3.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Johannes Berg <[email protected]>

commit 463454b5dbd8dbab6e2fc6c557329e5b811b9c32 upstream.

If a given interface combination doesn't contain
a required interface type then we missed checking
that and erroneously allowed it even though iface
type wasn't there at all. Add a check that makes
sure that all interface types are accounted for.

Reported-by: Mohammed Shafi Shajakhan <[email protected]>
Signed-off-by: Johannes Berg <[email protected]>
Signed-off-by: John W. Linville <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 net/wireless/util.c |   19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -936,6 +936,7 @@ int cfg80211_can_change_interface(struct
                                  enum nl80211_iftype iftype)
 {
        struct wireless_dev *wdev_iter;
+       u32 used_iftypes = BIT(iftype);
        int num[NUM_NL80211_IFTYPES];
        int total = 1;
        int i, j;
@@ -969,12 +970,14 @@ int cfg80211_can_change_interface(struct
 
                num[wdev_iter->iftype]++;
                total++;
+               used_iftypes |= BIT(wdev_iter->iftype);
        }
        mutex_unlock(&rdev->devlist_mtx);
 
        for (i = 0; i < rdev->wiphy.n_iface_combinations; i++) {
                const struct ieee80211_iface_combination *c;
                struct ieee80211_iface_limit *limits;
+               u32 all_iftypes = 0;
 
                c = &rdev->wiphy.iface_combinations[i];
 
@@ -989,6 +992,7 @@ int cfg80211_can_change_interface(struct
                        if (rdev->wiphy.software_iftypes & BIT(iftype))
                                continue;
                        for (j = 0; j < c->n_limits; j++) {
+                               all_iftypes |= limits[j].types;
                                if (!(limits[j].types & BIT(iftype)))
                                        continue;
                                if (limits[j].max < num[iftype])
@@ -996,7 +1000,20 @@ int cfg80211_can_change_interface(struct
                                limits[j].max -= num[iftype];
                        }
                }
-               /* yay, it fits */
+
+               /*
+                * Finally check that all iftypes that we're currently
+                * using are actually part of this combination. If they
+                * aren't then we can't use this combination and have
+                * to continue to the next.
+                */
+               if ((all_iftypes & used_iftypes) != used_iftypes)
+                       goto cont;
+
+               /*
+                * This combination covered all interface types and
+                * supported the requested numbers, so we're good.
+                */
                kfree(limits);
                return 0;
  cont:


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