Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751903AbbEDQBh (ORCPT ); Mon, 4 May 2015 12:01:37 -0400 Received: from goliath.siemens.de ([192.35.17.28]:55343 "EHLO goliath.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751548AbbEDQB3 (ORCPT ); Mon, 4 May 2015 12:01:29 -0400 Message-ID: <554797D4.5080704@siemens.com> Date: Mon, 04 May 2015 18:01:24 +0200 From: Jan Kiszka User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); de; rv:1.8.1.12) Gecko/20080226 SUSE/2.0.0.12-1.1 Thunderbird/2.0.0.12 Mnenhy/0.7.5.666 MIME-Version: 1.0 To: Greg Kroah-Hartman CC: Linux Kernel Mailing List , linux-serial@vger.kernel.org Subject: [PATCH] serial: 8250: Prevent kernel crash with nr_uarts=0 Content-Type: text/plain; charset=iso-8859-15 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1031 Lines: 30 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 --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/