KCSAN: data-race in coredump_wait / ptrace

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in coredump_wait / ptrace_stop fs				1	979d	979d	0/26	auto-closed as invalid on 2021/09/16 14:58

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BUG: KCSAN: data-race in coredump_wait / ptrace_stop

write to 0xffff88815e736548 of 8 bytes by task 14064 on cpu 0:
 zap_threads fs/coredump.c:381 [inline]
 coredump_wait+0x5af/0x930 fs/coredump.c:462
 do_coredump+0x1f1/0x1920 fs/coredump.c:628
 get_signal+0xef6/0x15a0 kernel/signal.c:2841
 arch_do_signal_or_restart+0x8c/0x280 arch/x86/kernel/signal.c:865
 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:207
 irqentry_exit_to_user_mode+0x5/0x10 kernel/entry/common.c:313
 irqentry_exit+0xe/0x30 kernel/entry/common.c:404
 exc_general_protection+0x29a/0x3e0 arch/x86/kernel/traps.c:531
 asm_exc_general_protection+0x1e/0x30

read to 0xffff88815e736548 of 8 bytes by task 14062 on cpu 1:
 may_ptrace_stop kernel/signal.c:2165 [inline]
 ptrace_stop+0x2bb/0x670 kernel/signal.c:2263
 do_jobctl_trap kernel/signal.c:2509 [inline]
 get_signal+0x1088/0x15a0 kernel/signal.c:2711
 arch_do_signal_or_restart+0x8c/0x280 arch/x86/kernel/signal.c:865
 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:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:300
 do_syscall_64+0x50/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000000000 -> 0xffffc9000f973b68

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 14062 Comm: syz-executor.5 Tainted: G        W         5.15.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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