| Message ID | 1438560081-23055-1-git-send-email-k.kozlowski@samsung.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On 03.08.2015 09:01, Krzysztof Kozlowski wrote: > 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> > > --- > Changes since v1: > 1. Re-work idea, use local variable instead of devm-like functions > (pointed out by Dmitry Torokhov). > 2. Adjusted subject and commit message. I missed the warning: drivers/hid/hid-input.c:470:11: warning: assignment discards ‘const’ qualifier from pointer target type I'll fix this and send v3. Best regards, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c index 14aebe483219..460faaebaa2c 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) { + 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 */
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> --- Changes since v1: 1. Re-work idea, use local variable instead of devm-like functions (pointed out by Dmitry Torokhov). 2. Adjusted subject and commit message. --- drivers/hid/hid-input.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)