From 7c62940165e9ae4004ce4e6b5117330bab94df68 Mon Sep 17 00:00:00 2001 From: Luis Felipe Dominguez Vega Date: Wed, 29 Jul 2015 21:11:20 -0500 Subject: [PATCH] rtlwifi: Fix NULL dereference when PCI driver used as an AP In commit 33511b157bbcebaef853cc1811992b664a2e5862 ("rtlwifi: add support to send beacon frame"), the mechanism for sending beacons was established. That patch works correctly for rtl8192cu, but there is a possibility of getting the following warnings in the PCI drivers: WARNING: CPU: 1 PID: 2439 at net/mac80211/driver-ops.h:12 ieee80211_bss_info_change_notify+0x179/0x1d0 [mac80211]() wlp5s0: Failed check-sdata-in-driver check, flags: 0x0 The warning is followed by a NULL pointer dereference as follows: BUG: unable to handle kernel NULL pointer dereference at 0000000000000006 IP: [] rtl_get_tcb_desc+0x5e/0x760 [rtlwifi] This problem was reported at http://thread.gmane.org/gmane.linux.kernel.wireless.general/138645, but no solution was found at that time. The problem was also reported at https://bugzilla.kernel.org/show_bug.cgi?id=9744 and this solution was developed and tested there. The USB driver works with a NULL final argument in the adapter_tx() callback; however, the PCI drivers need a struct rtl_tcb_desc in that position. Fixes: 33511b157bbc ("rtlwifi: add support to send beacon frame.") Signed-off-by: Luis Felipe Dominguez Vega Signed-off-by: Larry Finger Cc: Stable [3.19+] Signed-off-by: Kalle Valo --- drivers/net/wireless/rtlwifi/core.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/rtlwifi/core.c b/drivers/net/wireless/rtlwifi/core.c index 3b3a88b53b11..585d0883c7e5 100644 --- a/drivers/net/wireless/rtlwifi/core.c +++ b/drivers/net/wireless/rtlwifi/core.c @@ -1015,9 +1015,12 @@ static void send_beacon_frame(struct ieee80211_hw *hw, { struct rtl_priv *rtlpriv = rtl_priv(hw); struct sk_buff *skb = ieee80211_beacon_get(hw, vif); + struct rtl_tcb_desc tcb_desc; - if (skb) - rtlpriv->intf_ops->adapter_tx(hw, NULL, skb, NULL); + if (skb) { + memset(&tcb_desc, 0, sizeof(struct rtl_tcb_desc)); + rtlpriv->intf_ops->adapter_tx(hw, NULL, skb, &tcb_desc); + } } static void rtl_op_bss_info_changed(struct ieee80211_hw *hw,