Re: [PATCH v4 0/1] MR10424: services: Cancel overlapped IO after timeout.

[Jinoh Kang (＠iamahuman)]

Jinoh Kang (@iamahuman) commented about programs/services/rpc.c:
> if (ret == WAIT_TIMEOUT)
>          {
>              WINE_ERR("receiving command result timed out\n");
> +            if (!CancelIoEx(process->control_pipe, &overlapped))
> +                WINE_ERR("Failed to cancel IO, %#lx\n", GetLastError());
>              *result = ERROR_SERVICE_REQUEST_TIMEOUT;

This has a subtle data race, since `result` doubles as the read buffer here. If the I/O completes right before this statement, then we will overwrite whatever result we have read from the pipe.

The `result` write shall be done after I/O completion.

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https://gitlab.winehq.org/wine/wine/-/merge_requests/10424#note_148871