2009-06-09 07:19:34

by Eibach, Dirk

Subject: [PATCH] char: prevent opening unavailable ports in moxa.c

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 <[email protected]>
---
drivers/char/moxa.c | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)

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 @@ static int moxa_open(struct tty_struct *tty, struct file *filp)
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;
--
1.5.6.5

2009-06-10 15:57:19

by Alan

Subject: Re: [PATCH] char: prevent opening unavailable ports in moxa.c

On Tue, 9 Jun 2009 08:57:36 +0200
Dirk Eibach <[email protected]> wrote:

> 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 <[email protected]>


Applied - thanks

Alan