syzbot

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

write to 0xffff8880273695f4 of 4 bytes by task 920 on cpu 0:
 zap_process fs/coredump.c:356 [inline]
 zap_threads fs/coredump.c:435 [inline]
 coredump_wait fs/coredump.c:462 [inline]
 do_coredump+0x4f9/0x1ea0 fs/coredump.c:629
 get_signal+0xf65/0x1510 kernel/signal.c:2752
 arch_do_signal+0x25/0x260 arch/x86/kernel/signal.c:811
 exit_to_user_mode_loop kernel/entry/common.c:161 [inline]
 exit_to_user_mode_prepare+0xde/0x170 kernel/entry/common.c:191
 syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:266
 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880273695f4 of 4 bytes by task 923 on cpu 1:
 signal_group_exit include/linux/sched/signal.h:268 [inline]
 do_group_exit+0x50/0x170 kernel/exit.c:889
 get_signal+0xf9b/0x1510 kernel/signal.c:2758
 arch_do_signal+0x25/0x260 arch/x86/kernel/signal.c:811
 exit_to_user_mode_loop kernel/entry/common.c:161 [inline]
 exit_to_user_mode_prepare+0xde/0x170 kernel/entry/common.c:191
 syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:266
 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 923 Comm: syz-executor.4 Not tainted 5.10.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================