[PATCH 3.8 112/166] power_supply: Fix Oops from NULL pointer dereference from wakeup_source_activate

From: Kamal Mostafa
Date: Wed Jan 15 2014 - 16:56:46 EST

3.8.13.16 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Shuah Khan <shuah.kh@xxxxxxxxxxx>

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@xxxxxxxxxxx>
Acked-by: Anton Vorontsov <anton@xxxxxxxxxx>
Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Anton Vorontsov <anton@xxxxxxxxxx>
[ kamal: backport to 3.8 (context) ]
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
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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