syzbot

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BUG: KCSAN: data-race in copy_creds / rpc_new_client

write to 0xffff8880b42e6818 of 4 bytes by task 24652 on cpu 1:
 get_cred include/linux/cred.h:253 [inline]
 rpc_new_client+0x1b8/0x660 net/sunrpc/clnt.c:398
 rpc_create_xprt+0xb2/0x3d0 net/sunrpc/clnt.c:477
 rpc_create+0x296/0x4a0 net/sunrpc/clnt.c:595
 rpcb_create+0x1be/0x1d0 net/sunrpc/rpcb_clnt.c:393
 rpcb_getport_async+0x376/0x650 net/sunrpc/rpcb_clnt.c:750
 call_bind+0xff/0x140 net/sunrpc/clnt.c:1967
 __rpc_execute+0xf5/0x640 net/sunrpc/sched.c:903
 rpc_execute+0x1b5/0x1c0 net/sunrpc/sched.c:981
 rpc_run_task+0x379/0x440 net/sunrpc/clnt.c:1133
 rpc_call_sync+0xa7/0x130 net/sunrpc/clnt.c:1162
 rpc_ping net/sunrpc/clnt.c:2726 [inline]
 rpc_create_xprt+0x376/0x3d0 net/sunrpc/clnt.c:482
 rpc_create+0x296/0x4a0 net/sunrpc/clnt.c:595
 nfs_create_rpc_client+0x348/0x3c0 fs/nfs/client.c:522
 nfs_init_client fs/nfs/client.c:637 [inline]
 nfs_init_client+0x69/0xc0 fs/nfs/client.c:624

write to 0xffff8880b42e6818 of 4 bytes by task 24651 on cpu 0:
 get_cred include/linux/cred.h:253 [inline]
 copy_creds+0x258/0x340 kernel/cred.c:346
 copy_process+0x926/0x3b50 kernel/fork.c:1884
 _do_fork+0xfe/0x6e0 kernel/fork.c:2366
 __do_sys_clone kernel/fork.c:2521 [inline]
 __se_sys_clone kernel/fork.c:2502 [inline]
 __x64_sys_clone+0x12b/0x160 kernel/fork.c:2502
 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: 0 PID: 24651 Comm: syz-executor.1 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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