HID: hid-input: Fix accessing freed memory during device disconnect

During unbinding the driver was dereferencing a pointer to memory
already freed by power_supply_unregister().

Driver was freeing its internal description of battery through pointers
stored in power_supply structure. However, because the core owns the
power supply instance, after calling power_supply_unregister() this
memory is freed and the driver cannot access these members.

Fix this by storing the pointer to internal description of battery in a
local variable before calling power_supply_unregister(), so the pointer
remains valid.

Signed-off-by: Krzysztof Kozlowski <[email protected]>
Reported-by: H.J. Lu <[email protected]>
Fixes: 297d716f62 ("power_supply: Change ownership from driver to core")
Cc: <[email protected]>
Reviewed-by: Dmitry Torokhov <[email protected]>
Signed-off-by: Jiri Kosina <[email protected]>
This commit is contained in:
Krzysztof Kozlowski 2015-08-03 14:57:30 +09:00 • committed by Jiri Kosina
commit 0621809e37

View file

@ -462,12 +462,15 @@ out:
static void hidinput_cleanup_battery(struct hid_device *dev)
{
const struct power_supply_desc *psy_desc;
if (!dev->battery)
return;
psy_desc = dev->battery->desc;
power_supply_unregister(dev->battery);
kfree(dev->battery->desc->name);
kfree(dev->battery->desc);
kfree(psy_desc->name);
kfree(psy_desc);
dev->battery = NULL;
}
#else /* !CONFIG_HID_BATTERY_STRENGTH */