syzbot

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BUG: KCSAN: data-race in complete_signal / do_group_exit

write to 0xffff88813f545b74 of 4 bytes by task 32253 on cpu 0:
 complete_signal+0x4a5/0x600 kernel/signal.c:1045
 __send_signal+0x680/0x790 kernel/signal.c:1182
 send_signal+0x28b/0x3a0 kernel/signal.c:1245
 do_send_sig_info+0x9b/0xe0 kernel/signal.c:1294
 send_sig_info kernel/signal.c:1633 [inline]
 send_sig+0x4f/0x60 kernel/signal.c:1643
 wait_for_space fs/splice.c:991 [inline]
 splice_file_to_pipe+0x30b/0x360 fs/splice.c:1016
 do_splice+0xc53/0xde0 fs/splice.c:1104
 __do_splice fs/splice.c:1144 [inline]
 __do_sys_splice fs/splice.c:1350 [inline]
 __se_sys_splice+0x2bd/0x3a0 fs/splice.c:1332
 __x64_sys_splice+0x74/0x80 fs/splice.c:1332
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88813f545b74 of 4 bytes by task 32251 on cpu 1:
 signal_group_exit include/linux/sched/signal.h:282 [inline]
 do_group_exit+0x51/0x180 kernel/exit.c:912
 __do_sys_exit_group+0xb/0x10 kernel/exit.c:940
 __se_sys_exit_group+0x5/0x10 kernel/exit.c:938
 __x64_sys_exit_group+0x16/0x20 kernel/exit.c:938
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000002 -> 0x00000004

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 32251 Comm: syz-executor.4 Not tainted 5.16.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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