2019-08-27 22:47:24

by Denis Kenzior

Subject: [PATCH 0/2] mac80211: Control Port over nl80211 fixes

Couple of small fixes for Control Port handling in mac80211. The
original commit was working by some crazy luck in all testing, but
manifested itself on certain hardware that managed to drop PAE frames
with uncanny consistency.

Denis Kenzior (2):
mac80211: Don't memset RXCB prior to PAE intercept
mac80211: Correctly set noencrypt for PAE frames

net/mac80211/rx.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--
2.19.2

2019-08-27 22:47:24

by Denis Kenzior

Subject: [PATCH 1/2] mac80211: Don't memset RXCB prior to PAE intercept

In ieee80211_deliver_skb_to_local_stack intercepts EAPoL frames if
mac80211 is configured to do so and forwards the contents over nl80211.
During this process some additional data is also forwarded, including
whether the frame was received encrypted or not. Unfortunately just
prior to the call to ieee80211_deliver_skb_to_local_stack, skb->cb is
cleared, resulting in incorrect data being exposed over nl80211.

Fixes: 018f6fbf540d ("mac80211: Send control port frames over nl80211")
Cc: [email protected]
Signed-off-by: Denis Kenzior <[email protected]>
---
net/mac80211/rx.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 3c1ab870fefe..7c4aeac006fb 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2452,6 +2452,8 @@ static void ieee80211_deliver_skb_to_local_stack(struct sk_buff *skb,
cfg80211_rx_control_port(dev, skb, noencrypt);
dev_kfree_skb(skb);
} else {
+ memset(skb->cb, 0, sizeof(skb->cb));
+
/* deliver to local stack */
if (rx->napi)
napi_gro_receive(rx->napi, skb);
@@ -2546,8 +2548,6 @@ ieee80211_deliver_skb(struct ieee80211_rx_data *rx)

if (skb) {
skb->protocol = eth_type_trans(skb, dev);
- memset(skb->cb, 0, sizeof(skb->cb));
-
ieee80211_deliver_skb_to_local_stack(skb, rx);
}

--
2.19.2

2019-08-27 22:47:26

by Denis Kenzior

Subject: [PATCH 2/2] mac80211: Correctly set noencrypt for PAE frames

The noencrypt flag was intended to be set if the "frame was received
unencrypted" according to include/uapi/linux/nl80211.h. However, the
current behavior is opposite of this.

Cc: [email protected]
Fixes: 018f6fbf540d ("mac80211: Send control port frames over nl80211")
Signed-off-by: Denis Kenzior <[email protected]>
---
net/mac80211/rx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 7c4aeac006fb..8514c1f4ca90 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2447,7 +2447,7 @@ static void ieee80211_deliver_skb_to_local_stack(struct sk_buff *skb,
skb->protocol == cpu_to_be16(ETH_P_PREAUTH)) &&
sdata->control_port_over_nl80211)) {
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
- bool noencrypt = status->flag & RX_FLAG_DECRYPTED;
+ bool noencrypt = (status->flag & RX_FLAG_DECRYPTED) == 0;

cfg80211_rx_control_port(dev, skb, noencrypt);
dev_kfree_skb(skb);
--
2.19.2