[PATCH] ACPI battery: fix possible use after free in acpi_battery_add()

[PATCH] ACPI battery: fix possible use after free in acpi_battery_add()

[Mariusz Kozlowski]

When acpi_battery_add_fs() fails 'battery' will be kfreed and then
used again.

Signed-off-by: Mariusz Kozlowski <mk@lab.zgora.pl>
---
 drivers/acpi/battery.c |   15 ++++++---------
 1 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index fcc13ac..27375e7 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -978,18 +978,15 @@ static int acpi_battery_add(struct acpi_device *device)
 	acpi_battery_update(battery);
 #ifdef CONFIG_ACPI_PROCFS_POWER
 	result = acpi_battery_add_fs(device);
-#endif
-	if (!result) {
-		printk(KERN_INFO PREFIX "%s Slot [%s] (battery %s)\n",
-			ACPI_BATTERY_DEVICE_NAME, acpi_device_bid(device),
-			device->status.battery_present ? "present" : "absent");
-	} else {
-#ifdef CONFIG_ACPI_PROCFS_POWER
+	if (result) {
 		acpi_battery_remove_fs(device);
-#endif
 		kfree(battery);
+		return result;
 	}
-
+#endif
+	printk(KERN_INFO PREFIX "%s Slot [%s] (battery %s)\n",
+		ACPI_BATTERY_DEVICE_NAME, acpi_device_bid(device),
+		device->status.battery_present ? "present" : "absent");
 	battery->pm_nb.notifier_call = battery_notify;
 	register_pm_notifier(&battery->pm_nb);
 
-- 
1.7.0.4