[PATCH] HID: hid-input: Fix accessing freed memory during driver unbind
From: Krzysztof Kozlowski <hidden>
Date: 2015-07-28 00:16:48
Also in:
linux-input, linux-pm, lkml
Subsystem:
hid core layer, the rest · Maintainers:
Jiri Kosina, Benjamin Tissoires, Linus Torvalds
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() the
driver cannot access these members.
Fix this by using resource-managed allocations so internal data will be
freed by pointers stored in resource-managed core.
Signed-off-by: Krzysztof Kozlowski <redacted>
Reported-by: H.J. Lu <redacted>
Fixes: 297d716f6260 ("power_supply: Change ownership from driver to core")
Cc: <redacted>
---
drivers/hid/hid-input.c | 13 ++++---------
1 file changed, 4 insertions(+), 9 deletions(-)
diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index 14aebe483219..5429a8497d51 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c@@ -408,15 +408,14 @@ static bool hidinput_setup_battery(struct hid_device *dev, unsigned report_type, if (dev->battery != NULL) goto out; /* already initialized? */ - psy_desc = kzalloc(sizeof(*psy_desc), GFP_KERNEL); + psy_desc = devm_kzalloc(&dev->dev, sizeof(*psy_desc), GFP_KERNEL); if (psy_desc == NULL) goto out; - psy_desc->name = kasprintf(GFP_KERNEL, "hid-%s-battery", dev->uniq); - if (psy_desc->name == NULL) { - kfree(psy_desc); + psy_desc->name = devm_kasprintf(&dev->dev, GFP_KERNEL, + "hid-%s-battery", dev->uniq); + if (psy_desc->name == NULL) goto out; - } psy_desc->type = POWER_SUPPLY_TYPE_BATTERY; psy_desc->properties = hidinput_battery_props;
@@ -449,8 +448,6 @@ static bool hidinput_setup_battery(struct hid_device *dev, unsigned report_type, if (IS_ERR(dev->battery)) { hid_warn(dev, "can't register power supply: %ld\n", PTR_ERR(dev->battery)); - kfree(psy_desc->name); - kfree(psy_desc); dev->battery = NULL; } else { power_supply_powers(dev->battery, &dev->dev);
@@ -466,8 +463,6 @@ static void hidinput_cleanup_battery(struct hid_device *dev) return; power_supply_unregister(dev->battery); - kfree(dev->battery->desc->name); - kfree(dev->battery->desc); dev->battery = NULL; } #else /* !CONFIG_HID_BATTERY_STRENGTH */
--
1.9.1