[PATCH AUTOSEL 6.11 062/244] wifi: mac80211: fix RCU list iterations

[Sasha Levin]

From: Johannes Berg <johannes.berg@xxxxxxxxx>

[ Upstream commit ac35180032fbc5d80b29af00ba4881815ceefcb6 ]

There are a number of places where RCU list iteration is
used, but that aren't (always) called with RCU held. Use
just list_for_each_entry() in most, and annotate iface
iteration with the required locks.

Reviewed-by: Miriam Rachel Korenblit <miriam.rachel.korenblit@xxxxxxxxx>
Link: https://patch.msgid.link/20240827094939.ed8ac0b2f897.I8443c9c3c0f8051841353491dae758021b53115e@changeid
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 net/mac80211/chan.c | 4 +++-
 net/mac80211/mlme.c | 2 +-
 net/mac80211/scan.c | 2 +-
 net/mac80211/util.c | 4 +++-
 4 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index e8567723e94d5..b72e4036526bf 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -286,7 +286,9 @@ ieee80211_get_max_required_bw(struct ieee80211_link_data *link)
 	enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
 	struct sta_info *sta;
 
-	list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) {
+	lockdep_assert_wiphy(sdata->local->hw.wiphy);
+
+	list_for_each_entry(sta, &sdata->local->sta_list, list) {
 		if (sdata != sta->sdata &&
 		    !(sta->sdata->bss && sta->sdata->bss == sdata->bss))
 			continue;
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index f9526bbc36337..3a0433e088906 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1231,7 +1231,7 @@ static bool ieee80211_add_vht_ie(struct ieee80211_sub_if_data *sdata,
 		bool disable_mu_mimo = false;
 		struct ieee80211_sub_if_data *other;
 
-		list_for_each_entry_rcu(other, &local->interfaces, list) {
+		list_for_each_entry(other, &local->interfaces, list) {
 			if (other->vif.bss_conf.mu_mimo_owner) {
 				disable_mu_mimo = true;
 				break;
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index b5f2df61c7f67..2dd84fc542b2a 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -504,7 +504,7 @@ static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
 	 * the scan was in progress; if there was none this will
 	 * just be a no-op for the particular interface.
 	 */
-	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
+	list_for_each_entry(sdata, &local->interfaces, list) {
 		if (ieee80211_sdata_running(sdata))
 			wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
 	}
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index c7ad9bc5973a0..aed72794d9fe3 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -751,7 +751,9 @@ static void __iterate_interfaces(struct ieee80211_local *local,
 	struct ieee80211_sub_if_data *sdata;
 	bool active_only = iter_flags & IEEE80211_IFACE_ITER_ACTIVE;
 
-	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
+	list_for_each_entry_rcu(sdata, &local->interfaces, list,
+				lockdep_is_held(&local->iflist_mtx) ||
+				lockdep_is_held(&local->hw.wiphy->mtx)) {
 		switch (sdata->vif.type) {
 		case NL80211_IFTYPE_MONITOR:
 			if (!(sdata->u.mntr.flags & MONITOR_FLAG_ACTIVE))
-- 
2.43.0