From a2c1d531854c4319610f1d83351213b47a633969 Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski Date: Fri, 20 Feb 2015 14:32:24 +0100 Subject: [PATCH] power_supply: ipaq_micro_battery: Check return values in probe The return values of create_singlethread_workqueue() and power_supply_register() calls were not checked and even on error probe() function returned 0. 1. If allocation of workqueue failed (returning NULL) then further accesses could lead to NULL pointer dereference. The queue_delayed_work() expects workqueue to be non-NULL. 2. If registration of power supply failed then during unbind the driver tried to unregister power supply which was not actually registered. This could lead to memory corruption because power_supply_unregister() unconditionally cleans up given power supply. Signed-off-by: Krzysztof Kozlowski Fixes: 00a588f9d27f ("power: add driver for battery reading on iPaq h3xxx") Cc: Signed-off-by: Sebastian Reichel --- drivers/power/ipaq_micro_battery.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/drivers/power/ipaq_micro_battery.c b/drivers/power/ipaq_micro_battery.c index 698cf1636bb8..96b15e003f3f 100644 --- a/drivers/power/ipaq_micro_battery.c +++ b/drivers/power/ipaq_micro_battery.c @@ -226,6 +226,7 @@ static struct power_supply micro_ac_power = { static int micro_batt_probe(struct platform_device *pdev) { struct micro_battery *mb; + int ret; mb = devm_kzalloc(&pdev->dev, sizeof(*mb), GFP_KERNEL); if (!mb) @@ -233,14 +234,30 @@ static int micro_batt_probe(struct platform_device *pdev) mb->micro = dev_get_drvdata(pdev->dev.parent); mb->wq = create_singlethread_workqueue("ipaq-battery-wq"); + if (!mb->wq) + return -ENOMEM; + INIT_DELAYED_WORK(&mb->update, micro_battery_work); platform_set_drvdata(pdev, mb); queue_delayed_work(mb->wq, &mb->update, 1); - power_supply_register(&pdev->dev, µ_batt_power); - power_supply_register(&pdev->dev, µ_ac_power); + + ret = power_supply_register(&pdev->dev, µ_batt_power); + if (ret < 0) + goto batt_err; + + ret = power_supply_register(&pdev->dev, µ_ac_power); + if (ret < 0) + goto ac_err; dev_info(&pdev->dev, "iPAQ micro battery driver\n"); return 0; + +ac_err: + power_supply_unregister(µ_ac_power); +batt_err: + cancel_delayed_work_sync(&mb->update); + destroy_workqueue(mb->wq); + return ret; } static int micro_batt_remove(struct platform_device *pdev) -- 2.39.5