Re: [PATCH v3 8/8] serial: exar: fix: fix crash during shutdown if setup fails

[Greg Kroah-Hartman]

On Tue, Apr 16, 2024 at 08:55:35AM -0400, Parker Newman wrote:
> From: Parker Newman <pnewman@xxxxxxxxxxxxxxx>
> 
> If a port fails to register with serial8250_register_8250_port() the
> kernel can crash when shutting down or module removal.
> 
> This is because "priv->line[i]" will be set to a negative error code
> and in the exar_pci_remove() function serial8250_unregister_port() is
> called without checking if the "priv->line[i]" value is valid.
> 
> Signed-off-by: Parker Newman <pnewman@xxxxxxxxxxxxxxx>
> ---
>  drivers/tty/serial/8250/8250_exar.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c
> index 501b9f3e9c89..f5a395ed69d1 100644
> --- a/drivers/tty/serial/8250/8250_exar.c
> +++ b/drivers/tty/serial/8250/8250_exar.c
> @@ -1671,7 +1671,8 @@ static void exar_pci_remove(struct pci_dev *pcidev)
>  	unsigned int i;
> 
>  	for (i = 0; i < priv->nr; i++)
> -		serial8250_unregister_port(priv->line[i]);
> +		if (priv->line[i] >= 0)
> +			serial8250_unregister_port(priv->line[i]);

Is this a bug in the current driver?  If so, can you resend it on its
own so we can get it merged now?

thanks,

greg k-h