| Message ID | 20190503130909.GI29695@mwanda (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Felix Fietkau |
| Headers | show |
| Series | mt76: mt7615: Use after free in mt7615_mcu_set_bcn() | expand |
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org> > We dereference "skb" when we assign: > > req.pkt_len = cpu_to_le16(MT_TXD_SIZE + skb->len); > ^^^^^^^^ > So this patch just moves the dev_kfree_skb() down a bit to avoid the > use after free. > > Fixes: 04b8e65922f6 ("mt76: add mac80211 driver for MT7615 PCIe-based chipsets") > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > --- > drivers/net/wireless/mediatek/mt76/mt7615/mcu.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c > index ea67c6022fe6..dc1301effa24 100644 > --- a/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c > +++ b/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c > @@ -1270,7 +1270,6 @@ int mt7615_mcu_set_bcn(struct mt7615_dev *dev, struct ieee80211_vif *vif, > mt7615_mac_write_txwi(dev, (__le32 *)(req.pkt), skb, wcid, NULL, > 0, NULL); > memcpy(req.pkt + MT_TXD_SIZE, skb->data, skb->len); > - dev_kfree_skb(skb); > > req.omac_idx = mvif->omac_idx; > req.enable = en; > @@ -1281,6 +1280,7 @@ int mt7615_mcu_set_bcn(struct mt7615_dev *dev, struct ieee80211_vif *vif, > req.pkt_len = cpu_to_le16(MT_TXD_SIZE + skb->len); > req.tim_ie_pos = cpu_to_le16(MT_TXD_SIZE + tim_off); > > + dev_kfree_skb(skb); > skb = mt7615_mcu_msg_alloc(&req, sizeof(req)); > > return mt7615_mcu_msg_send(dev, skb, MCU_EXT_CMD_BCN_OFFLOAD, > -- > 2.18.0 >
diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c index ea67c6022fe6..dc1301effa24 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c +++ b/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c @@ -1270,7 +1270,6 @@ int mt7615_mcu_set_bcn(struct mt7615_dev *dev, struct ieee80211_vif *vif, mt7615_mac_write_txwi(dev, (__le32 *)(req.pkt), skb, wcid, NULL, 0, NULL); memcpy(req.pkt + MT_TXD_SIZE, skb->data, skb->len); - dev_kfree_skb(skb); req.omac_idx = mvif->omac_idx; req.enable = en; @@ -1281,6 +1280,7 @@ int mt7615_mcu_set_bcn(struct mt7615_dev *dev, struct ieee80211_vif *vif, req.pkt_len = cpu_to_le16(MT_TXD_SIZE + skb->len); req.tim_ie_pos = cpu_to_le16(MT_TXD_SIZE + tim_off); + dev_kfree_skb(skb); skb = mt7615_mcu_msg_alloc(&req, sizeof(req)); return mt7615_mcu_msg_send(dev, skb, MCU_EXT_CMD_BCN_OFFLOAD,
We dereference "skb" when we assign: req.pkt_len = cpu_to_le16(MT_TXD_SIZE + skb->len); ^^^^^^^^ So this patch just moves the dev_kfree_skb() down a bit to avoid the use after free. Fixes: 04b8e65922f6 ("mt76: add mac80211 driver for MT7615 PCIe-based chipsets") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> --- drivers/net/wireless/mediatek/mt76/mt7615/mcu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)