[PATCH AUTOSEL 6.0 16/77] wifi: mac80211: fix control port frame addressing

Sasha Levin
2022-10-09T22:10:39Z

From: Johannes Berg <johannes.berg@intel.com>

[ Upstream commit a6ba64d0b187109dc252969c1fc9e2525868bd49 ]

For an AP interface, when userspace specifieds the link ID to
transmit the control port frame on (in particular for the
initial 4-way-HS), due to the logic in ieee80211_build_hdr()
for a frame transmitted from/to an MLD, we currently build a
header with

A1 = DA = MLD address of the peer MLD
A2 = local link address (!)
A3 = SA = local MLD address

This clearly makes no sense, and leads to two problems:
- if the frame were encrypted (not true for the initial
4-way-HS) the AAD would be calculated incorrectly
- if iTXQs are used, the frame is dropped by logic in
ieee80211_tx_dequeue()

Fix the addressing, which fixes the first bullet, and the
second bullet for peer MLDs, I'll fix the second one for
non-MLD peers separately.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/mac80211/tx.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 13249e97a069..af7286617e46 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -2640,7 +2640,8 @@ static struct sk_buff *ieee80211_build_hdr(struct ieee80211_sub_if_data *sdata,
goto free;
}
memcpy(hdr.addr2, link->conf->addr, ETH_ALEN);
- } else if (link_id == IEEE80211_LINK_UNSPECIFIED) {
+ } else if (link_id == IEEE80211_LINK_UNSPECIFIED ||
+ (sta && sta->sta.mlo)) {
memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
} else {
struct ieee80211_bss_conf *conf;
--
2.35.1