kernel/HID-hid-input-Fix-accessing...

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From 0621809e37936e7c2b3eac9165cf2aad7f9189eb Mon Sep 17 00:00:00 2001
From: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Date: Mon, 3 Aug 2015 14:57:30 +0900
Subject: [PATCH] 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: 297d716f6260 ("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>
---
drivers/hid/hid-input.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index 3511bbab..e3c6364 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -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 */
--
2.4.3