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

Randy Dunlap
2014-08-11T18:07:43Z

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