Commit 0621809e authored Aug 03, 2015 by Krzysztof Kozlowski Committed by Jiri Kosina Aug 04, 2015

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 <k.kozlowski@samsung.com>
Reported-by: H.J. Lu <hjl.tools@gmail.com>
Fixes: 297d716f ("power_supply: Change ownership from driver to core")
Cc: <stable@vger.kernel.org>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>

parent 4a8e70f5

drivers/hid/hid-input.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -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 */

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