rtlwifi: rtl_pci: Fix kernel panic
In commit 38506ecefab9 (rtlwifi: rtl_pci: Start modification for new
drivers), a bug was introduced that causes a NULL pointer dereference.
As this bug only affects the infrequently used RTL8192EE and only under
low-memory conditions, it has taken a long time for the bug to show up.
The bug was reported on the linux-wireless mailing list and also at
https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/ as
bug #1527603 (kernel crashes due to rtl8192ee driver on ubuntu 15.10).
Fixes: 38506ecefab9 ("rtlwifi: rtl_pci: Start modification for new drivers")
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
diff --git a/drivers/net/wireless/realtek/rtlwifi/pci.c b/drivers/net/wireless/realtek/rtlwifi/pci.c
index f46c9d7..7f471bf 100644
--- a/drivers/net/wireless/realtek/rtlwifi/pci.c
+++ b/drivers/net/wireless/realtek/rtlwifi/pci.c
@@ -801,7 +801,9 @@
hw_queue);
if (rx_remained_cnt == 0)
return;
-
+ buffer_desc = &rtlpci->rx_ring[rxring_idx].buffer_desc[
+ rtlpci->rx_ring[rxring_idx].idx];
+ pdesc = (struct rtl_rx_desc *)skb->data;
} else { /* rx descriptor */
pdesc = &rtlpci->rx_ring[rxring_idx].desc[
rtlpci->rx_ring[rxring_idx].idx];
@@ -824,13 +826,6 @@
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];
- /*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);