[3.8.y.z extended stable] Patch "power: max17040: Fix NULL pointer dereference when there is no" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    power: max17040: Fix NULL pointer dereference when there is no

to the linux-3.8.y-queue branch of the 3.8.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-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.19.

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

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 8f555a007c512cad8e48dede8432bacbb081fda3 Mon Sep 17 00:00:00 2001
From: Krzysztof Kozlowski <k.kozlowski at samsung.com>
Date: Thu, 30 Jan 2014 14:32:45 +0100
Subject: power: max17040: Fix NULL pointer dereference when there is no
 platform_data

commit ac323d8d807060f7c95a685a9fe861e7b6300993 upstream.

Fix NULL pointer dereference of "chip->pdata" if platform_data was not
supplied to the driver.

The driver during probe stored the pointer to the platform_data:
	chip->pdata = client->dev.platform_data;
Later it was dereferenced in max17040_get_online() and
max17040_get_status().

If platform_data was not supplied, the NULL pointer exception would
happen:

[    6.626094] Unable to handle kernel  of a at virtual address 00000000
[    6.628557] pgd = c0004000
[    6.632868] [00000000] *pgd=66262564
[    6.634636] Unable to handle kernel paging request at virtual address e6262000
[    6.642014] pgd = de468000
[    6.644700] [e6262000] *pgd=00000000
[    6.648265] Internal error: Oops: 5 [#1] PREEMPT SMP ARM
[    6.653552] Modules linked in:
[    6.656598] CPU: 0 PID: 31 Comm: kworker/0:1 Not tainted 3.10.14-02717-gc58b4b4 #505
[    6.664334] Workqueue: events max17040_work
[    6.668488] task: dfa11b80 ti: df9f6000 task.ti: df9f6000
[    6.673873] PC is at show_pte+0x80/0xb8
[    6.677687] LR is at show_pte+0x3c/0xb8
[    6.681503] pc : [<c001b7b8>]    lr : [<c001b774>]    psr: 600f0113
[    6.681503] sp : df9f7d58  ip : 600f0113  fp : 00000009
[    6.692965] r10: 00000000  r9 : 00000000  r8 : dfa11b80
[    6.698171] r7 : df9f7ea0  r6 : e6262000  r5 : 00000000  r4 : 00000000
[    6.704680] r3 : 00000000  r2 : e6262000  r1 : 600f0193  r0 : c05b3750
[    6.711194] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
[    6.718485] Control: 10c53c7d  Table: 5e46806a  DAC: 00000015
[    6.724218] Process kworker/0:1 (pid: 31, stack limit = 0xdf9f6238)
[    6.730465] Stack: (0xdf9f7d58 to 0xdf9f8000)
[    6.914325] [<c001b7b8>] (show_pte+0x80/0xb8) from [<c047107c>] (__do_kernel_fault.part.9+0x44/0x74)
[    6.923425] [<c047107c>] (__do_kernel_fault.part.9+0x44/0x74) from [<c001bb7c>] (do_page_fault+0x2c4/0x360)
[    6.933144] [<c001bb7c>] (do_page_fault+0x2c4/0x360) from [<c0008400>] (do_DataAbort+0x34/0x9c)
[    6.941825] [<c0008400>] (do_DataAbort+0x34/0x9c) from [<c000e5d8>] (__dabt_svc+0x38/0x60)
[    6.950058] Exception stack(0xdf9f7ea0 to 0xdf9f7ee8)
[    6.955099] 7ea0: df0c1790 00000000 00000002 00000000 df0c1794 df0c1790 df0c1790 00000042
[    6.963271] 7ec0: df0c1794 00000001 00000000 00000009 00000000 df9f7ee8 c0306268 c0306270
[    6.971419] 7ee0: a00f0113 ffffffff
[    6.974902] [<c000e5d8>] (__dabt_svc+0x38/0x60) from [<c0306270>] (max17040_work+0x8c/0x144)
[    6.983317] [<c0306270>] (max17040_work+0x8c/0x144) from [<c003f364>] (process_one_work+0x138/0x440)
[    6.992429] [<c003f364>] (process_one_work+0x138/0x440) from [<c003fa64>] (worker_thread+0x134/0x3b8)
[    7.001628] [<c003fa64>] (worker_thread+0x134/0x3b8) from [<c00454bc>] (kthread+0xa4/0xb0)
[    7.009875] [<c00454bc>] (kthread+0xa4/0xb0) from [<c000eb28>] (ret_from_fork+0x14/0x2c)
[    7.017943] Code: e1a03005 e2422480 e0826104 e59f002c (e7922104)
[    7.024017] ---[ end trace 73bc7006b9cc5c79 ]---

Signed-off-by: Krzysztof Kozlowski <k.kozlowski at samsung.com>
Fixes: c6f4a42de60b981dd210de01cd3e575835e3158e
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/power/max17040_battery.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/power/max17040_battery.c b/drivers/power/max17040_battery.c
index 22cfe9c..64de769 100644
--- a/drivers/power/max17040_battery.c
+++ b/drivers/power/max17040_battery.c
@@ -148,7 +148,7 @@ static void max17040_get_online(struct i2c_client *client)
 {
 	struct max17040_chip *chip = i2c_get_clientdata(client);

-	if (chip->pdata->battery_online)
+	if (chip->pdata && chip->pdata->battery_online)
 		chip->online = chip->pdata->battery_online();
 	else
 		chip->online = 1;
@@ -158,7 +158,8 @@ static void max17040_get_status(struct i2c_client *client)
 {
 	struct max17040_chip *chip = i2c_get_clientdata(client);

-	if (!chip->pdata->charger_online || !chip->pdata->charger_enable) {
+	if (!chip->pdata || !chip->pdata->charger_online
+			|| !chip->pdata->charger_enable) {
 		chip->status = POWER_SUPPLY_STATUS_UNKNOWN;
 		return;
 	}
--
1.8.3.2