mac80211: copy chandef from AP vif to VLANs

Instead of keeping track of all those special cases where
VLAN interfaces have no bss_conf.chandef, just make sure
they have the same as the AP interface they belong to.

Among others, this fixes a crash getting a VLAN's channel
from userspace since a NULL channel is returned as a good
result (return value 0) for VLANs since the commit below.

Cc: stable@vger.kernel.org [3.18 only]
Fixes: c12bc4885f4b3 ("mac80211: return the vif's chandef in ieee80211_cfg_get_channel()")
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
[rewrite commit log]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index c7c5142..5d6dae9 100644 (file)
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -932,6 +932,21 @@ ieee80211_vif_chanctx_reservation_complete(struct ieee80211_sub_if_data *sdata)
        }
 }
 
+static void
+ieee80211_vif_update_chandef(struct ieee80211_sub_if_data *sdata,
+                            const struct cfg80211_chan_def *chandef)
+{
+       struct ieee80211_sub_if_data *vlan;
+
+       sdata->vif.bss_conf.chandef = *chandef;
+
+       if (sdata->vif.type != NL80211_IFTYPE_AP)
+               return;
+
+       list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
+               vlan->vif.bss_conf.chandef = *chandef;
+}
+
 static int
 ieee80211_vif_use_reserved_reassign(struct ieee80211_sub_if_data *sdata)
 {
@@ -994,7 +1009,7 @@ ieee80211_vif_use_reserved_reassign(struct ieee80211_sub_if_data *sdata)
        if (sdata->vif.bss_conf.chandef.width != sdata->reserved_chandef.width)
                changed = BSS_CHANGED_BANDWIDTH;
 
-       sdata->vif.bss_conf.chandef = sdata->reserved_chandef;
+       ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
 
        if (changed)
                ieee80211_bss_info_change_notify(sdata, changed);
@@ -1336,7 +1351,7 @@ static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
                            sdata->reserved_chandef.width)
                                changed = BSS_CHANGED_BANDWIDTH;
 
-                       sdata->vif.bss_conf.chandef = sdata->reserved_chandef;
+                       ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
                        if (changed)
                                ieee80211_bss_info_change_notify(sdata,
                                                                 changed);
@@ -1507,7 +1522,7 @@ int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
                goto out;
        }
 
-       sdata->vif.bss_conf.chandef = *chandef;
+       ieee80211_vif_update_chandef(sdata, chandef);
 
        ret = ieee80211_assign_vif_chanctx(sdata, ctx);
        if (ret) {
@@ -1649,7 +1664,7 @@ int ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
                break;
        }
 
-       sdata->vif.bss_conf.chandef = *chandef;
+       ieee80211_vif_update_chandef(sdata, chandef);
 
        ieee80211_recalc_chanctx_chantype(local, ctx);
 

diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 82473d9..96c4572 100644 (file)
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -520,6 +520,7 @@ int ieee80211_do_open(struct wireless_dev *wdev, bool coming_up)
                sdata->vif.cab_queue = master->vif.cab_queue;
                memcpy(sdata->vif.hw_queue, master->vif.hw_queue,
                       sizeof(sdata->vif.hw_queue));
+               sdata->vif.bss_conf.chandef = master->vif.bss_conf.chandef;
                break;
                }
        case NL80211_IFTYPE_AP: