Re: [PATCH] staging: Check against NULL in fw_download_code

[Randy Dunlap <rdunlap@infradead.org>]

On 08/11/14 11:04, Nick Krause wrote:
> On Mon, Aug 11, 2014 at 2:02 PM, Nicholas Krause <xerofoify@gmail.com> wrote:
>> I am fixing the bug entry , https://bugzilla.kernel.org/show_bug.cgi?id=60461.
>> This entry states that we are not checking the skb allocated in fw_download_code
>> and after checking I fixed it to check for the NULL value before using the allocate
>> skb.
>>
>> Signed-off-by: Nicholas Krause <xerofoify@gmail.com>
>> ---
>>  drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c | 14 ++++++++------
>>  1 file changed, 8 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c b/drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c
>> index 1a95d1f..0a4c926 100644
>> --- a/drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c
>> +++ b/drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c
>> @@ -60,13 +60,15 @@ static bool fw_download_code(struct net_device *dev, u8 *code_virtual_address,
>>
>>                 }
>>
>> -               skb  = dev_alloc_skb(frag_length + 4);
>> -               memcpy((unsigned char *)(skb->cb), &dev, sizeof(dev));
>> -               tcb_desc = (struct cb_desc *)(skb->cb + MAX_DEV_ADDR_SIZE);
>> -               tcb_desc->queue_index = TXCMD_QUEUE;
>> -               tcb_desc->bCmdOrInit = DESC_PACKET_TYPE_INIT;
>> -               tcb_desc->bLastIniPkt = bLastIniPkt;
>>
>> +               skb  = dev_alloc_skb(frag_length + 4);
>> +               if (skb) {
>> +                       memcpy((unsigned char *)(skb->cb), &dev, sizeof(dev));
>> +                       tcb_desc = (struct cb_desc *)(skb->cb + MAX_DEV_ADDR_SIZE);
>> +                       tcb_desc->queue_index = TXCMD_QUEUE;
>> +                       tcb_desc->bCmdOrInit = DESC_PACKET_TYPE_INIT;
>> +                       tcb_desc->bLastIniPkt = bLastIniPkt;
>> +               }

and what happens here (below) if skb is NULL?

>>                 seg_ptr = skb->data;
>>                 for (i = 0; i < frag_length; i += 4) {
>>                         *seg_ptr++ = ((i+0) < frag_length) ?
>> --
>> 1.9.1
>>
> And I did check it against Linus's tree to make sure it applies , just
> to let you known.
> Nick


-- 
~Randy