From: Jan Kiszka <jan.kiszka@siemens.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-serial@vger.kernel.org
Subject: [PATCH] serial: 8250: Prevent kernel crash with nr_uarts=0
Date: Mon, 04 May 2015 18:01:24 +0200 [thread overview]
Message-ID: <554797D4.5080704@siemens.com> (raw)
When nr_uarts was set to 0 (via config or 8250_core.nr_uarts), we crash
early on x86 because serial8250_isa_init_ports dereferences base_ops
which remains NULL. In fact, there is nothing to do for that function if
there are no uarts.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
drivers/tty/serial/8250/8250_core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 4506e40..e1363a40 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -3256,7 +3256,7 @@ static void __init serial8250_isa_init_ports(void)
static int first = 1;
int i, irqflag = 0;
- if (!first)
+ if (!first || nr_uarts == 0)
return;
first = 0;
--
2.1.4
next reply other threads:[~2015-05-04 16:01 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-04 16:01 Jan Kiszka [this message]
2015-05-04 17:02 ` [PATCH] serial: 8250: Prevent kernel crash with nr_uarts=0 Peter Hurley
2015-05-04 17:45 ` Jan Kiszka
2015-05-04 18:52 ` Peter Hurley
2015-05-05 6:26 ` [PATCH] serial: 8250: Do nothing if nr_uarts=0 Jan Kiszka
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