syzbot

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BUG: KCSAN: data-race in sctp_association_free / sctp_wait_for_connect

write to 0xffff888013a9401c of 1 bytes by task 1001 on cpu 1:
 sctp_association_free+0x153/0x560 net/sctp/associola.c:338
 sctp_cmd_delete_tcb net/sctp/sm_sideeffect.c:930 [inline]
 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1318 [inline]
 sctp_side_effects net/sctp/sm_sideeffect.c:1185 [inline]
 sctp_do_sm+0x2a1d/0x3110 net/sctp/sm_sideeffect.c:1156
 sctp_primitive_SHUTDOWN+0x71/0x80 net/sctp/primitive.c:89
 sctp_shutdown+0xad/0xd0 net/sctp/socket.c:5084
 inet_shutdown+0x17b/0x200 net/ipv4/af_inet.c:893
 __sys_shutdown_sock net/socket.c:2189 [inline]
 __sys_shutdown net/socket.c:2201 [inline]
 __do_sys_shutdown net/socket.c:2209 [inline]
 __se_sys_shutdown+0xf6/0x140 net/socket.c:2207
 __x64_sys_shutdown+0x2d/0x40 net/socket.c:2207
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888013a9401c of 1 bytes by task 997 on cpu 0:
 sctp_wait_for_connect+0x177/0x360 net/sctp/socket.c:9166
 __sctp_connect+0x94f/0xa50 net/sctp/socket.c:1230
 sctp_connect net/sctp/socket.c:4730 [inline]
 sctp_inet_connect+0xe1/0x100 net/sctp/socket.c:4745
 __sys_connect_file net/socket.c:1837 [inline]
 __sys_connect+0x245/0x280 net/socket.c:1854
 __do_sys_connect net/socket.c:1864 [inline]
 __se_sys_connect net/socket.c:1861 [inline]
 __x64_sys_connect+0x3d/0x50 net/socket.c:1861
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 997 Comm: syz-executor.1 Not tainted 5.12.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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