==================================================================
BUG: KCSAN: data-race in complete_signal / do_group_exit

write to 0xffff8880a2a10534 of 4 bytes by task 9041 on cpu 1:
 complete_signal+0x530/0x5e0 kernel/signal.c:1039
 __send_signal+0x5ea/0x870 kernel/signal.c:1175
 send_signal+0x224/0x2b0 kernel/signal.c:1236
 do_send_sig_info+0x5f/0xc0 kernel/signal.c:1285
 send_sig_info kernel/signal.c:1604 [inline]
 send_sig+0x5f/0x80 kernel/signal.c:1614
 splice_pipe_to_pipe fs/splice.c:1573 [inline]
 do_splice+0x985/0xc50 fs/splice.c:1141
 __do_sys_splice fs/splice.c:1447 [inline]
 __se_sys_splice fs/splice.c:1427 [inline]
 __x64_sys_splice+0x20a/0x220 fs/splice.c:1427
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880a2a10534 of 4 bytes by task 9040 on cpu 0:
 do_group_exit+0x7b/0x1c0 kernel/exit.c:882
 __do_sys_exit_group kernel/exit.c:910 [inline]
 __se_sys_exit_group kernel/exit.c:908 [inline]
 __x64_sys_exit_group+0x2e/0x30 kernel/exit.c:908
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 9040 Comm: syz-executor.1 Not tainted 5.6.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================