[3.8.y.z extended stable] Patch "power_supply: Fix Oops from NULL pointer dereference from" has been added to staging queue

Kamal Mostafa kamal at canonical.com
Mon Jan 13 19:24:15 UTC 2014


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

    power_supply: Fix Oops from NULL pointer dereference from

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 3.8.13.16.

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 bf470f0b12c39c42bb7b005e5ea832b36fb0fa99 Mon Sep 17 00:00:00 2001
From: Shuah Khan <shuah.kh at samsung.com>
Date: Fri, 22 Nov 2013 10:54:28 -0700
Subject: power_supply: Fix Oops from NULL pointer dereference from
 wakeup_source_activate

commit 80c6463e2fa3377febfc98a6672d92d07f3c26c1 upstream.

power_supply_register() calls device_init_wakeup() to register a wakeup
source before initializing dev_name. As a result, device_wakeup_enable()
end up registering wakeup source with a null name when
wakeup_source_register() gets called with dev_name(dev) which is null at
the time.

When kernel is booted with wakeup_source_activate enabled, it will panic
when the trace point code tries to dereference ws->name.

Fixed the problem by moving up the kobject_set_name() call prior to
accesses to dev_name(). Replaced kobject_set_name() with dev_set_name()
which is the right interface to be called from drivers. Fixed the call to
device_del() prior to device_add() in for wakeup_init_failed error
handling code.

Trace after the change:

            bash-2143  [003] d...   132.280697: wakeup_source_activate: BAT1 state=0x20001
     kworker/3:2-1169  [003] d...   132.281305: wakeup_source_deactivate: BAT1 state=0x30000

Oops message:

