KCSAN: data-race in do_exit / ptrace

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in do_exit / ptrace_attach kernel				1	1270d	1270d	0/26	auto-closed as invalid on 2020/12/01 02:40

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BUG: KCSAN: data-race in do_exit / ptrace_attach

write to 0xffff88812fe750b0 of 4 bytes by task 7007 on cpu 0:
 ptrace_attach+0x243/0x510 kernel/ptrace.c:424
 __do_sys_ptrace kernel/ptrace.c:1297 [inline]
 __se_sys_ptrace+0xc1/0x1b0 kernel/ptrace.c:1277
 __x64_sys_ptrace+0x51/0x60 kernel/ptrace.c:1277
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88812fe750b0 of 4 bytes by task 7006 on cpu 1:
 ptrace_event_enabled include/linux/ptrace.h:142 [inline]
 ptrace_event include/linux/ptrace.h:157 [inline]
 do_exit+0xff/0x14a0 kernel/exit.c:765
 do_group_exit+0xa4/0x1a0 kernel/exit.c:922
 __do_sys_exit_group+0xb/0x10 kernel/exit.c:933
 __se_sys_exit_group+0x5/0x10 kernel/exit.c:931
 __x64_sys_exit_group+0x16/0x20 kernel/exit.c:931
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000000 -> 0x00010001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7006 Comm: syz-executor.4 Not tainted 5.15.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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