From 794edf30ee6cd088d5f4079b1d4a4cfe5371203e Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 19 Aug 2019 17:17:54 -0700 Subject: lockdown: Lock down TIOCSSERIAL Lock down TIOCSSERIAL as that can be used to change the ioport and irq settings on a serial port. This only appears to be an issue for the serial drivers that use the core serial code. All other drivers seem to either ignore attempts to change port/irq or give an error. Reported-by: Greg Kroah-Hartman Signed-off-by: David Howells Signed-off-by: Matthew Garrett Reviewed-by: Kees Cook cc: Jiri Slaby Cc: linux-serial@vger.kernel.org Signed-off-by: James Morris --- drivers/tty/serial/serial_core.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/tty/serial') diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 83f4dd0bfd74..bbad407557b9 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include @@ -862,6 +863,10 @@ static int uart_set_info(struct tty_struct *tty, struct tty_port *port, goto check_and_exit; } + retval = security_locked_down(LOCKDOWN_TIOCSSERIAL); + if (retval && (change_irq || change_port)) + goto exit; + /* * Ask the low level driver to verify the settings. */ -- cgit v1.2.3