From 463454b5dbd8dbab6e2fc6c557329e5b811b9c32 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 5 Jun 2012 12:16:50 +0200 Subject: [PATCH] cfg80211: fix interface combinations check 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. Cc: stable@kernel.org Reported-by: Mohammed Shafi Shajakhan Signed-off-by: Johannes Berg Signed-off-by: John W. Linville --- net/wireless/util.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/net/wireless/util.c b/net/wireless/util.c index 55d99466babb..8f2d68fc3a44 100644 --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -935,6 +935,7 @@ int cfg80211_can_change_interface(struct cfg80211_registered_device *rdev, 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; @@ -961,6 +962,7 @@ int cfg80211_can_change_interface(struct cfg80211_registered_device *rdev, num[wdev_iter->iftype]++; total++; + used_iftypes |= BIT(wdev_iter->iftype); } mutex_unlock(&rdev->devlist_mtx); @@ -970,6 +972,7 @@ int cfg80211_can_change_interface(struct cfg80211_registered_device *rdev, 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]; @@ -984,6 +987,7 @@ int cfg80211_can_change_interface(struct cfg80211_registered_device *rdev, 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]) @@ -991,7 +995,20 @@ int cfg80211_can_change_interface(struct cfg80211_registered_device *rdev, 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: -- 2.20.1