releases/3.19.7/power_supply-ipaq_micro_battery-check-return-values-in-probe.patch

   1 From a2c1d531854c4319610f1d83351213b47a633969 Mon Sep 17 00:00:00 2001
   2 From: Krzysztof Kozlowski <k.kozlowski@samsung.com>
   3 Date: Fri, 20 Feb 2015 14:32:24 +0100
   4 Subject: power_supply: ipaq_micro_battery: Check return values in probe
   5
   6 From: Krzysztof Kozlowski <k.kozlowski@samsung.com>
   7
   8 commit a2c1d531854c4319610f1d83351213b47a633969 upstream.
   9
  10 The return values of create_singlethread_workqueue() and
  11 power_supply_register() calls were not checked and even on error probe()
  12 function returned 0.
  13
  14 1. If allocation of workqueue failed (returning NULL) then further
  15    accesses could lead to NULL pointer dereference. The
  16    queue_delayed_work() expects workqueue to be non-NULL.
  17
  18 2. If registration of power supply failed then during unbind the driver
  19    tried to unregister power supply which was not actually registered.
  20    This could lead to memory corruption because
  21    power_supply_unregister() unconditionally cleans up given power
  22    supply.
  23
  24 Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
  25 Fixes: 00a588f9d27f ("power: add driver for battery reading on iPaq h3xxx")
  26 Signed-off-by: Sebastian Reichel <sre@kernel.org>
  27 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  28
  29 ---
  30  drivers/power/ipaq_micro_battery.c |   21 +++++++++++++++++++--
  31  1 file changed, 19 insertions(+), 2 deletions(-)
  32
  33 --- a/drivers/power/ipaq_micro_battery.c
  34 +++ b/drivers/power/ipaq_micro_battery.c
  35 @@ -226,6 +226,7 @@ static struct power_supply micro_ac_powe
  36  static int micro_batt_probe(struct platform_device *pdev)
  37  {
  38         struct micro_battery *mb;
  39 +       int ret;
  40
  41         mb = devm_kzalloc(&pdev->dev, sizeof(*mb), GFP_KERNEL);
  42         if (!mb)
  43 @@ -233,14 +234,30 @@ static int micro_batt_probe(struct platf
  44
  45         mb->micro = dev_get_drvdata(pdev->dev.parent);
  46         mb->wq = create_singlethread_workqueue("ipaq-battery-wq");
  47 +       if (!mb->wq)
  48 +               return -ENOMEM;
  49 +
  50         INIT_DELAYED_WORK(&mb->update, micro_battery_work);
  51         platform_set_drvdata(pdev, mb);
  52         queue_delayed_work(mb->wq, &mb->update, 1);
  53 -       power_supply_register(&pdev->dev, &micro_batt_power);
  54 -       power_supply_register(&pdev->dev, &micro_ac_power);
  55 +
  56 +       ret = power_supply_register(&pdev->dev, &micro_batt_power);
  57 +       if (ret < 0)
  58 +               goto batt_err;
  59 +
  60 +       ret = power_supply_register(&pdev->dev, &micro_ac_power);
  61 +       if (ret < 0)
  62 +               goto ac_err;
  63
  64         dev_info(&pdev->dev, "iPAQ micro battery driver\n");
  65         return 0;
  66 +
  67 +ac_err:
  68 +       power_supply_unregister(&micro_ac_power);
  69 +batt_err:
  70 +       cancel_delayed_work_sync(&mb->update);
  71 +       destroy_workqueue(mb->wq);
  72 +       return ret;
  73  }
  74
  75  static int micro_batt_remove(struct platform_device *pdev)