==================================================================
BUG: KCSAN: data-race in inet_send_prepare / udp_lib_get_port

write to 0xffff888134e8e04e of 2 bytes by task 26681 on cpu 0:
 udp_lib_get_port+0x4b2/0xe20 net/ipv4/udp.c:308
 udp_v4_get_port+0xde/0xf0 net/ipv4/udp.c:354
 inet_autobind net/ipv4/af_inet.c:183 [inline]
 inet_send_prepare+0xd0/0x210 net/ipv4/af_inet.c:807
 inet_sendmsg+0x29/0x80 net/ipv4/af_inet.c:818
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg net/socket.c:674 [inline]
 __sys_sendto+0x2a8/0x370 net/socket.c:1977
 __do_sys_sendto net/socket.c:1989 [inline]
 __se_sys_sendto net/socket.c:1985 [inline]
 __x64_sys_sendto+0x74/0x90 net/socket.c:1985
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888134e8e04e of 2 bytes by task 26675 on cpu 1:
 inet_send_prepare+0x21/0x210 net/ipv4/af_inet.c:806
 inet_sendmsg+0x29/0x80 net/ipv4/af_inet.c:818
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg net/socket.c:674 [inline]
 __sys_sendto+0x2a8/0x370 net/socket.c:1977
 __do_sys_sendto net/socket.c:1989 [inline]
 __se_sys_sendto net/socket.c:1985 [inline]
 __x64_sys_sendto+0x74/0x90 net/socket.c:1985
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000 -> 0xb363

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 26675 Comm: syz-executor.4 Not tainted 5.13.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================