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Date:   Wed, 4 Oct 2023 12:05:35 +0300 (EEST)
From:   =?ISO-8859-15?Q?Ilpo_J=E4rvinen?= <ilpo.jarvinen@linux.intel.com>
To:     Tony Lindgren <tony@atomide.com>
cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jiri Slaby <jirislaby@kernel.org>,
        Andy Shevchenko <andriy.shevchenko@intel.com>,
        Dhruva Gole <d-gole@ti.com>,
        John Ogness <john.ogness@linutronix.de>,
        Johan Hovold <johan@kernel.org>,
        Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-serial <linux-serial@vger.kernel.org>
Subject: Re: [PATCH] serial: 8250: Check for valid console index
In-Reply-To: <20231004085511.42645-1-tony@atomide.com>
Message-ID: <1fc2dc1d-33f2-6d65-6bdb-d4c7421cbc57@linux.intel.com>
References: <20231004085511.42645-1-tony@atomide.com>
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On Wed, 4 Oct 2023, Tony Lindgren wrote:

> Let's not allow negative numbers for console index.
> 
> Signed-off-by: Tony Lindgren <tony@atomide.com>
> ---
>  drivers/tty/serial/8250/8250_core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
> --- a/drivers/tty/serial/8250/8250_core.c
> +++ b/drivers/tty/serial/8250/8250_core.c
> @@ -611,7 +611,7 @@ static int univ8250_console_setup(struct console *co, char *options)
>  	 * if so, search for the first available port that does have
>  	 * console support.
>  	 */
> -	if (co->index >= UART_NR)
> +	if (co->index < 0 || co->index >= UART_NR)
>  		co->index = 0;

The inconsistencies how different serial drivers handle this situation 
seem staggering. Perhaps there should be some effort to make the behavior
uniform across them?

-- 
 i.