[PATCH] serial8250: Sanity check nr_uarts on all paths.

[PATCH] serial8250: Sanity check nr_uarts on all paths.

[Eric W. Biederman]

I had 8250.nr_uarts=16 in the boot line of a test kernel and I had a
weird mysterious crash in sysfs.  After an taking in depth look I realized
that CONFIG_SERIAL_8250_NR_UARTS was set to 4 and I was walking off
the end of the serial8250_ports array.

Ouch!!!

Don't let this happen to someone else.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 drivers/serial/8250.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 1bc00b7..be95e55 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -2623,6 +2623,9 @@ static struct console serial8250_console = {
 
 static int __init serial8250_console_init(void)
 {
+	if (nr_uarts > UART_NR)
+		nr_uarts = UART_NR;
+
 	serial8250_isa_init_ports();
 	register_console(&serial8250_console);
 	return 0;
-- 
1.5.3.rc6.17.g1911

Re: [PATCH] serial8250: Sanity check nr_uarts on all paths.

[Alan Cox]

On Fri, 11 Jul 2008 12:30:42 -0700
ebiederm@xmission.com (Eric W. Biederman) wrote:

> 
> 
> I had 8250.nr_uarts=16 in the boot line of a test kernel and I had a
> weird mysterious crash in sysfs.  After an taking in depth look I realized
> that CONFIG_SERIAL_8250_NR_UARTS was set to 4 and I was walking off
> the end of the serial8250_ports array.
> 
> Ouch!!!
> 
> Don't let this happen to someone else.
> 
> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

Acked-by: Alan Cox <alan@redhat.com>

Added to ttydev tree but please fire straight at Linus in case he fancies
it for 2.6.26

Re: [PATCH] serial8250: Sanity check nr_uarts on all paths.

[Eric W. Biederman]

I had 8250.nr_uarts=16 in the boot line of a test kernel and I had a
weird mysterious crash in sysfs.  After an taking in depth look I realized
that CONFIG_SERIAL_8250_NR_UARTS was set to 4 and I was walking off
the end of the serial8250_ports array.

Ouch!!!

Don't let this happen to someone else.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Alan Cox <alan@redhat.com>
---

Alan Cox <alan@lxorguk.ukuu.org.uk> writes:

> Added to ttydev tree but please fire straight at Linus in case he fancies
> it for 2.6.26

 drivers/serial/8250.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 1bc00b7..be95e55 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -2623,6 +2623,9 @@ static struct console serial8250_console = {
 
 static int __init serial8250_console_init(void)
 {
+	if (nr_uarts > UART_NR)
+		nr_uarts = UART_NR;
+
 	serial8250_isa_init_ports();
 	register_console(&serial8250_console);
 	return 0;
-- 
1.5.3.rc6.17.g1911