[  819.769934] device: 'BAT1': device_add
[  819.770078] PM: Adding info for No Bus:BAT1
[  819.770235] BUG: unable to handle kernel NULL pointer dereference at           (null)
[  819.770435] IP: [<ffffffff813381c0>] skip_spaces+0x30/0x30
[  819.770572] PGD 3efd90067 PUD 3eff61067 PMD 0
[  819.770716] Oops: 0000 [#1] SMP
[  819.770829] Modules linked in: arc4 iwldvm mac80211 x86_pkg_temp_thermal coretemp kvm_intel joydev i915 kvm uvcvideo ghash_clmulni_intel videobuf2_vmalloc aesni_intel videobuf2_memops videobuf2_core aes_x86_64 ablk_helper cryptd videodev iwlwifi lrw rfcomm gf128mul glue_helper bnep btusb media bluetooth parport_pc hid_generic ppdev snd_hda_codec_hdmi drm_kms_helper snd_hda_codec_realtek cfg80211 drm tpm_infineon samsung_laptop snd_hda_intel usbhid snd_hda_codec hid snd_hwdep snd_pcm microcode snd_page_alloc snd_timer psmouse i2c_algo_bit lpc_ich tpm_tis video wmi mac_hid serio_raw ext2 lp parport r8169 mii
[  819.771802] CPU: 0 PID: 2167 Comm: bash Not tainted 3.12.0+ #25
[  819.771876] Hardware name: SAMSUNG ELECTRONICS CO., LTD. 900X3C/900X3D/900X4C/900X4D/SAMSUNG_NP1234567890, BIOS P03AAC 07/12/2012
[  819.772022] task: ffff88002e6ddcc0 ti: ffff8804015ca000 task.ti: ffff8804015ca000
[  819.772119] RIP: 0010:[<ffffffff813381c0>]  [<ffffffff813381c0>] skip_spaces+0x30/0x30
[  819.772242] RSP: 0018:ffff8804015cbc70  EFLAGS: 00010046
[  819.772310] RAX: 0000000000000003 RBX: ffff88040cfd6d40 RCX: 0000000000000018
[  819.772397] RDX: 0000000000020001 RSI: 0000000000000000 RDI: 0000000000000000
[  819.772484] RBP: ffff8804015cbcc0 R08: 0000000000000000 R09: ffff8803f0768d40
[  819.772570] R10: ffffea001033b800 R11: 0000000000000000 R12: ffffffff81c519c0
[  819.772656] R13: 0000000000020001 R14: 0000000000000000 R15: 0000000000020001
[  819.772744] FS:  00007ff98309b740(0000) GS:ffff88041f200000(0000) knlGS:0000000000000000
[  819.772845] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  819.772917] CR2: 0000000000000000 CR3: 00000003f59dc000 CR4: 00000000001407f0
[  819.773001] Stack:
[  819.773030]  ffffffff81114003 ffff8804015cbcb0 0000000000000000 0000000000000046
[  819.773146]  ffff880409757a18 ffff8803f065a160 0000000000000000 0000000000020001
[  819.773273]  0000000000000000 0000000000000000 ffff8804015cbce8 ffffffff8143e388
[  819.773387] Call Trace:
[  819.773434]  [<ffffffff81114003>] ? ftrace_raw_event_wakeup_source+0x43/0xe0
[  819.773520]  [<ffffffff8143e388>] wakeup_source_report_event+0xb8/0xd0
[  819.773595]  [<ffffffff8143e3cd>] __pm_stay_awake+0x2d/0x50
[  819.773724]  [<ffffffff8153395c>] power_supply_changed+0x3c/0x90
[  819.773795]  [<ffffffff8153407c>] power_supply_register+0x18c/0x250
[  819.773869]  [<ffffffff813d8d18>] sysfs_add_battery+0x61/0x7b
[  819.773935]  [<ffffffff813d8d69>] battery_notify+0x37/0x3f
[  819.774001]  [<ffffffff816ccb7c>] notifier_call_chain+0x4c/0x70
[  819.774071]  [<ffffffff81073ded>] __blocking_notifier_call_chain+0x4d/0x70
[  819.774149]  [<ffffffff81073e26>] blocking_notifier_call_chain+0x16/0x20
[  819.774227]  [<ffffffff8109397a>] pm_notifier_call_chain+0x1a/0x40
[  819.774316]  [<ffffffff81095b66>] hibernate+0x66/0x1c0
[  819.774407]  [<ffffffff81093931>] state_store+0x71/0xa0
[  819.774507]  [<ffffffff81331d8f>] kobj_attr_store+0xf/0x20
[  819.774613]  [<ffffffff811f8618>] sysfs_write_file+0x128/0x1c0
[  819.774735]  [<ffffffff8118579d>] vfs_write+0xbd/0x1e0
[  819.774841]  [<ffffffff811861d9>] SyS_write+0x49/0xa0
[  819.774939]  [<ffffffff816d1052>] system_call_fastpath+0x16/0x1b
[  819.775055] Code: 89 f8 48 89 e5 f6 82 c0 a6 84 81 20 74 15 0f 1f 44 00 00 48 83 c0 01 0f b6 10 f6 82 c0 a6 84 81 20 75 f0 5d c3 66 0f 1f 44 00 00 <80> 3f 00 55 48 89 e5 74 15 48 89 f8 0f 1f 40 00 48 83 c0 01 80
[  819.775760] RIP  [<ffffffff813381c0>] skip_spaces+0x30/0x30
[  819.775881]  RSP <ffff8804015cbc70>
[  819.775949] CR2: 0000000000000000
[  819.794175] ---[ end trace c4ef25127039952e ]---

Signed-off-by: Shuah Khan <shuah.kh at samsung.com>
Acked-by: Anton Vorontsov <anton at enomsg.org>
Acked-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Anton Vorontsov <anton at enomsg.org>
[ kamal: backport to 3.8 (context) ]
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/power/power_supply_core.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
index 8a7cfb3..b89ca61 100644
--- a/drivers/power/power_supply_core.c
+++ b/drivers/power/power_supply_core.c
@@ -334,11 +334,11 @@ int power_supply_register(struct device *parent, struct power_supply *psy)
 	dev_set_drvdata(dev, psy);
 	psy->dev = dev;

-	INIT_WORK(&psy->changed_work, power_supply_changed_work);
-
-	rc = kobject_set_name(&dev->kobj, "%s", psy->name);
+	rc = dev_set_name(dev, "%s", psy->name);
 	if (rc)
-		goto kobject_set_name_failed;
+		goto dev_set_name_failed;
+
+	INIT_WORK(&psy->changed_work, power_supply_changed_work);

 	rc = device_add(dev);
 	if (rc)
@@ -366,8 +366,8 @@ register_cooler_failed:
 	psy_unregister_thermal(psy);
 register_thermal_failed:
 	device_del(dev);
-kobject_set_name_failed:
 device_add_failed:
+dev_set_name_failed:
 	put_device(dev);
 success:
 	return rc;
--
1.8.3.2





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