Re: [PATCH] tty: serial: return appropriate error on failure

From: Greg KH
Date: Wed Dec 08 2021 - 00:45:12 EST


On Wed, Dec 08, 2021 at 03:47:41AM +0530, Vihas Mak wrote:
> when a user with CAP_SYS_ADMIN disabled calls ioctl (TIOCSSERIAL),
> uart_set_info() returns 0 instead of -EPERM and the user remains unware
> about what went wrong. Fix this.
>
> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215205
>
> Signed-off-by: Vihas Mak <makvihas@xxxxxxxxx>
> ---
> drivers/tty/serial/serial_core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
> index 61e3dd022..c204bdecc 100644
> --- a/drivers/tty/serial/serial_core.c
> +++ b/drivers/tty/serial/serial_core.c
> @@ -960,7 +960,7 @@ static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
> uport->fifosize = new_info->xmit_fifo_size;
>
> check_and_exit:
> - retval = 0;
> + retval = retval < 0 ? retval : 0;

Please no, do not use ? : unless you have to. Spell it out and use a
real if statement.

thanks,

greg k-h