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BUG: KCSAN: data-race in prepare_signal / ptrace_attach

write to 0xffff88810af24230 of 4 bytes by task 23226 on cpu 0:
 ptrace_attach+0x258/0x520 kernel/ptrace.c:462
 __do_sys_ptrace kernel/ptrace.c:1276 [inline]
 __se_sys_ptrace+0x14c/0x2b0 kernel/ptrace.c:1258
 __x64_sys_ptrace+0x55/0x70 kernel/ptrace.c:1258
 x64_sys_call+0x1fd0/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:102
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88810af24230 of 4 bytes by task 23227 on cpu 1:
 sig_ignored kernel/signal.c:121 [inline]
 prepare_signal+0x45d/0x670 kernel/signal.c:935
 __send_signal_locked+0x31/0x7a0 kernel/signal.c:1053
 send_signal_locked+0x28f/0x3a0 kernel/signal.c:1216
 force_sig_info_to_task+0x1ef/0x280 kernel/signal.c:1320
 force_sig_fault_to_task kernel/signal.c:1699 [inline]
 force_sig_fault+0x79/0xa0 kernel/signal.c:1704
 __bad_area_nosemaphore+0x261/0x320 arch/x86/mm/fault.c:824
 handle_page_fault arch/x86/mm/fault.c:1478 [inline]
 exc_page_fault+0x4e1/0x6a0 arch/x86/mm/fault.c:1538
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

value changed: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 23227 Comm: syz.0.6759 Not tainted 6.15.0-rc2-syzkaller-00048-gc62f4b82d571 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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