From: Larry Finger Date: Mon, 21 Dec 2015 23:05:08 +0000 (-0600) Subject: rtlwifi: rtl_pci: Fix kernel panic X-Git-Tag: firefly_0821_release~176^2~475^2~313 X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=78899f827ef13fd7b841acd023a12a2b740ca54e;p=firefly-linux-kernel-4.4.55.git rtlwifi: rtl_pci: Fix kernel panic commit f99551a2d39dc26ea03dc6761be11ac913eb2d57 upstream. 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 Signed-off-by: Kalle Valo Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/net/wireless/realtek/rtlwifi/pci.c b/drivers/net/wireless/realtek/rtlwifi/pci.c index f46c9d7f6528..7f471bff435c 100644 --- a/drivers/net/wireless/realtek/rtlwifi/pci.c +++ b/drivers/net/wireless/realtek/rtlwifi/pci.c @@ -801,7 +801,9 @@ static void _rtl_pci_rx_interrupt(struct ieee80211_hw *hw) 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 @@ static void _rtl_pci_rx_interrupt(struct ieee80211_hw *hw) 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);