if rtlpriv->use_new_trx_flow == true and we run out of memory
to alloc a new skb, we will directly jump to no_new tag with
buffer_desc == NULL. Then we will dereference this NULL pointer
in function _rtl_pci_init_one_rxdesc.
Signed-off-by: Yang Bai <[email protected]>
---
drivers/net/wireless/rtlwifi/pci.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/net/wireless/rtlwifi/pci.c b/drivers/net/wireless/rtlwifi/pci.c
index a62170e..7fe04d1 100644
--- a/drivers/net/wireless/rtlwifi/pci.c
+++ b/drivers/net/wireless/rtlwifi/pci.c
@@ -820,17 +820,19 @@ static void _rtl_pci_rx_interrupt(struct ieee80211_hw *hw)
pci_unmap_single(rtlpci->pdev, *((dma_addr_t *)skb->cb),
rtlpci->rxbuffersize, PCI_DMA_FROMDEVICE);
+ if (rtlpriv->use_new_trx_flow)
+ buffer_desc =
+ &rtlpci->rx_ring[rxring_idx].buffer_desc
+ [rtlpci->rx_ring[rxring_idx].idx];
+
/* get a new skb - if fail, old one will be reused */
new_skb = dev_alloc_skb(rtlpci->rxbuffersize);
if (unlikely(!new_skb))
goto no_new;
- if (rtlpriv->use_new_trx_flow) {
- buffer_desc =
- &rtlpci->rx_ring[rxring_idx].buffer_desc
- [rtlpci->rx_ring[rxring_idx].idx];
+ if (rtlpriv->use_new_trx_flow)
/*means rx wifi info*/
pdesc = (struct rtl_rx_desc *)skb->data;
- }
+
memset(&rx_status , 0 , sizeof(rx_status));
rtlpriv->cfg->ops->query_rx_desc(hw, &stats,
&rx_status, (u8 *)pdesc, skb);
--
2.3.1
On Fri, Mar 13, 2015 at 1:29 AM, Larry Finger <[email protected]> wrote:
> On 03/12/2015 06:33 AM, Yang Bai wrote:
>>
>> if rtlpriv->use_new_trx_flow == true and we run out of memory
>> to alloc a new skb, we will directly jump to no_new tag with
>> buffer_desc == NULL. Then we will dereference this NULL pointer
>> in function _rtl_pci_init_one_rxdesc.
>>
>> Signed-off-by: Yang Bai <[email protected]>
>
>
> Is the attached patch OK? I have tested it, but it is unlikely that I have
> hit any memory failures, thus that part needs to be checked by eye.
Looks good to me. Thanks very much for your review.
Yang
>
> Larry
>
>
On 03/12/2015 06:33 AM, Yang Bai wrote:
> if rtlpriv->use_new_trx_flow == true and we run out of memory
> to alloc a new skb, we will directly jump to no_new tag with
> buffer_desc == NULL. Then we will dereference this NULL pointer
> in function _rtl_pci_init_one_rxdesc.
>
> Signed-off-by: Yang Bai <[email protected]>
Is the attached patch OK? I have tested it, but it is unlikely that I have hit
any memory failures, thus that part needs to be checked by eye.
Larry
On 03/12/2015 06:33 AM, Yang Bai wrote:
> if rtlpriv->use_new_trx_flow == true and we run out of memory
> to alloc a new skb, we will directly jump to no_new tag with
> buffer_desc == NULL. Then we will dereference this NULL pointer
> in function _rtl_pci_init_one_rxdesc.
>
> Signed-off-by: Yang Bai <[email protected]>
Good catch. The only problem that I have is this fix adds even more branching to
this interrupt routine. At first glance, I should be able to set buffer_desc in
the earlier code where the code has already branched. For testing, an RTL8192EE
card will be needed. Do you have such a card?
Larry
> ---
> drivers/net/wireless/rtlwifi/pci.c | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/net/wireless/rtlwifi/pci.c b/drivers/net/wireless/rtlwifi/pci.c
> index a62170e..7fe04d1 100644
> --- a/drivers/net/wireless/rtlwifi/pci.c
> +++ b/drivers/net/wireless/rtlwifi/pci.c
> @@ -820,17 +820,19 @@ static void _rtl_pci_rx_interrupt(struct ieee80211_hw *hw)
> pci_unmap_single(rtlpci->pdev, *((dma_addr_t *)skb->cb),
> rtlpci->rxbuffersize, PCI_DMA_FROMDEVICE);
>
> + if (rtlpriv->use_new_trx_flow)
> + buffer_desc =
> + &rtlpci->rx_ring[rxring_idx].buffer_desc
> + [rtlpci->rx_ring[rxring_idx].idx];
> +
> /* get a new skb - if fail, old one will be reused */
> new_skb = dev_alloc_skb(rtlpci->rxbuffersize);
> if (unlikely(!new_skb))
> goto no_new;
> - if (rtlpriv->use_new_trx_flow) {
> - buffer_desc =
> - &rtlpci->rx_ring[rxring_idx].buffer_desc
> - [rtlpci->rx_ring[rxring_idx].idx];
> + if (rtlpriv->use_new_trx_flow)
> /*means rx wifi info*/
> pdesc = (struct rtl_rx_desc *)skb->data;
> - }
> +
> memset(&rx_status , 0 , sizeof(rx_status));
> rtlpriv->cfg->ops->query_rx_desc(hw, &stats,
> &rx_status, (u8 *)pdesc, skb);
>