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.
Signed-off-by: Dirk Eibach <eibach@gdsys.de>
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/char/moxa.c b/drivers/char/moxa.c
index 4a4cab7..65b6ff2 100644
--- a/drivers/char/moxa.c
+++ b/drivers/char/moxa.c
@@ -1184,6 +1184,11 @@
return -ENODEV;
}
+ if (port % MAX_PORTS_PER_BOARD >= brd->numPorts) {
+ mutex_unlock(&moxa_openlock);
+ return -ENODEV;
+ }
+
ch = &brd->ports[port % MAX_PORTS_PER_BOARD];
ch->port.count++;
tty->driver_data = ch;