2023-03-30 09:16:33

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH wireless 2/2] wifi: mac80211: fix potential null pointer dereference

rx->sta->amsdu_mesh_control is being passed to ieee80211_amsdu_to_8023s
without checking rx->sta. Since it doesn't make sense to accept A-MSDU
packets without a sta, simply add a check earlier.

Fixes: 6e4c0d0460bd ("wifi: mac80211: add a workaround for receiving non-standard mesh A-MSDU")
Signed-off-by: Felix Fietkau <[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 b7b584a28163..af57616d2f1d 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2933,7 +2933,7 @@ __ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx, u8 data_offset)
data_offset, true))
return RX_DROP_UNUSABLE;

- if (rx->sta && rx->sta->amsdu_mesh_control < 0) {
+ if (rx->sta->amsdu_mesh_control < 0) {
bool valid_std = ieee80211_is_valid_amsdu(skb, true);
bool valid_nonstd = ieee80211_is_valid_amsdu(skb, false);

@@ -3009,7 +3009,7 @@ ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
}
}

- if (is_multicast_ether_addr(hdr->addr1))
+ if (is_multicast_ether_addr(hdr->addr1) || !rx->sta)
return RX_DROP_UNUSABLE;

if (rx->key) {
--
2.39.0