From a9da90e618cd0669a22bcc06a96209db5dd96e9b Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 5 Nov 2025 15:41:19 +0100 Subject: [PATCH] wifi: mac80211: reject address change while connecting While connecting, the MAC address can already no longer be changed. The change is already rejected if netif_carrier_ok(), but of course that's not true yet while connecting. Check for auth_data or assoc_data, so the MAC address cannot be changed. Also more comprehensively check that there are no stations on the interface being changed - if any peer station is added it will know about our address already, so we cannot change it. Cc: stable@vger.kernel.org Fixes: 3c06e91b40db ("wifi: mac80211: Support POWERED_ADDR_CHANGE feature") Link: https://patch.msgid.link/20251105154119.f9f6c1df81bb.I9bb3760ede650fb96588be0d09a5a7bdec21b217@changeid Signed-off-by: Johannes Berg --- net/mac80211/iface.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index a7873832d4fa..0ca55b9655a7 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -223,6 +223,10 @@ static int ieee80211_can_powered_addr_change(struct ieee80211_sub_if_data *sdata if (netif_carrier_ok(sdata->dev)) return -EBUSY; + /* if any stations are set known (so they know this vif too), reject */ + if (sta_info_get_by_idx(sdata, 0)) + return -EBUSY; + /* First check no ROC work is happening on this iface */ list_for_each_entry(roc, &local->roc_list, list) { if (roc->sdata != sdata) @@ -242,12 +246,16 @@ static int ieee80211_can_powered_addr_change(struct ieee80211_sub_if_data *sdata ret = -EBUSY; } + /* + * More interface types could be added here but changing the + * address while powered makes the most sense in client modes. + */ switch (sdata->vif.type) { case NL80211_IFTYPE_STATION: case NL80211_IFTYPE_P2P_CLIENT: - /* More interface types could be added here but changing the - * address while powered makes the most sense in client modes. - */ + /* refuse while connecting */ + if (sdata->u.mgd.auth_data || sdata->u.mgd.assoc_data) + return -EBUSY; break; default: ret = -EOPNOTSUPP; -- 2.47.3