Re: [PATCH] isdn: mISDN: Fix potential NULL pointer dereference of kzalloc

[Kangjie Lu <kjlu@umn.edu>]

On 3/2/19 3:26 PM, Gustavo A. R. Silva wrote:
>
> On 3/2/19 3:20 PM, Aditya Pakki wrote:
>> Allocating memory via kzalloc for phi may fail and causes a
>> NULL pointer dereference. This patch avoids such a scenario.
>>
> Was this detected by Coccinelle?


It was detected by an LLVM-based static analyzer we recently developed.


>
> If so, please mention it in the commit log.
>
> Thanks
> --
> Gustavo
>
>> Signed-off-by: Aditya Pakki <pakki001@umn.edu>
>> ---
>>   drivers/isdn/hardware/mISDN/hfcsusb.c | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/isdn/hardware/mISDN/hfcsusb.c b/drivers/isdn/hardware/mISDN/hfcsusb.c
>> index 124ff530da82..26e3182bbca8 100644
>> --- a/drivers/isdn/hardware/mISDN/hfcsusb.c
>> +++ b/drivers/isdn/hardware/mISDN/hfcsusb.c
>> @@ -263,6 +263,9 @@ hfcsusb_ph_info(struct hfcsusb *hw)
>>   	int i;
>>   
>>   	phi = kzalloc(struct_size(phi, bch, dch->dev.nrbchan), GFP_ATOMIC);
>> +	if (!phi)
>> +		return;
>> +
>>   	phi->dch.ch.protocol = hw->protocol;
>>   	phi->dch.ch.Flags = dch->Flags;
>>   	phi->dch.state = dch->state;
>>