syzbot

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BUG: KCSAN: data-race in coredump_wait / do_group_exit

write to 0xffff88813ac56a20 of 4 bytes by task 25921 on cpu 0:
 zap_process fs/coredump.c:357 [inline]
 zap_threads fs/coredump.c:435 [inline]
 coredump_wait+0x40a/0x900 fs/coredump.c:462
 do_coredump+0x1b8/0x1830 fs/coredump.c:628
 get_signal+0xf36/0x15e0 kernel/signal.c:2782
 arch_do_signal_or_restart+0x2a/0x220 arch/x86/kernel/signal.c:789
 handle_signal_work kernel/entry/common.c:148 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0x109/0x190 kernel/entry/common.c:209
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:302
 do_syscall_64+0x49/0x90 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88813ac56a20 of 4 bytes by task 25928 on cpu 1:
 do_group_exit+0xc1/0x1a0 kernel/exit.c:906
 get_signal+0xfa3/0x15e0 kernel/signal.c:2796
 arch_do_signal_or_restart+0x2a/0x220 arch/x86/kernel/signal.c:789
 handle_signal_work kernel/entry/common.c:148 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0x109/0x190 kernel/entry/common.c:209
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:302
 do_syscall_64+0x49/0x90 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000000 -> 0x00000005

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 25928 Comm: syz-executor.5 Not tainted 5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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