On Mon, Aug 11, 2014 at 3:04 PM, Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote: > On 08/11/14 11:55, Nick Krause wrote: >> On Mon, Aug 11, 2014 at 2:45 PM, Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote: >>> On 08/11/14 11:26, Nick Krause wrote: >>>> On Mon, Aug 11, 2014 at 2:07 PM, Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote: >>>>> On 08/11/14 11:04, Nick Krause wrote: >>>>>> On Mon, Aug 11, 2014 at 2:02 PM, Nicholas Krause <xerofoify@xxxxxxxxx> 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@xxxxxxxxx> >>>>>>> --- >>>>>>> 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? >>> >>> Nick, >>> I'm asking if you have completely fixed the bug or only partially fixed it. >>> The answer is that the patch is only a partial fix. If skb is NULL, there >>> is still a problem in the statement below here. The kernel will oops on >>> that reference to skb, which 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 >>>> Sorry Randy. >>>> I may be mis reading this, but are you asking me to write a different >>>> commit message or is this patch just another bad patch in my series of >>>> bad patches? >>> >>> >>> -- >>> ~Randy >> >> Randy , >> Thanks for the catch :). Would you recommend just putting it in the if >> statement I created or create a second if statement for >> code readability. > > Neither one of those choices. I suggest that the code immediately check for > skb == NULL and return 0 (or false) if it is NULL. Then the code below that check > won't need to be changed at all. > > > > -- > ~Randy Thanks Randy for your help otherwise is my patch good? Please let me known if there our any other issues. Regards Nick _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
