mac80211_hwsim: fix RCU protected chanctx access

We need to RCU protect the chanctx_conf access, so
do that.

Fixes: 585625c955b1 ("mac80211_hwsim: check TX and STA bandwidth")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20220505230421.fb8055c081a2.Ic6da3307c77a909bd61a0ea25dc2a4b08fe1b03f@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c
index 28bfa7b7b73c09ab0e6cad98b9587fc7b4bea39f..3ac3693dbecb668e42178eaed58cbb4d41dfd521 100644 (file)
--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -2202,11 +2202,14 @@ mac80211_hwsim_sta_rc_update(struct ieee80211_hw *hw,
        if (!data->use_chanctx) {
                confbw = data->bw;
        } else {
-               struct ieee80211_chanctx_conf *chanctx_conf =
-                       rcu_dereference(vif->chanctx_conf);
+               struct ieee80211_chanctx_conf *chanctx_conf;
+
+               rcu_read_lock();
+               chanctx_conf = rcu_dereference(vif->chanctx_conf);
 
                if (!WARN_ON(!chanctx_conf))
                        confbw = chanctx_conf->def.width;
+               rcu_read_unlock();
        }
 
        WARN(bw > hwsim_get_chanwidth(confbw),