serial8250: sanity check nr_uarts on all paths.

commit 05d81d2222beec7b63ac8c1c8cdb5bb4f82c2bad upstream

I had 8250.nr_uarts=16 in the boot line of a test kernel and I had a weird
mysterious crash in sysfs.  After taking an 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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index d60705e9d0076a79ea8e44aecb1b88700a2b4a11..fe989c5cd3f84c3af2d062edd5ca0e9aa0e2355b 100644 (file)
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -2564,6 +2564,9 @@ 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;