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BUG: KCSAN: data-race in __ip_make_skb / __ip_make_skb

write to 0xffff888107662362 of 2 bytes by task 7454 on cpu 0:
 ip_select_ident_segs include/net/ip.h:533 [inline]
 ip_select_ident include/net/ip.h:547 [inline]
 __ip_make_skb+0x890/0xb90 net/ipv4/ip_output.c:1540
 ip_make_skb+0x237/0x2d0 net/ipv4/ip_output.c:1644
 udp_sendmsg+0x12bd/0x14c0 net/ipv4/udp.c:1249
 inet_sendmsg+0x5f/0x80 net/ipv4/af_inet.c:819
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg net/socket.c:725 [inline]
 ____sys_sendmsg+0x39a/0x510 net/socket.c:2413
 ___sys_sendmsg net/socket.c:2467 [inline]
 __sys_sendmmsg+0x267/0x4c0 net/socket.c:2553
 __do_sys_sendmmsg net/socket.c:2582 [inline]
 __se_sys_sendmmsg net/socket.c:2579 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2579
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888107662362 of 2 bytes by task 7505 on cpu 1:
 ip_select_ident_segs include/net/ip.h:532 [inline]
 ip_select_ident include/net/ip.h:547 [inline]
 __ip_make_skb+0x859/0xb90 net/ipv4/ip_output.c:1540
 ip_make_skb+0x237/0x2d0 net/ipv4/ip_output.c:1644
 udp_sendmsg+0x12bd/0x14c0 net/ipv4/udp.c:1249
 inet_sendmsg+0x5f/0x80 net/ipv4/af_inet.c:819
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg net/socket.c:725 [inline]
 ____sys_sendmsg+0x39a/0x510 net/socket.c:2413
 ___sys_sendmsg net/socket.c:2467 [inline]
 __sys_sendmmsg+0x267/0x4c0 net/socket.c:2553
 __do_sys_sendmmsg net/socket.c:2582 [inline]
 __se_sys_sendmmsg net/socket.c:2579 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2579
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0xbe99 -> 0xbe9a

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7505 Comm: syz-executor.0 Not tainted 5.17.0-rc1-syzkaller-00186-g23a46422c561-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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