sys_connect_file net/socket.c:1976 [inline]
 __sys_connect+0x197/0x1b0 net/socket.c:1993
 __do_sys_connect net/socket.c:2003 [inline]
 __se_sys_connect net/socket.c:2000 [inline]
 __x64_sys_connect+0x3d/0x50 net/socket.c:2000
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88810710e32a of 2 bytes by task 25398 on cpu 0:
 ip_select_ident_segs include/net/ip.h:532 [inline]
 ip_select_ident include/net/ip.h:547 [inline]
 __ip_make_skb+0x856/0xc00 net/ipv4/ip_output.c:1556
 ip_make_skb+0x238/0x2c0 net/ipv4/ip_output.c:1660
 udp_sendmsg+0x111f/0x1200 net/ipv4/udp.c:1260
 udpv6_sendmsg+0x644/0x14a0
 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:660
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg net/socket.c:734 [inline]
 kernel_sendmsg+0x97/0xd0 net/socket.c:754
 sock_no_sendpage+0x98/0xd0 net/core/sock.c:3241
 kernel_sendpage+0x184/0x300 net/socket.c:3555
 sock_sendpage+0x5a/0x70 net/socket.c:1054
 pipe_to_sendpage+0x128/0x160 fs/splice.c:361
 splice_from_pipe_feed fs/splice.c:415 [inline]
 __splice_from_pipe+0x222/0x4d0 fs/splice.c:559
 splice_from_pipe fs/splice.c:594 [inline]
 generic_splice_sendpage+0x89/0xc0 fs/splice.c:743
 do_splice_from fs/splice.c:764 [inline]
 do_splice+0x956/0xd90 fs/splice.c:1074
 __do_splice fs/splice.c:1139 [inline]
 __do_sys_splice fs/splice.c:1346 [inline]
 __se_sys_splice+0x2a4/0x380 fs/splice.c:1328
 __x64_sys_splice+0x74/0x80 fs/splice.c:1328
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0367 -> 0xe1bb

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 25398 Comm: syz-executor.4 Tainted: G        W          6.1.0-syzkaller-14594-g72a85e2b0a1e-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
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