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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 <mohammed@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Johannes Berg 2012-06-05 12:16:50 +02:00 committed by John W. Linville
parent 0e1fa7ef25
commit 463454b5db
1 changed files with 18 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
net/wireless/util.c
View File

@ -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: