==================================================================
BUG: KCSAN: data-race in __ptrace_unlink / get_signal

read to 0xffff8880a62590a4 of 4 bytes by task 31276 on cpu 1:
 __ptrace_unlink+0x17d/0x380 kernel/ptrace.c:144
 __ptrace_detach kernel/ptrace.c:523 [inline]
 exit_ptrace+0xb4/0x200 kernel/ptrace.c:583
 forget_original_parent kernel/exit.c:616 [inline]
 exit_notify kernel/exit.c:656 [inline]
 do_exit+0x14d6/0x18c0 kernel/exit.c:818
 do_group_exit+0xb4/0x1c0 kernel/exit.c:895
 get_signal+0x2a2/0x1320 kernel/signal.c:2734
 do_signal+0x2f/0x6c0 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop+0x250/0x2c0 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x384/0x3a0 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8880a62590a4 of 4 bytes by task 31274 on cpu 0:
 get_signal+0x7c7/0x1320 kernel/signal.c:2714
 do_signal+0x2f/0x6c0 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop+0x250/0x2c0 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x384/0x3a0 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 31274 Comm: syz-executor.1 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================