[PATCH 4.16 112/272] mt76x2: fix possible NULL pointer dereferencing in mt76x2_tx()

Greg Kroah-Hartman
2018-05-28T11:09:34Z

From: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>

[ Upstream commit 6958b027435aa54d82bbef09a007fd287f439977 ]

Fix a theoretical NULL pointer dereferencing in mt76x2_tx routine that
can occurs for injected frames in a monitor vif since vif pointer could
be NULL for that interfaces

Fixes: 23405236460b ("mt76: fix transmission of encrypted mgmt frames")
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Acked-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/wireless/mediatek/mt76/mt76x2_tx.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/net/wireless/mediatek/mt76/mt76x2_tx.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x2_tx.c
@@ -36,9 +36,12 @@ void mt76x2_tx(struct ieee80211_hw *hw,

msta = (struct mt76x2_sta *) control->sta->drv_priv;
wcid = &msta->wcid;
+ /* sw encrypted frames */
+ if (!info->control.hw_key && wcid->hw_key_idx != -1)
+ control->sta = NULL;
}

- if (vif || (!info->control.hw_key && wcid->hw_key_idx != -1)) {
+ if (vif && !control->sta) {
struct mt76x2_vif *mvif;

mvif = (struct mt76x2_vif *) vif->drv_priv;