Patchwork [3.5.y.z,extended,stable] Patch "sunsu: Fix panic in case of nonexistent port at" has been added to staging queue

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Submitter Luis Henriques
Date March 25, 2013, 6:03 p.m.
Message ID <1364234608-10376-1-git-send-email-luis.henriques@canonical.com>
Download mbox | patch
Permalink /patch/230915/
State New
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Comments

Luis Henriques - March 25, 2013, 6:03 p.m.
This is a note to let you know that I have just added a patch titled

    sunsu: Fix panic in case of nonexistent port at

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

From d7581733b3f7ea70906cdc4d769e4dfb9a25c989 Mon Sep 17 00:00:00 2001
From: Tkhai Kirill <tkhai@yandex.ru>
Date: Sat, 23 Feb 2013 23:01:15 +0000
Subject: [PATCH] sunsu: Fix panic in case of nonexistent port at
 "console=ttySY" cmdline option

commit cb29529ea0030e60ef1bbbf8399a43d397a51526 upstream.

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: <sunsu_console_setup+0x78/0xe0>
RPC: <sunsu_console_setup+0x74/0xe0>
I7: <register_console+0x378/0x3e0>
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 <tkhai@yandex.ru>
CC: David Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 drivers/tty/serial/sunsu.c | 21 +++++++++------------
 1 file changed, 9 insertions(+), 12 deletions(-)

--
1.8.1.2

Patch

diff --git a/drivers/tty/serial/sunsu.c b/drivers/tty/serial/sunsu.c
index 675303b..76fa1fa 100644
--- 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(struct console *co, char *options)
 	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_type(struct device_node *dp)

 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 platform_device *op)

 	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 platform_device *op)
 		}
 		dev_set_drvdata(&op->dev, up);

+		nr_inst++;
+
 		return 0;
 	}

@@ -1488,7 +1485,7 @@  static int __devinit su_probe(struct platform_device *op)

 	dev_set_drvdata(&op->dev, up);

-	inst++;
+	nr_inst++;

 	return 0;