syzbot

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BUG: KCSAN: data-race in coredump_wait / coredump_wait

write to 0xffff8881276db06c of 4 bytes by task 13256 on cpu 0:
 freezer_do_not_count include/linux/freezer.h:109 [inline]
 coredump_wait+0x784/0x900 fs/coredump.c:468
 do_coredump+0x1b8/0x17f0 fs/coredump.c:628
 get_signal+0xf56/0x1610 kernel/signal.c:2804
 arch_do_signal_or_restart+0x2a/0x220 arch/x86/kernel/signal.c:789
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x109/0x190 kernel/entry/common.c:208
 irqentry_exit_to_user_mode+0x5/0x20 kernel/entry/common.c:314
 irqentry_exit+0xe/0x30 kernel/entry/common.c:405
 exc_general_protection+0x202/0x340 arch/x86/kernel/traps.c:531
 asm_exc_general_protection+0x1e/0x30 arch/x86/include/asm/idtentry.h:571

read to 0xffff8881276db06c of 4 bytes by task 13261 on cpu 1:
 zap_threads fs/coredump.c:427 [inline]
 coredump_wait+0x2aa/0x900 fs/coredump.c:462
 do_coredump+0x1b8/0x17f0 fs/coredump.c:628
 get_signal+0xf56/0x1610 kernel/signal.c:2804
 arch_do_signal_or_restart+0x2a/0x220 arch/x86/kernel/signal.c:789
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x109/0x190 kernel/entry/common.c:208
 irqentry_exit_to_user_mode+0x5/0x20 kernel/entry/common.c:314
 irqentry_exit+0xe/0x30 kernel/entry/common.c:405
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:577

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 13261 Comm: syz-executor.2 Not tainted 5.13.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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