wifi: mac80211: don't allow deactivation of all links

The set_active_links API is intended for link switching, so switching
to no links at all is not supported.
Add a warning to check that.

Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20240129200054.e3c113f94508.Ia35f927f914bf98dd8f9350dd4f78b1d901b1c1d@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/link.c b/net/mac80211/link.c
index d4f86955afa6d01359f336e4086e0a21af509e0d..c0d05efcf6f8c8dd96b178e2e625b2227b23d932 100644 (file)
--- a/net/mac80211/link.c
+++ b/net/mac80211/link.c
@@ -444,6 +444,9 @@ int ieee80211_set_active_links(struct ieee80211_vif *vif, u16 active_links)
 
        lockdep_assert_wiphy(local->hw.wiphy);
 
+       if (WARN_ON(!active_links))
+               return -EINVAL;
+
        if (!drv_can_activate_links(local, sdata, active_links))
                return -EINVAL;
 
@@ -472,6 +475,9 @@ void ieee80211_set_active_links_async(struct ieee80211_vif *vif,
 {
        struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 
+       if (WARN_ON(!active_links))
+               return;
+
        if (!ieee80211_sdata_running(sdata))
                return;