Commit a90b0375 authored Jun 18, 2009 by Dirk Eibach Committed by Linus Torvalds Jun 19, 2009

char: moxa, prevent opening unavailable ports



In moxa.c there are 32 minor numbers reserved for each device.  The number
of ports actually available per device is stored in
moxa_board_conf->numPorts.  This number is not considered in moxa_open().
Opening a port that is not available results in a kernel oops.  This patch
adds a test to moxa_open() that prevents opening unavailable ports.

[akpm@linux-foundation.org: avoid multiple returns]
Signed-off-by: Dirk Eibach <eibach@gdsys.de>
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 0b9ce5a2

drivers/char/moxa.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -1189,6 +1189,11 @@ static int moxa_open(struct tty_struct tty, struct file filp)
		return -ENODEV;
		}

		if (port % MAX_PORTS_PER_BOARD >= brd->numPorts) {
		retval = -ENODEV;
		goto out_unlock;
		}

		ch = &brd->ports[port % MAX_PORTS_PER_BOARD];
		ch->port.count++;
		tty->driver_data = ch;
		@@ -1213,8 +1218,8 @@ static int moxa_open(struct tty_struct tty, struct file filp)
		moxa_close_port(tty);
		} else
		ch->port.flags \|= ASYNC_NORMAL_ACTIVE;
		out_unlock:
		mutex_unlock(&moxa_openlock);

		return retval;
		}