syzbot

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BUG: KCSAN: data-race in inet_send_prepare / sctp_get_port_local

write to 0xffff88809e0b368e of 2 bytes by task 12270 on cpu 0:
 sctp_get_port_local+0x962/0xba0 net/sctp/socket.c:8305
 sctp_do_bind+0x165/0x360 net/sctp/socket.c:402
 sctp_autobind+0x9f/0xd0 net/sctp/socket.c:8587
 sctp_connect_new_asoc+0x2d2/0x360 net/sctp/socket.c:1061
 sctp_sendmsg_new_asoc net/sctp/socket.c:1680 [inline]
 sctp_sendmsg+0xe31/0x14e0 net/sctp/socket.c:1990
 inet_sendmsg+0x6d/0x90 net/ipv4/af_inet.c:807
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0x9f/0xc0 net/socket.c:657
 __sys_sendto+0x21f/0x320 net/socket.c:1952
 __do_sys_sendto net/socket.c:1964 [inline]
 __se_sys_sendto net/socket.c:1960 [inline]
 __x64_sys_sendto+0x89/0xb0 net/socket.c:1960
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88809e0b368e of 2 bytes by task 12275 on cpu 1:
 inet_send_prepare+0x4a/0x200 net/ipv4/af_inet.c:792
 inet_sendmsg+0x37/0x90 net/ipv4/af_inet.c:804
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0x9f/0xc0 net/socket.c:657
 __sys_sendto+0x21f/0x320 net/socket.c:1952
 __do_sys_sendto net/socket.c:1964 [inline]
 __se_sys_sendto net/socket.c:1960 [inline]
 __x64_sys_sendto+0x89/0xb0 net/socket.c:1960
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 12275 Comm: syz-executor.1 Not tainted 5.4.0-rc7+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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