mac80211: disable powersave for broken APs

commit 05cb91085760ca378f28fc274fbf77fc4fd9886c upstream.

Only AID values 1-2007 are valid, but some APs have been
found to send random bogus values, in the reported case an
AP that was sending the AID field value 0xffff, an AID of
0x3fff (16383).

There isn't much we can do but disable powersave since
there's no way it can work properly in this case.

Reported-by: Bill C Riemers <briemers@redhat.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 0c5aed2257fb83f43d755b94ba612411211f753c..3fdac77b9cc344669ec8584f8a833addd43b7d7a 100644 (file)
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -373,6 +373,7 @@ struct ieee80211_if_managed {
 
        unsigned long timers_running; /* used for quiesce/restart */
        bool powersave; /* powersave requested for this iface */
+       bool broken_ap; /* AP is broken -- turn off powersave */
        enum ieee80211_smps_mode req_smps, /* requested smps mode */
                                 ap_smps, /* smps mode AP thinks we're in */
                                 driver_smps_mode; /* smps mode request */

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 7a334fdd8d6cf250896fac701be844141ada0b1c..1563250a5579a1f605e812f7dcac739c47583f00 100644 (file)
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -613,6 +613,9 @@ static bool ieee80211_powersave_allowed(struct ieee80211_sub_if_data *sdata)
        if (!mgd->powersave)
                return false;
 
+       if (mgd->broken_ap)
+               return false;
+
        if (!mgd->associated)
                return false;
 
@@ -1450,10 +1453,21 @@ static bool ieee80211_assoc_success(struct ieee80211_work *wk,
        capab_info = le16_to_cpu(mgmt->u.assoc_resp.capab_info);
 
        if ((aid & (BIT(15) | BIT(14))) != (BIT(15) | BIT(14)))
-               printk(KERN_DEBUG "%s: invalid aid value %d; bits 15:14 not "
-                      "set\n", sdata->name, aid);
+               printk(KERN_DEBUG
+                      "%s: invalid AID value 0x%x; bits 15:14 not set\n",
+                      sdata->name, aid);
        aid &= ~(BIT(15) | BIT(14));
 
+       ifmgd->broken_ap = false;
+
+       if (aid == 0 || aid > IEEE80211_MAX_AID) {
+               printk(KERN_DEBUG
+                      "%s: invalid AID value %d (out of range), turn off PS\n",
+                      sdata->name, aid);
+               aid = 0;
+               ifmgd->broken_ap = true;
+       }
+
        pos = mgmt->u.assoc_resp.variable;
        ieee802_11_parse_elems(pos, len - (pos - (u8 *) mgmt), &elems);