Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756699Ab3CZXBz (ORCPT ); Tue, 26 Mar 2013 19:01:55 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:53305 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756244Ab3CZXBu (ORCPT ); Tue, 26 Mar 2013 19:01:50 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kirill Tkhai , David Miller Subject: [ 02/49] sunsu: Fix panic in case of nonexistent port at "console=ttySY" cmdline option Date: Tue, 26 Mar 2013 16:00:59 -0700 Message-Id: <20130326225839.805395627@linuxfoundation.org> X-Mailer: git-send-email 1.8.1.rc1.5.g7e0651a In-Reply-To: <20130326225839.554028294@linuxfoundation.org> References: <20130326225839.554028294@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3526 Lines: 125 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tkhai Kirill [ Upstream commit cb29529ea0030e60ef1bbbf8399a43d397a51526 ] If a machine has X (X < 4) sunsu ports and cmdline option "console=ttySY" is passed, where X < Y <= 4, than the following panic happens: Unable to handle kernel NULL pointer dereference TPC: RPC: I7: Call Trace: [0000000000453a38] register_console+0x378/0x3e0 [0000000000576fa0] uart_add_one_port+0x2e0/0x340 [000000000057af40] su_probe+0x160/0x2e0 [00000000005b8a4c] platform_drv_probe+0xc/0x20 [00000000005b6c2c] driver_probe_device+0x12c/0x220 [00000000005b6da8] __driver_attach+0x88/0xa0 [00000000005b4df4] bus_for_each_dev+0x54/0xa0 [00000000005b5a54] bus_add_driver+0x154/0x260 [00000000005b7190] driver_register+0x50/0x180 [00000000006d250c] sunsu_init+0x18c/0x1e0 [00000000006c2668] do_one_initcall+0xe8/0x160 [00000000006c282c] kernel_init_freeable+0x12c/0x1e0 [0000000000603764] kernel_init+0x4/0x100 [0000000000405f64] ret_from_syscall+0x1c/0x2c [0000000000000000] (null) 1)Fix the panic; 2)Increment registered port number every successful probe. Signed-off-by: Kirill Tkhai CC: David Miller Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/sunsu.c | 21 +++++++++------------ 1 file changed, 9 insertions(+), 12 deletions(-) --- a/drivers/tty/serial/sunsu.c +++ b/drivers/tty/serial/sunsu.c @@ -968,6 +968,7 @@ static struct uart_ops sunsu_pops = { #define UART_NR 4 static struct uart_sunsu_port sunsu_ports[UART_NR]; +static int nr_inst; /* Number of already registered ports */ #ifdef CONFIG_SERIO @@ -1337,13 +1338,8 @@ static int __init sunsu_console_setup(st printk("Console: ttyS%d (SU)\n", (sunsu_reg.minor - 64) + co->index); - /* - * Check whether an invalid uart number has been specified, and - * if so, search for the first available port that does have - * console support. - */ - if (co->index >= UART_NR) - co->index = 0; + if (co->index > nr_inst) + return -ENODEV; port = &sunsu_ports[co->index].port; /* @@ -1408,7 +1404,6 @@ static enum su_type __devinit su_get_typ static int __devinit su_probe(struct platform_device *op) { - static int inst; struct device_node *dp = op->dev.of_node; struct uart_sunsu_port *up; struct resource *rp; @@ -1418,16 +1413,16 @@ static int __devinit su_probe(struct pla type = su_get_type(dp); if (type == SU_PORT_PORT) { - if (inst >= UART_NR) + if (nr_inst >= UART_NR) return -EINVAL; - up = &sunsu_ports[inst]; + up = &sunsu_ports[nr_inst]; } else { up = kzalloc(sizeof(*up), GFP_KERNEL); if (!up) return -ENOMEM; } - up->port.line = inst; + up->port.line = nr_inst; spin_lock_init(&up->port.lock); @@ -1461,6 +1456,8 @@ static int __devinit su_probe(struct pla } dev_set_drvdata(&op->dev, up); + nr_inst++; + return 0; } @@ -1488,7 +1485,7 @@ static int __devinit su_probe(struct pla dev_set_drvdata(&op->dev, up); - inst++; + nr_inst++; return 0; -- 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/