Re: [PATCH] usb: dwc3: Fix dereferencing of null dwc->usb_psy

From: Heiko Thiery
Date: Wed Mar 03 2021 - 19:07:23 EST


Hi all,

> On Wed, Mar 3, 2021 at 6:00 PM Colin King <colin.king@xxxxxxxxxxxxx> wrote:
>>
>> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>>
>> Currently the null check logic on dwc->usb_psy is inverted as it allows
>> calls to power_supply_put with a null dwc->usb_psy causing a null
>> pointer dereference. Fix this by removing the ! operator.
>>
>> Addresses-Coverity: ("Dereference after null check")
>> Fixes: 59fa3def35de ("usb: dwc3: add a power supply for current control")
>
> Acked-by: Ray Chi <raychi@xxxxxxxxxx>
>
>> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>

Tested-by: Heiko Thiery <heiko.thiery@xxxxxxxxx>

>> ---
>> drivers/usb/dwc3/core.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
>> index d15f065849cd..94fdbe502ce9 100644
>> --- a/drivers/usb/dwc3/core.c
>> +++ b/drivers/usb/dwc3/core.c
>> @@ -1628,7 +1628,7 @@ static int dwc3_probe(struct platform_device *pdev)
>> assert_reset:
>> reset_control_assert(dwc->reset);
>>
>> - if (!dwc->usb_psy)
>> + if (dwc->usb_psy)
>> power_supply_put(dwc->usb_psy);
>>
>> return ret;
>> @@ -1653,7 +1653,7 @@ static int dwc3_remove(struct platform_device *pdev)
>> dwc3_free_event_buffers(dwc);
>> dwc3_free_scratch_buffers(dwc);
>>
>> - if (!dwc->usb_psy)
>> + if (dwc->usb_psy)
>> power_supply_put(dwc->usb_psy);
>>
>> return 0;
>> --
>> 2.30.0
>>

Thank you.

--
Heiko