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

Sasha Levin
2024-09-25T11:39:07Z

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

[ 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@intel.com>
Link: https://patch.msgid.link/20240827094939.ed8ac0b2f897.I8443c9c3c0f8051841353491dae758021b53115e@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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