[PATCH 6.6 320/396] wifi: mac80211: check/clear fast rx for non-4addr sta VLAN changes

Greg Kroah-Hartman
2024-04-01T16:52:14Z

From: Felix Fietkau <nbd@nbd.name>

commit 4f2bdb3c5e3189297e156b3ff84b140423d64685 upstream.

When moving a station out of a VLAN and deleting the VLAN afterwards, the
fast_rx entry still holds a pointer to the VLAN's netdev, which can cause
use-after-free bugs. Fix this by immediately calling ieee80211_check_fast_rx
after the VLAN change.

Cc: stable@vger.kernel.org
Reported-by: ranygh@riseup.net
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://msgid.link/20240316074336.40442-1-nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/mac80211/cfg.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -2187,15 +2187,14 @@ static int ieee80211_change_station(stru
}

if (sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
- sta->sdata->u.vlan.sta) {
- ieee80211_clear_fast_rx(sta);
+ sta->sdata->u.vlan.sta)
RCU_INIT_POINTER(sta->sdata->u.vlan.sta, NULL);
- }

if (test_sta_flag(sta, WLAN_STA_AUTHORIZED))
ieee80211_vif_dec_num_mcast(sta->sdata);

sta->sdata = vlansdata;
+ ieee80211_check_fast_rx(sta);
ieee80211_check_fast_xmit(sta);

if (test_sta_flag(sta, WLAN_STA_AUTHORIZED)) {